155 Sentences With "zygotes" | Random Sentence Generator

The eggs used to produce the zygotes did not carry that gene mutation.

Conspiracy theories aside, this confluence of zygotes is probably due to a number of factors.

Luckily, my insurance covers up to $10,000 in fertility treatments, and we ended up with eight viable zygotes.

All other viable zygotes can be stored for up to five years with your subscription to Matrixtech's Fertilife service.

He twice co-sponsored bills to establish that the Constitution protects the rights of zygotes from the moment of fertilization.

When the two sperm fertilize the two eggs, it results in two single-cell organisms (zygotes), which then divide and grow into embryos.

Cutting and correcting gene mutations The study used 75 human zygotes in which the father carried a mutation on the MYBPC3 gene, Belmonte said.

First, they found sperm cells from donor sperm with the mutation, then fertilized eggs with those sperm, and injected the zygotes with the Cas-9 protein.

"For these and other reasons, the whole notion of simply recovering ancient DNA and plugging it into living cells to generate zygotes is profoundly impractical," he said.

One zygote fertilized by one sperm can split into three, according to American Pregnancy, or one of two zygotes can split, creating two identicals and one fraternal multiple.

Fraternal twins happen when two different sperm cells fertilize two different eggs, creating two different zygotes, both of which end up implanted in the uterus as developing embryos.

Scientists don't really understand why the fertilized eggs—called zygotes at this point—decide to split, but it doesn't happen as often as two separate sperm fertilizing two separate eggs.

In modern genetics, a chimera exists when a single organism is composed of cells from different zygotes, often resulting in a living thing with both male and female sex organs.

Then, the zygotes' own DNA-repair mechanism replaced what was cut out with a copy of a MYBPC3 gene from the mother, which did not carry a mutation, Belmonte said.

The landmark study demonstrates that gene editing technology can successfully repair faulty genes in the human germline — a scientific term that refers to sperm or egg cells, zygotes, and embryos.

The edits were made early in the embryonic stage, removing the bit of gene in a laboratory while the piglets were still merely zygotes then implanting the embryos into mother pigs.

They combined these with some of their cache of northern sperm and coaxed seven of the resulting zygotes through the early stages of embryonic development, to the point where they could be implanted in the uterus of a southern white, who would act as a surrogate mother, with a reasonable hope of success.

To rapturous applause, he gloated that President Trump had assembled an "A-Team" of "great pro-life leaders": Tom Price, who twice sponsored legislation that would give full constitutional rights to zygotes; Ben Carson, who once likened abortion to slavery; Rick Perry, who signed Texas' notorious abortion restrictions—which were eventually declared unconstitutional by the Supreme Court—into law.

Echoing the lyrics of a Monty Python song, politicians in Oklahoma and Delaware introduced "Every Sperm is Sacred" amendments to personhood bills—both of which would define the start of life at the moment of conception, giving full civil rights to zygotes at every stage of embryonic development—which would interpret any semen deposited anywhere other than a woman's vagina as an action against an unborn child.

Many zygotes were adjacent to a persistent synergid with filiform apparatus.

Though originally thought unique to the animal kingdom, evidence of kin selection has been identified in the plant kingdom. Competition for resources between developing zygotes in plant ovaries increases when seeds are sired by different fathers. How developing zygotes differentiate between full siblings and half-siblings in the ovary is undetermined, but genetic interactions are thought to play a role. Nonetheless, competition between zygotes in the ovary is detrimental to the reproductive success of the mother plant, as fewer zygotes mature into seeds, and is also thought to harm the mother plant itself.

The relief contains depictions of waves, fish, and zygotes of marine species in terrazzo and ceramic.

Also, Chk1 has been shown to be activated by the Scc1 subunit of the protein cohesin, in zygotes.

After fertilization in the laboratory, the resulting early embryos or zygotes are placed into the woman's fallopian tubes using a laparoscope.

Isogametes of two different individuals fuse in pairs to form zygotes. These are then develops into microspheric form. The life cycle of Elphidium may be summarized as follows: the microspheric forms produce amoebulae by asexual fission which develops into megalospheric forms. The megalospheric forms produce flagellated isogametes which after syngamy produce zygotes that develop into microspheric forms.

Gynogenesis is like parthenogenesis in that diploid zygotes inheriting all chromosomes from their mother can develop without a genetic contribution from males.

A multiple pregnancy from a single zygote is called monozygotic, from two zygotes is called dizygotic, or from three or more zygotes is called polyzygotic. Similarly, the siblings themselves from a multiple birth may be referred to as monozygotic if they are identical or as polyzygotic if they are fraternal. Each fertilized egg (zygote) may produce a single embryo, or it may split into two or more embryos, each carrying the same genetic material. Fetuses resulting from different zygotes are called fraternal and share only 50% of their genetic material, as ordinary full siblings from separate births do.

A savior baby or savior sibling is a child who is born to provide an organ or cell transplant to a sibling that is affected with a fatal disease, such as cancer or Fanconi anemia, that can best be treated by hematopoietic stem cell transplantation. The savior sibling is conceived through in vitro fertilization. Fertilized zygotes are tested for genetic compatibility (human leukocyte antigen (HLA) typing), using preimplantation genetic diagnosis (PGD), and only zygotes that are compatible with the existing child are implanted. Zygotes are also tested to make sure they are free of the original genetic disease.

After release from the epithelial cell, a trophozoit associates with a second one and forms a gamont by forming a circle and fusing together (syzygy). Once no distinction between the two is visible, zygotes are formed. The zygotes are the only diploid lifestage in the lifecycle of G. garnhami. A cyst (oocyst) eventually is formed and the nucleus goes through a meiotic and mitotic division.

There are two types of viviparity in fish. In histotrophic viviparity, the zygotes develop in the female's oviducts, but she provides no direct nutrition; the embryos survive by eating her eggs or their unborn siblings. In hemotrophic viviparity, the zygotes are retained within the female and are provided with nutrients by her, often through some form of placenta. In seahorses and pipefish, it is the male that becomes pregnant.

TET3o is created by alternative promoter use and contains an additional first N-terminal exon coding for 11 amino acids. TET3o only occurs in oocytes and neurons and is not expressed in embryonic stem cells or in any other cell type or adult mouse tissue tested. Whereas TET1 expression can barely be detected in oocytes and zygotes, and TET2 is only moderately expressed, the TET3 variant TET3o shows extremely high levels of expression in oocytes and zygotes, but is nearly absent at the 2-cell stage. It is possible that TET3o, high in neurons, oocytes and zygotes at the one cell stage, is the major TET enzyme utilized when very large scale rapid demethylations occur in these cells.

TET3o is created by alternative promoter use and contains an additional first N-terminal exon coding for 11 amino acids. TET3o only occurs in oocytes and neurons and was not expressed in embryonic stem cells or in any other cell type or adult mouse tissue tested. Whereas TET1 expression can barely be detected in oocytes and zygotes, and TET2 is only moderately expressed, the TET3 variant TET3o shows extremely high levels of expression in oocytes and zygotes, but is nearly absent at the 2-cell stage. It is possible that TET3o, high in neurons, oocytes and zygotes at the one cell stage, is the major TET enzyme utilized when very large scale rapid demethylations occur in these cells.

TET3o only occurs in oocytes and the one cell stage of the zygote and is not expressed in embryonic stem cells or in any other cell type or adult mouse tissue tested. Whereas TET1 expression can barely be detected in oocytes and zygotes, and TET2 is only moderately expressed, the TET3 variant TET3o shows extremely high levels of expression in oocytes and zygotes, but is nearly absent at the 2-cell stage. It appears that TET3o, high in oocytes and zygotes at the one cell stage, is the major TET enzyme utilized when almost 100% rapid demethylation occurs in the paternal genome just after fertilization and before DNA replication begins (see DNA demethylation).

