Germ cell sexual differentiation requires Nanos2-mediated repression of Dazl in mice
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE56795 | GEO | 2015/12/01
SECONDARY ACCESSION(S): PRJNA244618
REPOSITORIES: GEO
Similar Datasets
Project description:In mouse embryos, sex-specific differentiation of primordial germ cells (PGCs) begins with distinct cell cycle regulations: while PGCs in female (XX) gonads enter meiosis, PGCs in male (XY) gonads defer meiosis and arrest cell cycle1,2. The mitotic quiescence in XY gonads requires Nanos2, an evolutionarily conserved RNA-binding protein implicated in RNA degradation3-5; however, underlying mechanisms including the identity of its target mRNAs in vivo remain unknown. Here we show that Nanos2 negatively regulates Dazl (Deleted in azoospermia-like), a germline-specific gene encoding an RNA-binding protein that is implicated in translational control and meiotic initiation6,7. Comprehensive microarray analyses identified Dazl as one of the genes that were up-regulated in Nanos2-deficient XY gonads, but down-regulated in Nanos2-expressing XX gonads. Analysis of a BAC transgenic mouse line, in which the 3’UTR of Dazl can be removed by Flp-Frt recombination system, showed that repression of Dazl is likely achieved by the association of Nanos2 with Dazl’s 3’UTR. Elevated levels of Dazl expression in the transgenic XY PGCs resulted in abnormal progression of cell cycles including meiosis, reminiscent of the phenotype observed in Nanos2-/- XY gonads. This phenotype was suppressed by inhibiting retinoic acid (RA) signaling, suggesting that Nanos2 represses Dazl to prevent RA-induced cell cycle progression in XY PGCs. Furthermore, we show that a part of Nanos2-associated mRNAs, most of which are up-regulated in Nanos2-/- XY gonads, can also associate with Dazl, and that excess Dazl impedes localization of Nanos2 to processing-bodies where RNA degradation takes place, suggesting that repression of Dazl is required for Nanos2 to efficiently degrade its target mRNAs. These data provide the first link between the two RNA-binding proteins that play pivotal roles in sexual differentiation of murine PGCs.
2015-12-01 | GSE56794 | GEO
Project description:In mouse embryos, sex-specific differentiation of primordial germ cells (PGCs) begins with distinct cell cycle regulations: while PGCs in female (XX) gonads enter meiosis, PGCs in male (XY) gonads defer meiosis and arrest cell cycle1,2. The mitotic quiescence in XY gonads requires Nanos2, an evolutionarily conserved RNA-binding protein implicated in RNA degradation3-5; however, underlying mechanisms including the identity of its target mRNAs in vivo remain unknown. Here we show that Nanos2 negatively regulates Dazl (Deleted in azoospermia-like), a germline-specific gene encoding an RNA-binding protein that is implicated in translational control and meiotic initiation6,7. Comprehensive microarray analyses identified Dazl as one of the genes that were up-regulated in Nanos2-deficient XY gonads, but down-regulated in Nanos2-expressing XX gonads. Analysis of a BAC transgenic mouse line, in which the 3’UTR of Dazl can be removed by Flp-Frt recombination system, showed that repression of Dazl is likely achieved by the association of Nanos2 with Dazl’s 3’UTR. Elevated levels of Dazl expression in the transgenic XY PGCs resulted in abnormal progression of cell cycles including meiosis, reminiscent of the phenotype observed in Nanos2-/- XY gonads. This phenotype was suppressed by inhibiting retinoic acid (RA) signaling, suggesting that Nanos2 represses Dazl to prevent RA-induced cell cycle progression in XY PGCs. Furthermore, we show that a part of Nanos2-associated mRNAs, most of which are up-regulated in Nanos2-/- XY gonads, can also associate with Dazl, and that excess Dazl impedes localization of Nanos2 to processing-bodies where RNA degradation takes place, suggesting that repression of Dazl is required for Nanos2 to efficiently degrade its target mRNAs. These data provide the first link between the two RNA-binding proteins that play pivotal roles in sexual differentiation of murine PGCs.
