Topic
Germ plasm
About: Germ plasm is a research topic. Over the lifetime, 1130 publications have been published within this topic receiving 60840 citations.
Papers published on a yearly basis
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Papers
TL;DR: It is shown that Blimp1 (also known as Prdm1), a known transcriptional repressor, has a critical role in the foundation of the mouse germ cell lineage, as its disruption causes a block early in the process of primordial germ cell formation.
Abstract: Germ cell fate in mice is induced in pluripotent epiblast cells in response to signals from extraembryonic tissues. The specification of approximately 40 founder primordial germ cells and their segregation from somatic neighbours are important events in early development. We have proposed that a critical event during this specification includes repression of a somatic programme that is adopted by neighbouring cells. Here we show that Blimp1 (also known as Prdm1), a known transcriptional repressor, has a critical role in the foundation of the mouse germ cell lineage, as its disruption causes a block early in the process of primordial germ cell formation. Blimp1-deficient mutant embryos form a tight cluster of about 20 primordial germ cell-like cells, which fail to show the characteristic migration, proliferation and consistent repression of homeobox genes that normally accompany specification of primordial germ cells. Furthermore, our genetic lineage-tracing experiments indicate that the Blimp1-positive cells originating from the proximal posterior epiblast cells are indeed the lineage-restricted primordial germ cell precursors.
1,097 citations
TL;DR: It is found that retinoic acid, produced by mesonephroi of both sexes, causes germ cells in the ovary to enter meiosis and inititate oogenesis, and precise regulation of retinoid levels during fetal gonad development provides the molecular control mechanism that specifies germ cell fate.
Abstract: Germ cells in the mouse embryo can develop as oocytes or spermatogonia, depending on molecular cues that have not been identified. We found that retinoic acid, produced by mesonephroi of both sexes, causes germ cells in the ovary to enter meiosis and inititate oogenesis. Meiosis is retarded in the fetal testis by the action of the retinoid-degrading enzyme CYP26B1, ultimately leading to spermatogenesis. In testes of Cyp26b1-knockout mouse embryos, germ cells enter meiosis precociously, as if in a normal ovary. Thus, precise regulation of retinoid levels during fetal gonad development provides the molecular control mechanism that specifies germ cell fate.
1,043 citations
TL;DR: It is shown that embryoid bodies support maturation of the primordial germ cells into haploid male gametes, which when injected into oocytes restore the somatic diploid chromosome complement and develop into blastocysts.
Abstract: Egg and sperm cells (gametes) of the mouse are derived from a founder population of primordial germ cells that are set aside early in embryogenesis. Primordial germ cells arise from the proximal epiblast, a region of the early mouse embryo that also contributes to the first blood lineages of the embryonic yolk sac. Embryonic stem cells differentiate in vitro into cystic structures called embryoid bodies consisting of tissue lineages typical of the early mouse embryo. Because embryoid bodies sustain blood development, we reasoned that they might also support primordial germ cell formation. Here we isolate primordial germ cells from embryoid bodies, and derive continuously growing lines of embryonic germ cells. Embryonic germ cells show erasure of the methylation markers (imprints) of the Igf2r and H19 genes, a property characteristic of the germ lineage. We show that embryoid bodies support maturation of the primordial germ cells into haploid male gametes, which when injected into oocytes restore the somatic diploid chromosome complement and develop into blastocysts. Our ability to derive germ cells from embryonic stem cells provides an accessible in vitro model system for studies of germline epigenetic modification and mammalian gametogenesis.
967 citations
TL;DR: It is shown that fragilis, an interferon-inducible transmembrane protein, marks the onset of germ cell competence, and it is proposed that through homotypic association, it demarcates germ cells from somatic neighbours.
Abstract: Germ cell fate in mice is induced in proximal epiblast cells by the extra-embryonic ectoderm, and is not acquired through the inheritance of any preformed germ plasm. To determine precisely how germ cells are specified, we performed a genetic screen between single nascent germ cells and their somatic neighbours that share common ancestry. Here we show that fragilis, an interferon-inducible transmembrane protein, marks the onset of germ cell competence, and we propose that through homotypic association, it demarcates germ cells from somatic neighbours. Using single-cell gene expression profiles, we also show that only those cells with the highest expression of fragilis subsequently express stella, a gene that we detected exclusively in lineage-restricted germ cells. The stella positive nascent germ cells exhibit repression of homeobox genes, which may explain their escape from a somatic cell fate and the retention of pluripotency.
945 citations
TL;DR: It is shown that oskar RNA is localized to the posterior pole of the oocyte when germ plasm forms and proposed that the pole plasm is assembled stepwise and that continued interaction among its components is required for germ cell determination.
870 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 10 |
| 2024 | 12 |
| 2023 | 12 |
| 2022 | 39 |
| 2021 | 20 |
| 2020 | 16 |