The female reproductive role takes over again in May with fertilization of the gametes to form zygotes. The cycle comes full circle in late summer once again, with spawning.

Failure of proper segregation during prophase II can also lead to aneuploid gametes. Aneuploid gametes can undergo fertilization to form aneuploid zygotes and hence to serious adverse consequences for progeny.

Symbiosis, Philadelphia, Pa.(USA) However, in recent years, through molecular methods, evidence of recombination and sexual fusions of gamates of the same size suggests the occurrence of sexual reproduction. The zygotes, quite distinct from zoospores, are 6.6 um in diameter and smooth walled with two round chloroplasts. First, the gametes pair up and fuse with each other, leading to the formation of zygotes. Then, the flagella disappear and the zygote develops in a normal vegetative pattern.

Fertilization was a not very noticeable process by which motile (able to move) gamete (male) approached an unmoving one (female) and, following contact, the two cells fused rapidly. Many zygotes having two eyespots and two chloroplasts can be identified in this process. The development of zygotes and unfused gametes follow the same pattern leading directly to the formation of parenchymatous sporophytes. Germination results in a branched filament having a terminal (not produced within the organism) hair.

Male gametocytes (microgamonts) divide to form flagellated microgametes, while female gametocytes (macrogamonts) concurrently differentiate into macrogametes, sometimes even within the same host cell. These gametes then fuse forming zygotes within the epithelial layer of the duodenum of the host. Subsequently, zygotes transition to an oocyst stage. This transition is marked by the formation of large refractile bodies within the oocysts, soon followed by the appearance of developing sporozoites. The mature octonucleate oocyst is a characteristic phase of Schellackia’s lifecycle.

Summary of Myxozoan Life Cycle In Myxozoan development, the Myxosporean life-stage develops inside a fish host, while the Actinosporean life-stage develops in an annelid host. Fully-developed Myxospores are consumed by annelids and reproduce asexually via schzogony in the gut epithelium of worms. Gametes are formed in the gut of the worm and these gametes fuse together to create eight zygotes. The zygotes become spores with three valves, 3 polar capsules, and a sporoplasm that are released in the worm's feces and attach to the surface of a fish host.

All five extant species show prolonged parental care of infants, with low rates of reproduction and relatively long life-spans. Monotremes are also noteworthy in their zygotic development: Most mammal zygotes go through holoblastic cleavage, meaning that after fertilization, the ovum splits into multiple, divisible daughter cells. In contrast, the zygotes of monotremes, like those of birds and reptiles, undergo meroblastic (partial) division. This means the cells at the yolk's edge have cytoplasm continuous with that of the egg, which allows the yolk and embryo to exchange waste and nutrients with the surrounding cytoplasm.

Tomatillos carry self-incompatible traits. The plant, i.e. the fertile hermaphrodite, is not able to produce zygotes after self-pollination occurs. This limits the ability to improve tomatillo production regarding the seed quality and the production of varieties.

A Chlamydomonas zygote contains chloroplast DNA (cpDNA) from both parents; such cells are generally rare, since normally cpDNA is inherited uniparentally from the mt+ mating type parent. These rare biparental zygotes allowed mapping of chloroplast genes by recombination.

Motomura, T. and Nagasato, C. (2003) The first spindle formation in brown algal zygotes. Hydrobiologia (in press). Nagasato, C. and Motomura, T. (2002) New pyrenoid formation in the brown alga, Scytosiphon lomentaria (Scytosiphonales, Phaeophyceae). Journal of Phycology 38: 800-806.

The D. salina zygote is extraordinarily hardy and can survive exposure to fresh water and to dryness. After germination, the zygotes release up to 32 haploid daughter cells.Lerche W. Untersuchungen über Entwicklung und Fortpflanzung in der Gattung Dunaliella. Arch f Protistenkd.

Also, in an unknown proportion of cases, two zygotes may fuse soon after fertilization, resulting in a single chimeric embryo, and, later, fetus. Chang and Eng Bunker, born in Siam (now Thailand) in 1811, were the origin of the term "Siamese twins".

Nearly all vertebrates undergo sexual reproduction. They produce haploid gametes by meiosis. The smaller, motile gametes are spermatozoa and the larger, non-motile gametes are ova. These fuse by the process of fertilisation to form diploid zygotes, which develop into new individuals.

Residual or somatic nuclei in 1 or 2 residual bodies later degenerate. The two zygotes each form a delimiting wall becoming oocysts. The oocysts are usually lemon shaped with polar plugs. Four or eight sporozoites are formed internally after 2 or 3 nuclear divisions respectively.

These are usually treated with glucocorticoids which often have serious side effects. Seliciclib has been shown to cause parthogenetic egg activation. However it does create abnormal second polar bodies and therefore possible aneuploid zygotes. Egg activation usually involves calcium oscillations however this does not happen with seliciclib.

Mature cells then associate to form sporadins and migrate to the crustacean's rectum, where they reproduce and form gametocysts (Clopton 2002). Zygotes divide to form sporozoites within the gametocysts, forming the gymnospores, the gametocyst ruptures and releases gymnospores through the crabs anus into the surrounding water (Clopton 2002).

Alexander's brittle stars reproduce by broadcast spawning. It is gonochoric, having individuals that are either male or female, with approximately equal numbers of each sex. Males and females release sperm and eggs into the sea where they meet for fertilization. These zygotes develop into free-swimming pluteus larva.

Zygotes affected with double hairless genes (1 in 4) never develop into puppies, and are reabsorbed in the womb. All Hairless Chinese Crested Dogs are therefore heterozygous. The Hairless variety can vary in amount of body hair. Fur on the muzzle, known as a beard, is not uncommon.

Once the flagellated cells reach the surface, they may lose their flagellae and form aplanospores, or thick-walled resting cells, or they may function as gametes, fusing in pairs to form zygotes. Many species feed on C. nivalis, including protozoans such as ciliates, rotifers, nematodes, ice worms and springtails.

When conditions are unfavourable due to prolonged dryness or exposure to low salinity waters, Dunaliella cells undergo sexual reproduction. Two haploid vegetative motile cells will touch flagella and then fuse their equal-sized gametes with one another in a very similar way to Chlamydomonas by the formation of a cytoplasmic bridge. After this isogamous fertilization, the diploid zygote, which is red and/or green in colour, develops a thick and smooth wall and takes on a circular shape very similar to the cyst form of Dunaliella. In fact, after observing zygotes, there was discussion on whether the cysts seen after and algal bloom at the Dead Sea in 1992 were in fact, zygotes.

However, each of those so-called traditional modes covered a wide range of diverse reproductive strategies. The biologist Thierry Lodé has accordingly proposed five modes of reproduction based on the relationship between the zygote (the fertilised egg) and the parents. His revised modes are ovuliparity, with external fertilisation; oviparity, with internal fertilisation of large eggs containing a substantial nutritive yolk; ovo-viviparity, that is oviparity where the zygotes are retained for a time in a parent's body, but without any sort of feeding by the parent; histotrophic viviparity, where the zygotes develop in the female's oviducts, but are fed on other tissues; and hemotrophic viviparity, where the developing embryos are fed by the mother, often through a placenta.

