At the beginning of meiosis i, a female wallaby germ cells contains choose 1 answer:
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. 2021 Mar;161(3):333-341. Show
doi: 10.1530/REP-20-0634. Affiliations
Male germline development in the tammar wallaby, Macropus eugeniiTeruhito Ishihara et al. Reproduction. 2021 Mar. AbstractMale germ cells undergo two consecutive processes - pre-spermatogenesis and spermatogenesis - to generate mature sperm. In eutherian mammals, epigenetic information such as DNA methylation is dynamically reprogrammed during pre-spermatogenesis, before and during mitotic arrest. In mice, by the time germ cells resume mitosis, the majority of DNA methylation is reprogrammed. The tammar wallaby has a similar pattern of germ cell global DNA methylation reprogramming to that of the mouse during early pre-spermatogenesis. However, early male germline development in the tammar or in any marsupial has not been described previously, so it is unknown whether this is a general feature regulating male germline development or a more recent phenomenon in mammalian evolutionary history. To answer this, we examined germ cell nuclear morphology and mitotic arrest during male germline development in the tammar wallaby (Macropus eugenii), a marsupial that diverged from mice and humans around 160 million years ago. Tammar pro-spermatogonia proliferated after birth and entered mitotic arrest after day 30 postpartum (pp). At this time, they began moving towards the periphery of the testis cords and their nuclear size increased. Germ cells increased in number after day 100 pp which is the time that DNA methylation is known to be re-established in the tammar. This is similar to the pattern observed in the mouse, suggesting that resumption of germ cell mitosis and the timing of DNA methylation reprogramming are correlated and conserved across mammals and over long evolutionary timescales. Similar articles
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What are the products of meiosis in females?Meiosis is a conserved cell division process that is used by sexually reproducing organisms to generate haploid gametes. Males and females produce different end products of meiosis: eggs (females) and sperm (males).
Which happens during meiosis 1?In meiosis I, chromosomes in a diploid cell resegregate, producing four haploid daughter cells. It is this step in meiosis that generates genetic diversity. DNA replication precedes the start of meiosis I. During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis.
What does meiosis result in in females?Meiosis in human females produces one large egg cell that has nearly all of the cytoplasm of the parent cell. The other cells produced by female meiosis are called "polar bodies". These are very small cells that have little more than the extra homologous chromosomes and chromatids not needed by the egg cell.
In which cell does meiosis 1 occur?Meiosis I is a unique cell division that occurs only in germ cells; meiosis II is similar to a mitotic division. Before germ cells enter meiosis, they are generally diploid, meaning that they have two homologous copies of each chromosome.
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