2015-12-01 | GSE56793 | GEO
Project description:Germ cell sexual differentiation requires Nanos2-mediated repression of Dazl in mice
| PRJNA244618 | ENA
Project description:Evolutionally conserved Nanos RNA-binding proteins play crucial roles in germ cell development. While a mammalian Nanos family protein, NANOS2, is required for sexual differentiation of male (XY) germ cells in mice, the underlying mechanisms and the identities of its target RNAs in vivo remain elusive. Using comprehensive microarray analysis and a bacterial artificial chromosome transgenic system, here we identify Dazl, a germ cell-specific gene encoding an RNA-binding protein implicated in translation, as a crucial target of NANOS2. Importantly, removal of the Dazl 3'-untranslated region in XY germ cells stabilizes the Dazl mRNA, resulting in elevated meiotic gene expression, abnormal resumption of the cell cycle and impaired processing-body formation, reminiscent of Nanos2-knockout phenotypes. Furthermore, our data suggest that NANOS2 acts as an antagonist of the DAZL protein. We propose a dual system of NANOS2-mediated suppression of Dazl expression as a pivotal molecular mechanism promoting sexual differentiation of XY germ cells.
| S-EPMC4833867 | biostudies-other
Project description:Mammalian oocytes and spermatozoa derive from fetal cells shared by the sexes. These primordial germ cells (PGCs) migrate to the developing somatic gonad, giving rise to oocytes or spermatozoa. These opposing sexual fates are determined not by the PGCs' own sex chromosome constitution (XX or XY), but by the sexual identity of the fetal gonad that they enter. We asked whether PGCs undergo a developmental transition that enables them to respond to feminizing or masculinizing cues from fetal ovary or testis. We conducted in vivo genetic studies of DAZL, an RNA-binding protein expressed in both ovarian and testicular germ cells. We found that germ cells in C57BL/6 Dazl--deficient fetuses-whether XX or XY--migrate to the gonad but do not develop either male or female features. Instead, they remain in a sexually undifferentiated state similar to that of migrating PGCs. Thus, germ cells in C57BL/6 Dazl-deficient fetuses do not respond to sexual cues from ovary or testis, whereas the earlier processes of germ cell specification and migration are unaffected. We propose that PGCs of both XX and XY fetuses undergo licensing, an active developmental transition that enables the resultant gametogenesis-competent cells to respond to feminizing or masculinizing cues produced by the fetal ovary or testis and hence to embark on oogenesis or spermatogenesis. In C57BL/6 mice, Dazl is required for licensing. Licensing serves as a gateway from the embryonic processes shared between the sexes--germ cell specification and migration--to the sex-specific pathways of oogenesis and spermatogenesis.
| S-EPMC3088606 | biostudies-literature
Project description:The scarcity of primordial germ cells (PGCs) in the developing mammalian embryo hampers robust biochemical analysis of the processes that underlie early germ cell formation. Here, we demonstrate that DAZL, a germ cell-specific RNA binding protein, is a robust PGC marker during in vitro germ cell development. Using Dazl-GFP reporter ESCs, we demonstrate that DAZL plays a central role in a large mRNA/protein interactive network that blocks the translation of core pluripotency factors, including Sox2 and Sall4, as well as of Suz12, a polycomb family member required for differentiation of pluripotent cells. Thus, DAZL limits both pluripotency and somatic differentiation in nascent PGCs. In addition, we observed that DAZL associates with mRNAs of key Caspases and similarly inhibits their translation. This elegant fail-safe mechanism ensures that, whereas loss of DAZL results in prolonged expression of pluripotency factors, teratoma formation is avoided due to the concomitant activation of the apoptotic cascade.