The first known publication of research into human germline editing was by a group of Chinese scientists in April 2015 in the Journal "Protein and Cell". The scientists used tripronuclear (3PN) zygotes, zygotes fertilized by two sperm and therefore non-viable, to investigate CRISPR/Cas9-mediated gene editing in human cells, something that had never been attempted before. The scientists found that while CRISPR/Cas9 could effectively cleave the β-globin gene (HBB), the efficiency of homologous recombination directed repair of HBB was highly inefficient and did not do so in a majority of the trials. Problems arose such as off target cleavage and the competitive recombination of the endogenous delta-globin with the HBB led to unexpected mutation.

The zoospores will then pair off, undergo plasmogamy, and form zygotes that will later form new plasmodia. The genus currently contains 4 species. The most notable member is Ceratiomyxa fruticulosa, a slime mould found in most parts of the world. Other known species of Ceratiomyxa are mostly found in the tropics.

Adult worms can live about 25 years in the host. Usually, only a single worm is present at time, but multiple worms are also reported. In each mature proglottid, self-fertilisation produces zygotes, which divide and differentiate into embryonated eggs called oncospheres. With thousands of oncospheres, the oldest gravid proglottids detach.

Development of parthenogens to adulthood is slower. Fewer parthenogens survive to adulthood and the adult lifespan of parthenogens is reduced. These findings suggest that there are specific constraints in switching from a meiotic mode of reproduction requiring fertilization to a parthenogenetic mode in which zygotes develop in the absence of fertilization.

Like vertebrates, most invertebrates reproduce at least partly through sexual reproduction. They produce specialized reproductive cells that undergo meiosis to produce smaller, motile spermatozoa or larger, non-motile ova. These fuse to form zygotes, which develop into new individuals. Others are capable of asexual reproduction, or sometimes, both methods of reproduction.

Randall Murphy left the group in June 1976, "citing mutual disagreement". Note: includes a double page photo of the group on pages 96 and 97 He was temporarily replaced by Little Russ Silver (a.k.a. Argentino Russo), and more permanently by Philip Foxman (ex-Zygotes, Prothalis) in late August. Murphy returned to Perth.

Under unfavourable conditions, some species will form a cyst. This is often the product of autogamy, in which case the cysts produced are zygotes. Cells undergoing this process withdraw their axopodia, adhere to the substrate, and take on an opaque and grayish appearance. This cyst then divides until only uninucleate cells remain.

As their environment dries out, asexual V. carteri quickly die. However, they are able to escape death by switching, shortly before drying is complete, to the sexual phase of their life cycle that leads to production of dormant desiccation-resistant zygotes. Sexual development is initiated by a glycoprotein pheromone (Hallmann et al., 1998).

The results of the study indicated that repair of HBB in the embryos occurred preferentially through alternative pathways. In the end only 4 of the 54 zygotes carried the intended genetic information, and even then the successfully edited embryos were mosaics containing the preferential genetic code and the mutation. The conclusion of the scientists was that further effort was needed in to improve the precision and efficiency of CRISPER/Cas9 gene editing. In March 2017 a group of Chinese scientists claimed to have edited three normal viable human embryos out of six total in the experiment. The study showed that CRISPR/Cas9 is could effectively be used as a gene-editing tool in human 2PN zygotes, which could lead potentially pregnancy viable if implanted.

Two-colored rose chimera A genetic chimerism or chimera (/kaɪˈmɪərə/ or /kɪˈmɪərə/ , also chimaera (chimæra)) is a single organism composed of cells with more than one distinct genotype. In animals, this means an individual derived from two or more zygotes, which can include possessing blood cells of different blood types, subtle variations in form (phenotype) and, if the zygotes were of differing sexes, then even the possession of both female and male sex organs (this is just one of many different phenomena that may result in intersexuality). Animal chimeras are produced by the merger of multiple fertilized eggs. In plant chimeras, however, the distinct types of tissue may originate from the same zygote, and the difference is often due to mutation during ordinary cell division.

The gamonts are aseptate. During syzygy gamont orientation differs between species (side to side, head to tail). A gametocyst wall forms around each pair of gamonts which then begin to divide into hundreds of gametes. Zygotes are produced by the fusion of two gametes and these in turn become surrounded by an oocyst wall.

Wied's marmoset at southern Bahia. Chimeric individuals carry two or more genetic cell lines in their bodies, each of which stems from a separate and genetically distinct zygote. This chimerism is the result of cell lines exchanged between siblings in utero. These two original zygotes were fertilized by two different sperm, which potentially came from more than one male.

Studies using the EmbryoScope (tm) time-lapse incubator have used several indicators for embryo quality, such as direct cleavage from 1 to 3 cells, as well as the initiation of compaction and start of blastulation. Also, two-pronuclear zygotes (2PN) transitioning through 1PN or 3PN states tend to develop into poorer-quality embryos than those that constantly remain 2PN.

Experimental systems for plant morphogenesis Coleochaete has a sterile jacket of cells that surround the gametangia and zygotes that are protected by a layer of sterile cells after fertilization. However, unlike land plants, Coleochaete has zygotic meiosis, meiosis taking place directly in the zygote and not in diploid cells resulting from mitotic division of the zygote.

Meiosis results in a random segregation of the genes that each parent contributes. Each parent organism is usually identical save for a fraction of their genes; each gamete is therefore genetically unique. At fertilisation, parental chromosomes combine. In humans, (2²²)² = 17.6x1012 chromosomally different zygotes are possible for the non- sex chromosomes, even assuming no chromosomal crossover.

If crossover occurs once, then on average (4²²)² = 309x1024 genetically different zygotes are possible for every couple, not considering that crossover events can take place at most points along each chromosome. The X and Y chromosomes undergo no crossover events and are therefore excluded from the calculation. The mitochondrial DNA is only inherited from the maternal parent.

The development of these parasites is mostly intracellular. Merogony results in the formation of about 150 elongate, slender merozoites which become spheroidal as they differentiate into amoeboid or spheroidal gamonts. The gamonts associate in syzygy and subdivide into gametes. Fusion of the gametes leads to numerous zygotes within the gametocyst which is either spherical or bilobed.

Research into zygotes of Drosophila have indicated that several segment polarity genes are vital for segmentation involved in neuroblast formation and differentiation of cell into their neuroblast identity; thereby, developing the central nervous system.Patel, N. H., Schafer, B., Goodman, C. S., & Holmgren, R. (1989). The role of segment polarity genes during Drosophila neurogenesis. Genes & development, 3(6), 890-904.

The gametes conjugate outside in open sea to produce zygotes and the B form then develops and matures during the second summer. Lister (1895) observed Elphidium in two different forms as megalospheric form (sexual form) and microsperic form (asexual form). The megalosperic form was developed from the microsperic form. The gametes which gives rise to microspheric form by syngamy.

In Cystogenes life cycle the resting sporangia (from the sporophyte) give rise to biflagellated, bi-nucleated zoospores that will encyst, undergo meiosis, and germinate to yield motile gametes. These gametes will then fuse in pairs and the resulting zygotes germinate and grow into new sporophytes. In the Brachyallomyces life cycle, the gametophytic stage is missing altogether.

Totipotency (Lat. totipotentia, "ability for all [things]") is the ability of a single cell to divide and produce all of the differentiated cells in an organism. Spores and zygotes are examples of totipotent cells. In the spectrum of cell potency, totipotency represents the cell with the greatest differentiation potential, being able to differentiate into any embryonic cell, as well as extraembryonic cells.

Between the ciliated cells are peg cells, which contain apical granules and produce tubular fluid. This fluid contains nutrients for spermatozoa, oocytes, and zygotes. The secretions also promote capacitation of the sperm by removing glycoproteins and other molecules from the plasma membrane of the sperm. Progesterone increases the number of peg cells, while estrogen increases their height and secretory activity.

All clitellata are hermaphrodites. During copulation, the clitellum produces a mucus that holds worms in place whilst they mate. During reproduction, the clitellum secretes a yolk (albumen) and a proteinaceous sheath which hardens. The worm then creeps out backward from the coat and deposits either fertilized zygotes or both ovae and sperm into the coat, which is then packed into a cocoon.

The sea anemone Aiptasia diaphana displays sexual plasticity. Thus asexually produced clones derived form a single founder individual can contain both male and female individuals (ramets). When eggs and sperm (gametes) are formed, they can produce zygotes derived from “selfing” (within the founding clone) or out-crossing, that then develop into swimming planula larvae. Anemones tend to grow and reproduce relatively slowly.

Vancouver, Canada, 24–28 May 1997. Of those that do implant, about 25% suffer early pregnancy loss by the sixth week LMP (after the woman's Last Menstrual Period), and an additional 7% miscarry or are stillborn. As a result, even without the use of birth control, between 50% and 70% of zygotes never result in established pregnancies, much less birth.

Additionally, transgenesis frequencies can be as high as 45% when using pronuclear injection into mouse zygotes. Sleeping Beauty Transposon System. Transposase enzyme can be expressed in cis or in trans to the gene cassette. The mechanism of the SBTS is similar to the Tn5 transposon system, however the enzyme and gene sequences are eukaryotic in nature as opposed to prokaryotic.

Astrephomene gubernaculifera has two mating types that reproduce to form zygotes. Schematic diagrams of the two mechanisms of spheroidal colony formation in the volvocine algae. In Astrephomene, rotation of daughter protoplasts occurs in conjunction with the movement of basal bodies during successive cell divisions. In Eudorina, protoplast rotation is lacking during successive divisions; a spheroidal colony is formed by means of inversion after successive divisions.

Implantation occurs approximately 14–16 days after mating. For the western spotted skunk, most copulations occur in late September and the beginning of October. Post copulation the zygotes are subject to normal cleavage but stop at the blastocyst stage, where they can remain in the uterus for roughly 6.5 months. After implantation, gestation last a 30 days and between April and June their offspring are born.

Volvox is facultatively sexual and can reproduce both sexually and asexually. In the lab, asexual reproduction is most commonly observed; the relative frequencies of sexual and asexual reproduction in the wild is unknown. The switch from asexual to sexual reproduction can be triggered by environmental conditions and by the production of a sex-inducing pheromone. Desiccation-resistant diploid zygotes are produced following successful fertilization.

Centrolecithal (Greek kentron = center of a circle, lekithos = yolk) describes the placement of the yolk in the centre of the cytoplasm of ova. Many arthropod eggs are centrolecithal. During cytokinesis, centrolecithal zygotes undergo meroblastic cleavage, where the cleavage plane extends only to the accumulated yolk and is superficial. This is due to the large dense yolk found within centrolecithal eggs and triggers a delayed embryonic development.

A majority of marine organisms utilize ocean currents and movement within the water column to reproduce. The process of releasing reproductive propagules into the water is called broadcast spawning. While broadcast spawning requires parents to be relatively close to each other for fertilization, the fertilized zygotes can be moved extreme distances. A number of marine invertebrates require ocean currents to connect their gametes once broadcast spawning has occurred.

During copulation, the male inseminates the female. The spermatozoon fertilizes an ovum or various ova in the uterus or fallopian tubes, and this results in one or multiple zygotes. Sometimes, a zygote can be created by humans outside of the animal's body in the artificial process of in-vitro fertilization. After fertilization, the newly formed zygote then begins to divide through mitosis, forming an embryo, which implants in the female's endometrium.

Motile male gametes will exit the antheridia and are chemotactically attracted to oogonia. A single sperm cell will pass through a pore opening in the oogonial cell wall, allowing fertilization. Zygotes (oospores) are initially green but will gradually become an orange-red colour and develop a thick multilayered cell wall with species specific surface adornments. Meiosis occurs in the zygote prior to germination, producing four multi-flagellated cells after germination.

The appearance of two pronuclei is the first sign of successful fertilization as observed during in vitro fertilisation, and is usually observed 18 hours after insemination or ICSI. The zygote is then termed a two- pronuclear zygote (2PN). Two-pronuclear zygotes transitioning through 1PN or 3PN states tend to develop into poorer-quality embryos than ones who remain 2PN throughout development, and may be significant in embryo selection in IVF.

However, these traits show some variation, most notably among the basal green algae called prasinophytes. Haploid algal cells (containing only one copy of their DNA) can fuse with other haploid cells to form diploid zygotes. When filamentous algae do this, they form bridges between cells, and leave empty cell walls behind that can be easily distinguished under the light microscope. This process is called conjugation and occurs for example in Spirogyra.

Female defenses select for ever more aggressive male sperm, however, leading to an evolutionary arms race. On the one hand, polyspermy creates inviable zygotes and lowers female fitness, but on the other, defenses may prevent fertilization altogether. This leads to a delicate compromise between the two, and has been suggested as one possible cause for the relatively high infertility rates seen in mammalian species., Morrow, E. H., G. Arnqvist, T. E. Pitcher. 2002.

Among sea anemones, sexual plasticity may occur. That is, asexually produced clones derived from a single founder individual can contain both male and female individuals (ramets). When eggs and sperm (gametes) are formed, they can produce zygotes derived from “selfing” (within the founding clone) or out-crossing, that then develop into swimming planula larvae. Polyps of a colony of Cnidaria The overwhelming majority of stony coral (Scleractinia) taxa are hermaphroditic in their adult colonies.

Such sperm DNA damage can be transmitted unrepaired into the egg where it is subject to removal by the maternal repair machinery. However, errors in maternal DNA repair of sperm DNA damage can result in zygotes with chromosomal structural aberrations. Melphalan is a bifunctional alkylating agent frequently used in chemotherapy. Meiotic inter-strand DNA damages caused by melphalan can escape paternal repair and cause chromosomal aberrations in the zygote by maternal misrepair.

They occasionally produce diploid planozygotes (mobile zygotes) implying they are capable of sexual reproduction. They have been observed to be in what appears to be the process of conjugation, a type of unicellular sexual reproduction. They can enter a hypnozygote cyst stage, which is an often thick walled, resting cyst that results from sexual fusion. This occurs when environmental conditions are adverse and allows it to be dormant and spread to grow algal blooms elsewhere.

Theodoxus fluviatilis feeds mainly on diatoms living on stones, scraping biofilms and also consuming detritus. It can also consume Cyanobacteria and green algae as a poor-quality food supply. Cyanobacteria contain toxins and indigestible mucopolysaccharides, and green algae have cellulose in their cell walls (Theodoxus species have no cellulase enzymes to digest cellulose). They also graze on zygotes and germlings of brown alga Fucus vesiculosus, when the alga is small up to 1 mm.

In developmental biology, cleavage is the division of cells in the early embryo. The process follows fertilisation, with the transfer being triggered by the activation of a cyclin-dependent kinase complex. The zygotes of many species undergo rapid cell cycles with no significant overall growth, producing a cluster of cells the same size as the original zygote. The different cells derived from cleavage are called blastomeres and form a compact mass called the morula.

The fertilization takes place in the stomach, where the zygotes can move into the midgut after they differentiate into motile version of the zygote, an ookinetes. Ookinetes then mature into oocytes inside the epithelial tissue of the midgut. Once grown, the oocyte ruptures and releases sporozoites into the salivary glands of the mosquito. The process then repeats itself through the human host if the mosquito lives long enough to infect a human.