| S-EPMC4235140 | biostudies-literature
Project description:BackgroundDuring zebrafish embryogenesis, microRNA (miRNA) miR-430 contributes to restrict Nanos1 and TDRD7 to primordial germ cells (PGCs) by inducing mRNA deadenylation, mRNA degradation, and translational repression of nanos1 and tdrd7 mRNAs in somatic cells. The nanos1 and tdrd7 3'UTRs include cis-acting elements that allow activity in PGCs even in the presence of miRNA-mediated repression.Methodology/principal findingsUsing a GFP reporter mRNA that was fused with tdrd7 3'UTR, we show that a germline-specific RNA-binding protein DAZ-like (DAZL) can relieve the miR-430-mediated repression of tdrd7 mRNA by inducing poly(A) tail elongation (polyadenylation) in zebrafish. We also show that DAZL enhances protein synthesis via the 3'UTR of dazl mRNA, another germline mRNA targeted by miR-430.Conclusions/significanceOur present study indicated that DAZL acts as an "anti-miRNA factor" during vertebrate germ cell development. Our data also suggested that miRNA-mediated regulation can be modulated on specific target mRNAs through the poly(A) tail control.
| S-EPMC2759513 | biostudies-literature
Project description:In many animal models, primordial germ cell (PGC) development depends on maternally deposited germ plasm, which prevents somatic cell fate. Here, we show that PGCs respond to regulatory information from the germ plasm in two distinct phases using two distinct mechanisms in zebrafish. We demonstrate that PGCs commence zygotic genome activation together with the somatic blastocysts with no demonstrable differences in transcriptional and chromatin opening. Unexpectedly, both PGC and somatic blastocysts activate germ-cell-specific genes, which are only stabilized in PGCs by cytoplasmic germ plasm determinants. Disaggregated perinuclear relocalization of germ plasm during PGC migration is regulated by the germ plasm determinant Tdrd7 and is coupled to dramatic divergence between PGC and somatic transcriptomes. This transcriptional divergence relies on PGC-specific cis-regulatory elements characterized by promoter-proximal distribution. We show that Tdrd7-dependent reconfiguration of chromatin accessibility is required for elaboration of PGC fate but not for PGC migration.
| S-EPMC7957325 | biostudies-literature
Project description:RNA-binding Fox (Rbfox) proteins have well-established roles in regulating alternative splicing, but specific Rbfox isoforms lack nuclear localization signals and accumulate in the cytoplasm. The potential splicing-independent functions of these proteins remain unknown. Here we demonstrate that cytoplasmic Drosophila Rbfox1 regulates germ cell development and represses the translation of mRNAs containing (U)GCAUG elements within their 3'UTRs. During germline cyst differentiation, Rbfox1 targets pumilio mRNA for destabilization and translational silencing, thereby promoting germ cell development. Mis-expression of pumilio results in the formation of germline tumors, which contain cysts that break down and dedifferentiate back to single, mitotically active cells. Together, these results reveal that cytoplasmic Rbfox family members regulate the translation of specific target mRNAs. In the Drosophila ovary, this activity provides a genetic barrier that prevents germ cells from reverting back to an earlier developmental state. The finding that Rbfox proteins regulate mRNA translation has implications for Rbfox-related diseases.
| S-EPMC4785839 | biostudies-literature
Project description:In embryonic male germ cells, the RNA-binding protein NANOS2 recruits its target RNAs to processing bodies (P-bodies), where they are repressed. This process is necessary to promote male-type germ cell differentiation. However, it remains unclear whether all NANOS2 functions depend on P-bodies. To address this question, we established ES cell lines containing a germ cell-specific inducible Cre and reporter together with the floxed Ddx6 allele. We deleted the Ddx6 gene by administering tamoxifen to chimeric embryos containing germ cells derived from recombinant ES cells. DDX6-null germ cells exhibited both similar and distinct defects from those observed in NANOS2-null germ cells. These results demonstrate that NANOS2 function is carried out via both P-body-dependent and -independent mechanisms. RNA-seq analyses further supported the phenotypic differences between DDX6-null and NANOS2-null germ cells, and indicated distinct molecular cascades involved in NANOS2-mediated gene regulation.
| S-EPMC6345806 | biostudies-other