The gametangia then fuse into a zygosporangium. In other fungi, cells from two hyphae with opposing mating types fuse, but only the cytoplasm is fused (plasmogamy). The two nuclei do not fuse, leading to the formation of a dikaryon cell that gives rise to a mycelium consisting of dikaryons. Karyogamy (fusion of nuclei) then eventually occurs in sporangia, and leads to the formation of diploid cells (zygotes) that immediately undergo meiosis to form spores.

During the second phase, the digits develop, and in the last phase, the egg tooth appears. Most mammal zygotes go through holoblastic cleavage, meaning that, following fertilisation, the ovum is split due to cell divisions into multiple, divisible daughter cells. This is in comparison to the more ancestral process of meroblastic cleavage, present in monotremes like the platypus and in non- mammals like reptiles and birds. In meroblastic cleavage, the ovum does not split completely.

This would result in one progeny cell line to be normal while the other cell line(s) to be abnormal. As a result the individual is considered to be a mosaic of normal and abnormal cells. Mosaicism is the occurrence of two or more cell lines with different genotypes within a single individual. It is different from chimerism which is the fusion of two zygotes, causing a new single zygote with two genotypes.

Plant zygotes germinate and divide repeatedly by mitosis to produce a diploid multicellular organism known as the sporophyte. The mature sporophyte produces haploid spores by meiosis that germinate and divide by mitosis to form a multicellular gametophyte phase that produces gametes at maturity. The gametophytes of different groups of plants vary in size. Mosses and other pteridophytic plants may have gametophytes consisting of several million cells, while angiosperms have as few as three cells in each pollen grain.

Reinforcement assists speciation by selecting against hybrids. Reinforcement is a process within speciation where natural selection increases the reproductive isolation between two populations of species by reducing the production of hybrids. Evidence for speciation by reinforcement has been gathered since the 1990s, and along with data from comparative studies and laboratory experiments, has overcome many of the objections to the theory. Differences in behavior or biology that inhibit formation of hybrid zygotes are termed prezygotic isolation.

These structures liberate gametes into the water and after fertilisation, the zygotes settle to the seabed. Tetrasporophyte plants develop from these and are at first indistinguishable from the gametophytes but when they become mature they develop spindle-shaped structures at the tips of the fronds measuring up to . These release tetraspores which develop into a new generation of gametophyte plants. It has been shown that the cycle is initiated by the short day conditions existing between October and April.

The modern concept of reinforcement originates from Theodosius Dobzhansky. He envisioned a species separated allopatrically, where during secondary contact the two populations mate, producing hybrids with lower fitness. Natural selection results from the hybrid's inability to produce viable offspring; thus members of one species who do not mate with members of the other have greater reproductive success. This favors the evolution of greater prezygotic isolation (differences in behavior or biology that inhibit formation of hybrid zygotes).

An animal chimera is a single organism that is composed of two or more different populations of genetically distinct cells that originated from different zygotes involved in sexual reproduction. If the different cells have emerged from the same zygote, the organism is called a mosaic. Chimeras are formed from at least four parent cells (two fertilised eggs or early embryos fused together). Each population of cells keeps its own character and the resulting organism is a mixture of tissues.

Some authors argue these species spawn simultaneously, but most reports support that the Orbicella species are temporally isolated by a few hours. Sperm and eggs are released packed in small bundles that break open when they reach the water surface due to the surface tension. Timing is important to improve the chances of gametes finding each other in the water column. In addition, gametes must be incompatible between species to prevent the formation of hybrid zygotes.

At that time, Herb Wagner showed that sterile A. × ebenoides was diploid, while the fertile individuals had arisen from the diploid by allopolyploidy and were tetraploid. Wagner went on to sow a large number of spores from a Maryland population of A. × ebenoides on culture media. While the vast majority of these were sterile, a small number were unreduced, diploid, and fertile. When these diploid spores fertilized one another, they formed allotetraploid zygotes that grew into sporophytes.

Pigs and wild boars ingest the infective embryo while grazing. The digestive enzymes will break the thick shell of the egg and allow formation of the zygotes called "oncospheres". These oncospheres then penetrate the mucous layer of the digestive tract and enter the circulation of the host. This is where the young larval stages form a pea-sized, fluid filled cyst, also known as “cysticercus”, which migrate to visceral organs like liver, serosa and lungs in pigs, and liver in cattle.

Both ova are then fertilized, each by a different sperm, and the coalesced zygotes undergo further cell duplications developing as a chimeric blastomere. If this blastomere then undergoes a twinning event, two embryos will be formed, with different paternal genetic information and identical maternal genetic information. This results in a set of twins with identical gene sequence from the mother's side, but different sequences from the father's side. Cells in each fetus carry chromosomes from either sperm, resulting in chimeras.

This means that all the organism's cytoplasm is used up in the creation of the gametes and only a husk remains at the site of the original plant. The plants are monoecious with male and female gametes being produced by the same plant and liberated into the water column where they unite to give spherical zygotes. These settle and after five weeks produce germ tubes which elongate and branch to develop into new plants.Culture studies on Caulerpa (caulerpales, chlorophyceae) III.

This species has a monoxenous life cycle with the only definitive host as chickens; it is extremely host-specific. Acquired via fecal contamination of food and water (oral-fecal route), it undergoes endogenous merogony in the crypts of Lieberkuhn (intestinal ceca of chicken) and gametogony in epithelial cells of the small intestines. Fusion of microgamete and macrogamete forms results in unsporulated zygotes, which are released with feces of chicken. The zygote sporulates after one to five days, and becomes infective.

When dispersed, they become amoeboid and make their way through the body wall of an adult worm before fertilising eggs in the metacoel. The resulting zygotes make their way out through the nephridiopores and become planktonic larvae. They may be brooded as an egg mass in the lophophoral cavity for a period. The larva is known as an actinotroch and was thought for a long time to be an adult organism in its own right and given the generic name Actinotrocha sabatieri.

In the absence of a large concentration of yolk, four major cleavage types can be observed in isolecithal cells: radial holoblastic, spiral holoblastic, bilateral holoblastic, and rotational holoblastic cleavage. These holoblastic cleavage planes pass all the way through isolecithal zygotes during the process of cytokinesis. Coeloblastula is the next stage of development for eggs that undergo this radial cleavaging. In mammals, because the isolecithal cells have only a small amount of yolk, they require immediate implantation onto the uterine wall to receive nutrients.

In most other seed plants, this second 'ventral canal nucleus' is normally found to be functionally useless. In Gnetum gnemon, numerous free egg nuclei exist in female cytoplasm inside the female gametophyte. Succeeding the penetration of the mature female gametophyte by the pollen tube, female cytoplasm and free nuclei move to surround the pollen tube. Released from the binucleate sperm cell are two sperm nuclei which then join with free egg nuclei to produce two viable zygotes, a homologous characteristic between families Ephedra and Gnetum.

Least common are identical triplets; three fetuses from one egg. In this case the original zygote divides into two, and then one of those two zygotes divides again but the other does not. Recently-born triplets in an incubator at ECWA Evangel Hospital, Jos, Nigeria March 29, 2004. Triplets are far less common than twins, according to the U.S. Centers for Disease Control and Prevention, accounting for only about 4300 sets in 3.9 million births, just a little more than 0.1%, or 1 in 1000.

Once feeding currents cause Nematopsis to enter its molluscan host, gymnospores first attach to the mollusc's gill or mantle depending on the species and penetrate the epithelium (Clopton 2002). They are then engulfed by the host's leukocytes and undergo presporonic growth (Clopton 2002). Once mature each sporozoite forms a resistant oocyst, which can be ingested by a crustacean host (Clopton 2002). Some Nematopsis species may from “heliospores” (bundles of female and male gametes) which are then transmitted to molluscs and form naked zygotes (Hatt 1931).

The exact life span of an adult worm is not determined; however, evidences from an outbreak among British military in the 1930s indicate that they can survive 2 to 5 years in humans. As a hermaphrodite, it reproduces by self-fertilisation, or cross- fertilisation if gametes are exchanged between two different proglottids. Spermatozoa fuse with the ova in the fertilisation duct, where the zygotes are produced. The zygote undergoes holoblastic and unequal cleavage resulting in three cell types, small, medium and large (micromeres, mesomeres, megameres).

Males are territorial and court females by flashing their colourful dorsal fins; the fins are also used to brace receptive females during the vibratory release of milt and roe. The fish are nonguarders: the eggs are left to mix with the substrate. Although the Arctic grayling does not excavate a nest, the highly energetic courtship and mating tends to kick up fine material which covers the zygotes. The zygote is small (approximately in diameter) and the embryo will hatch after two to three weeks.

Stylized cutaway diagram of an animal cell (with flagella) The kingdom Animalia contains multicellular organisms that are heterotrophic and motile (although some have secondarily adopted a sessile lifestyle). Most animals have bodies differentiated into separate tissues and these animals are also known as eumetazoans. They have an internal digestive chamber, with one or two openings; the gametes are produced in multicellular sex organs, and the zygotes include a blastula stage in their embryonic development. Metazoans do not include the sponges, which have undifferentiated cells.

A Powderpuff Chinese Crested Dog at a dog show in 2011 The Hairless allele (the wild type) is a dominant (and homozygous prenatal lethal) trait, while the Powderpuff allele acts as a simple recessive trait in its presence. Zygotes that receive two copies of the Hairless allele will never develop into puppies. Thus, all Chinese Crested Dogs carry at least one copy of the Powderpuff allele. The Powderpuff trait cannot be bred out because it is carried by all Chinese Crested Dogs (even the hairless ones).

In 1988 Britt Daniel formed his first band The Zygotes while in high school. In 1990, while a student at the University of Texas at Austin, Daniel formed his second band, Skellington, with Travis Hartnett, Mac Stringfellow, Paul Cannon and Mike Hurewitz. Skellington recorded and self-released This Town's Gone Dry in 1991, and the Skellington EP was released a year later in 1992. Before breaking up, the band released Skellington Rex, which contained songs that were re-recorded on Spoon's debut album Telephono.

4th ed. John Wiley & Sons, Ltd, pp.223-238. For example, if the strategy of parental care involves parents choosing to give each of a relatively small number of offspring an increased chance of surviving to reproduce themselves, they may accordingly have evolved to produce a small number of zygotes at a time, possibly only one. Parents need to trade off investment into current and future reproductive events, since parental care increases offspring survival at the expense of the parent's ability to invest in future broods.

The combination of recent discoveries in genetic engineering, particularly gene editing and the latest improvement in bovine reproduction technologies (e.g. in vitro embryo culture) allows for genome editing directly in fertilised oocytes using synthetic highly specific endonucleases. RNA-guided endonucleases:clustered regularly interspaced short palindromic repeats associated Cas9 (CRISPR/Cas9) are a new tool, further increasing the range of methods available. In particular CRISPR/Cas9 engineered endonucleases allows the use of multiple guide RNAs for simultaneous Knockouts (KO) in one step by cytoplasmic direct injection (CDI) on mammalian zygotes.

Different colonial ascidian species produce sexually derived offspring by one of two dispersal strategies - colonial species are either broadcast spawners (long-range dispersal) or philopatric (very short-range dispersal). Broadcast spawners release sperm and ova into the water column and fertilization occurs near to the parent colonies. Resultant zygotes develop into microscopic larvae that may be carried great distances by oceanic currents. The larvae of sessile forms which survive eventually settle and complete maturation on the substratum- then they may bud asexually to form a colony of zooids.

A common wall forms around the juxtaposed gamonts to form a gametocyst. Within this the two gamonts are now known as gametocytes The gametocyst enlarges from 5 to 15 µm in length while the gametocytes undergo nuclear division and the nuclei arrange themselves around the perimeter of the gametocytes except at the interface between the two cells. The peripheral cytoplasm condenses around the nuclei to form 16 isogametes within each gametocyte. The interface between the gametocytes breaks down and the gametes fuse forming as many as 16 zygotes.

Using her tail, the female digs a trough-shaped nest, called a redd (Scandinavian word for "nest"), in the gravel of the stream bed, where she deposits her eggs. As she expels the eggs, she is approached by one or more males, which fertilize them as they fall into the redd. Subsequently, the female covers the newly deposited zygotes, again with thrusts of her tail, against the gravel at the top of the redd. The female lays from 1,000 to 2,000 eggs in several clutches within the redd, often fertilized by different males.

A study indicated that fewer oocytes are recovered from cancer patients wanting to perform embryo preservation when compared with an age-matched control group, but the mean number of zygotes generated appears to be similar. The same study found that, of 65 patients referred to the program, 28% declined to undergo embryo, oocyte, or tissue cryopreservation. 9% were found not to be eligible for medical reasons. Of the remaining 41 patients, 85% chose to cryopreserve embryos, 10% chose to cryopreserve oocytes, and 5% chose to undergo ovarian tissue freezing.

The highly polymorphic nature of many P. falciparum proteins results in significant challenges to vaccine design. Vaccine candidates that target antigens on gametes, zygotes, or ookinetes in the mosquito midgut aim to block the transmission of malaria. These transmission-blocking vaccines induce antibodies in the human blood; when a mosquito takes a blood meal from a protected individual, these antibodies prevent the parasite from completing its development in the mosquito. Other vaccine candidates, targeting the blood-stage of the parasite's life cycle, have been inadequate on their own.

The resulting puppies were all consistent with the inheritance pattern of a yellow Labrador with black pigment. The most probable cause was either a somatic mutation early in development or a fusion between two zygotes that left some cells with genetics capable of producing dark fur, and others including the reproductive cells incapable of doing so. Other “mis-marks” such as brindle, tan points, white spots, and rings around the tails are not uncommon in Labradors. Each of these conditions have various underlying genetic as well as environmental causes.

Triploidy may be the result of either digyny (the extra haploid set is from the mother) or diandry (the extra haploid set is from the father). Diandry is mostly caused by reduplication of the paternal haploid set from a single sperm, but may also be the consequence of dispermic (two sperm) fertilization of the egg. Digyny is most commonly caused by either failure of one meiotic division during oogenesis leading to a diploid oocyte or failure to extrude one polar body from the oocyte. Diandry appears to predominate among early miscarriages, while digyny predominates among triploid zygotes that survive into the fetal period.

Among women who know they are pregnant, the miscarriage rate is roughly 10% to 20%, while rates among all fertilized zygotes are around 30% to 50%. A 2012 review found the risk of miscarriage between 5 and 20 weeks from 11% to 22%. Up to the 13th week of pregnancy, the risk of miscarriage each week was around 2%, dropping to 1% in week 14 and reducing slowly between 14 and 20 weeks. The precise rate is not known because a large number of miscarriages occur before pregnancies become established and before the woman is aware she is pregnant.

In Holoblastic cleavage, the zygote and blastomeres are completely divided during the cleavage, so number of blastomeres doubles with each cleavage.In the absence of a large concentration of yolk, four major cleavage types can be observed in isolecithal cells (cells with a small even distribution of yolk) or in mesolecithal cells or microlecithal cells (moderate amount of yolk in a gradient) – bilateral holoblastic, radial holoblastic, rotational holoblastic, and spiral holoblastic, cleavage. These holoblastic cleavage planes pass all the way through isolecithal zygotes during the process of cytokinesis. Coeloblastula is the next stage of development for eggs that undergo these radial cleavaging.

A chimera virus is defined by the Center for Veterinary Biologics (part of the U.S. Department of Agriculture's Animal and Plant Health Inspection Service) as a "new hybrid microorganism created by joining nucleic acid fragments from two or more different microorganisms in which each of at least two of the fragments contain essential genes necessary for replication." Center for Veterinary Biologics Notice No. 05-23. USDA website. Dec.8, 2005 The term chimera already referred to an individual organism whose body contained cell populations from different zygotes or an organism that developed from portions of different embryos.

Tachibana was educated in Japan, Austria, and the UK. She obtained her PhD working on the cell cycle and cancer formation in the group of Ron Laskey at Cambridge University, UK. She later joined the lab of Kim Nasmyth in Oxford, UK as a post-doc, where she did pioneering work on the role of the protein cohesin in female mouse germ cells. In November 2011 she joined IMBA as a group leader, where she investigates totipotency in mouse oocytes and zygotes as well as the role of maternal aging on egg cell health using mouse as a model system.

Experiments with mice, rats, and dogs have shown that a degree of 25% deuteration causes (sometimes irreversible) sterility, because neither gametes nor zygotes can develop. High concentrations of heavy water (90%) rapidly kill fish, tadpoles, flatworms, and Drosophila. Mammals (for example, rats) given heavy water to drink die after a week, at a time when their body water approaches about 50% deuteration. The mode of death appears to be the same as that in cytotoxic poisoning (such as chemotherapy) or in acute radiation syndrome (though deuterium is not radioactive), and is due to deuterium's action in generally inhibiting cell division.

This occurs as sexual reproduction involves the fusion of two haploid gametes (the egg and sperm) to produce a zygote and a new organism, in which every cell has two sets of chromosomes (diploid). During gametogenesis the normal complement of 46 chromosomes needs to be halved to 23 to ensure that the resulting haploid gamete can join with another haploid gamete to produce a diploid organism. In independent assortment, the chromosomes that result are randomly sorted from all possible maternal and paternal chromosomes. Because zygotes end up with a mix instead of a pre-defined "set" from either parent, chromosomes are therefore considered assorted independently.

For example, when one is planning to use the cell's NHEJ to create a mutation, the cell's HDR systems will also be at work correcting the DSB with lower mutational rates. Traditionally, mice have been the most common choice for researchers as a host of a disease model. CRISPR can help bridge the gap between this model and human clinical trials by creating transgenic disease models in larger animals such as pigs, dogs, and non-human primates. Using the CRISPR-Cas9 system, the programmed Cas9 protein and the sgRNA can be directly introduced into fertilized zygotes to achieve the desired gene modifications when creating transgenic models in rodents.

Adult fraternal twins Dizygotic (DZ) or fraternal twins (also referred to as "non- identical twins", "dissimilar twins", "biovular twins", and, informally in the case of females, "sororal twins") usually occur when two fertilized eggs are implanted in the uterus wall at the same time. When two eggs are independently fertilized by two different sperm cells, fraternal twins result. The two eggs, or ova, form two zygotes, hence the terms dizygotic and biovular. Fraternal twins are, essentially, two ordinary siblings who happen to be born at the same time, since they arise from two separate eggs fertilized by two separate sperm, just like ordinary siblings.

Iliescu was first given hormone treatment to reverse menopause in 1995 and in vitro fertilisation (three zygotes with sperm and ovum from two anonymous donors) in 2004, becoming pregnant with triplets. After ten weeks one of the three fetuses failed to progress and died. The remaining two fetuses, both girls, weighed just 1.45 kilograms (3.19 pounds) and 0.69 kilograms (1.54 pounds) after 33 weeks of pregnancy, but after complications the smaller of the two died in the womb. Though doctors were expecting to perform a caesarian section soon after the 34th week, the death of one of the twins led to the decision to operate earlier than planned.

A rudimentary approach is to introduce an engineered viral vector that contains the optogenetic actuator gene attached to a recognizable promoter such as CAMKIIα. This allows for some level of specificity as cells that already contain and can translate the given promoter will be infected with the viral vector and hopefully express the optogenetic actuator gene. Another approach is the creation of transgenic mice where the optogenetic actuator gene is introduced into mice zygotes with a given promoter, most commonly Thy1. Introduction of the optogenetic actuator at an early stage allows for a larger genetic code to be incorporated and as a result, increases the specificity of cells to be infected.

Hydroid colonies are usually dioecious, which means they have separate sexes—all the polyps in each colony are either male or female, but not usually both sexes in the same colony. In some species, the reproductive polyps, known as gonozooids (or "gonotheca" in thecate hydrozoans) bud off asexually produced medusae. These tiny, new medusae (which are either male or female) mature and spawn, releasing gametes freely into the sea in most cases. Zygotes become free-swimming planula larvae or actinula larvae that either settle on a suitable substrate (in the case of planulae), or swim and develop into another medusa or polyp directly (actinulae).

That imprinting might be a feature of mammalian development was suggested in breeding experiments in mice carrying reciprocal chromosomal translocations. Nucleus transplantation experiments in mouse zygotes in the early 1980s confirmed that normal development requires the contribution of both the maternal and paternal genomes. The vast majority of mouse embryos derived from parthenogenesis (called parthenogenones, with two maternal or egg genomes) and androgenesis (called androgenones, with two paternal or sperm genomes) die at or before the blastocyst/implantation stage. In the rare instances that they develop to postimplantation stages, gynogenetic embryos show better embryonic development relative to placental development, while for androgenones, the reverse is true.

Lazarus tells of his visit as an interplanetary cargo trader to a planet, where he bought a pair of slaves, brother and sister, and immediately manumitted them. Because they had no knowledge of independent living or any education, Lazarus teaches them "how to be human" during the voyage. The two were the result of an experiment in genetic recombination in which two parent cells were separated into complementary haploid gametes and recombined into two embryos. The resulting zygotes were implanted in a woman and gestated by her, with the result that although both have the same surrogate mother and genetic parents, they are no more closely related genetically than any two people taken at random.

Groups like the Association of Libertarian Feminists and Pro-Choice Libertarians support keeping government out of the issue entirely. On the other hand, Libertarians for Life argues that human zygotes, embryos and fetuses possess the same natural human rights and deserve the same protections as neonates, calling for outlawing abortion as an aggressive act against a rights-bearing unborn child. Former Texas Congressman Ron Paul, a figurehead of American libertarianism, is a pro-life physician as is his son Kentucky Senator Rand Paul. Nonetheless, most American libertarians, whether pro-choice or pro-life, agree the federal government should play no role in prohibiting, protecting, or facilitating abortion and oppose the Supreme Court conclusion in Roe v.

After selecting a candidate for the Witchblade among the Neogenes, Furumizu hopes to be reborn from the loins of the designated bearer as a superior being. Following the capture and study of Masane Amaha, he arrogantly believes that he could make a cloneblade more powerful than the original. After realizing that her "grandfather" views her as nothing more than a tool for his rebirth, a radically powerful Neogene named Maria mortally wounds Furumizu in a coup. As Furumizu chokes on his own blood, Nishida informs him that she purposefully neglected to incorporate his genes into the newest batch of Neogene zygotes, as they could not achieve anything more from the continued use of his "flawed" genes.

Offspring of biologically related persons are subject to the possible effects of inbreeding, such as congenital birth defects. The chances of such disorders are increased when the biological parents are more closely related. This is because such pairings have a 25% probability of producing homozygous zygotes, resulting in offspring with two recessive alleles, which can produce disorders when these alleles are deleterious. Because most recessive alleles are rare in populations, it is unlikely that two unrelated marriage partners will both be carriers of the same deleterious allele; however, because close relatives share a large fraction of their alleles, the probability that any such deleterious allele is inherited from the common ancestor through both parents is increased dramatically.

It was found that the release and settlement of eggs and zygotes occurred during daytime low tide periods, particularly when these fell between 10am and 2pm. Few gametes were released during the night time low tide period nor during the daytime period around noon when there was not a low tide. There was no correlation between the temperature or salinity of the water and gamete release and only a weak association with the lunar phase, few gametes being released around the times of full and new moons. The study showed that fertilisation was successful and in the range 80% to 100% in F. distichus due to the avoidance of gamete release when the water velocity is high under the turbulent conditions of high tide.

It is an uncommon syndrome, usually due to some kind of brain injuries in the somatosensory cortex or in some parts of the right hemisphere of the brain, usually due to a stroke in the brain. A chimera is an animal or plant that has two or more different populations of genetically distinct cells that originated in different zygotes that have merged; anatomical structures are typically mixed depending on which cells are prevalent in different body parts, for example plants can have two different types of flowers. A mosaic is a genetic anomaly similar in nature and effects to a chimera: genetically different populations of cells within one organism, originated from some propagated mutation of a single cell rather than from outside sources.

46,XX/46,XY is an exceptionally rare chimeric genetic condition characterized by the presence of some cells that express a 46,XX karyotype and some cells that express a 46,XY karyotype in a single human being. The cause of the condition lies in utero with the aggregation of two distinct blastocysts or zygotes (one of which expresses 46,XX and the other of which expresses 46,XY) into a single embryo, which subsequently leads to the development of a single individual with two distinct cell lines, instead of a pair of fraternal twins. 46,XX/46,XY chimeras are the result of the merging of two non-identical twins. This is not to be confused with mosaicism or hybridism, neither of which are chimeric conditions.

It has since been used in a wide range of organisms, including baker's yeast (Saccharomyces cerevisiae), the opportunistic pathogen Candida albicans, zebrafish (Danio rerio), fruit flies (Drosophila melanogaster), ants (Harpegnathos saltator and Ooceraea biroi), mosquitoes (Aedes aegypti), nematodes (Caenorhabditis elegans), plants, mice, monkeys and human embryos. CRISPR has been modified to make programmable transcription factors that allow scientists to target and activate or silence specific genes. The CRISPR-Cas9 system has shown to make effective gene edits in Human tripronuclear zygotes first described in a 2015 paper by Chinese scientists P. Liang and Y. Xu. The system made a successful cleavage of mutant Beta-Hemoglobin (HBB) in 28 out of 54 embryos. 4 out of the 28 embryos were successfully recombined using a donor template given by the scientists.

Chimeras may also show, under a certain spectrum of UV light, distinctive marks on the back resembling that of arrow points pointing downwards from the shoulders down to the lower back; this is one expression of pigment unevenness called Blaschko's lines. Affected persons may be identified by the finding of two populations of red cells or, if the zygotes are of opposite sex, ambiguous genitalia and intersex alone or in combination; such persons sometimes also have patchy skin, hair, or eye pigmentation (heterochromia). If the blastocysts are of opposite sex, genitals of both sexes may be formed: either ovary and testis, or combined ovotestes, in one rare form of intersex, a condition previously known as true hermaphroditism. Note that the frequency of this condition does not indicate the true prevalence of chimerism.

Here, selection happens at the individual level: those individuals that produce more (but smaller) gametes also gain a larger proportion of fertilizations simply because they produce a larger number of gametes that 'seek out' those of the larger type. However, because zygotes formed from larger gametes have better survival prospects, this process can again lead to the divergence of gametes sizes into large and small (female and male) gametes. The end result is one where it seems that the numerous, small gametes compete for the large gametes that are tasked with providing maximal resources for the offspring. Some recent theoretical work has challenged the gamete competition theory, by showing that gamete limitation by itself can lead to the divergence of gamete sizes even under selection at the individual level.

For each homozygous recessive individual formed there is an equal chance of producing a homozygous dominant individual — one completely devoid of the harmful allele. Contrary to common belief, inbreeding does not in itself alter allele frequencies, but rather increases the relative proportion of homozygotes to heterozygotes; however, because the increased proportion of deleterious homozygotes exposes the allele to natural selection, in the long run its frequency decreases more rapidly in inbred populations. In the short term, incestuous reproduction is expected to increase the number of spontaneous abortions of zygotes, perinatal deaths, and postnatal offspring with birth defects. The advantages of inbreeding may be the result of a tendency to preserve the structures of alleles interacting at different loci that have been adapted together by a common selective history.

Adult male and female medusa spawn daily, and can be entrained with controlled light conditions to spawn at specific times. The oocytes, eggs, embryos, and planulae of Clytia are easily visualized under a microscope and, much like those of popular model organisms like sea urchins, the zygotes of C. hemisphaerica are relatively large (around 200 um in diameter) and can be microinjected to form transgenic planulae, polyp colonies, and medusa. Clytia is also unique in that its gonads can function autonomously; a gonad separated from an adult medusa will undergo oocyte development and ovulation under the same entrained light cues as would a gonad still attached to a medusa. Clytia medusa that are produced from a single polyp colony are also genetically identical, presenting a huge advantage for gene function analysis as well as genome sequencing.

The NAWJ became a co-sponsor to the National Judicial Education Program to Promote Equality for Women and Men in the Courts (NJEP) program launched in 1980 by the National Organization of Women's Legal Defense and Education Fund, now known as Legal Momentum. The NJEP works to promote equality in the judicial system through education, publications, and supporting the efforts of gender bias task forces in courts across the country. NJEP's educational programming is used widely across the country in both print and video format for lawyers, judges, and other professionals alike, focusing on unique issues women face in both criminal and civil cases and other ways women are impacted in the judiciary. As part of the NJEP, these organizations have published Gender, Justice and Law: From Asylum to Zygotes - Issues and Resources for Judicial, Legal and Continuing Legal Education, a 500-page book covering over 60 topics regarding the relationship between the legal system and gender bias.

It is also made clear that, at the time of their deaths, all the civil servants were aged around 65 and had cold, domineering and abusive attitudes toward their adopted sons, while their wives were around 42 and doted on the sons. Lieberman gains insight from Frieda Maloney (Uta Hagen), an incarcerated former Nazi concentration-camp guard who worked with the adoption agency, before realising during a meeting with Professor Bruckner (Bruno Ganz), an expert on cloning, the terrible truth behind the Nazi plan: Mengele, in the 1960s, had secluded several surrogate mothers in a Brazilian clinic and implanted them with zygotes each carrying a sample of Adolf Hitler's DNA preserved since the Second World War. 94 clones of Hitler had then been born and sent to different parts of the world for adoption. In the hopes that one or more of the boys will turn out like the original Hitler, Mengele has arranged for all of them to be placed with foster parents similar to Hitler's own, and is assassinating their foster fathers at the same age at which Hitler's own died.