Project description:Functional diversity and convergence of small non-coding RNAs in male germ cell differentiation and fertilization (piRNA and endo-siRNAs)
Project description:The small non-coding RNAs (sncRNAs) are considered as postranscriptional key regulators of male germ cell development. In addition to microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs), other sncRNAs generated from small nucleolar RNAs (snoRNAs), tRNAs or rRNAs processing may also play important regulatory roles in spermatogenesis. By next generation sequencing (NGS), we characterized the different sncRNA populations detected at three milestone stages in male germ differentiation: primordial germ cells (PGCs) at 13.5 dpc, pubertal spermatogonia cells, and mature spermatozoa. In order to assess the potential transmission of the sncRNAs through the mature spermatozoa during fertilization, the sncRNA population detected in male germ cells was also compared with sncRNAs detected in unfertilized mouse oocytes and zygotes. Combining the data obtained by NGS and microarrays from whole PGC and spermatogonia transcriptome, we defined the potential regulatory roles of specific miRNAs and their validated targets. Similar to miRNAs, both the small RNAs derived from snoRNAs and the piRNAs, could be involved in the postranscriptional regulation of mRNA transcripts during the male germ development. Finally, our results strongly suggest that the small RNAs-derived from tRNAs and rRNAs are interacting with PIWI proteins, and specifically with MILI. These new classes of piRNAs are not generated by the ping-pong pathway and could be the source of primary piRNAs. Comparative analysis from deep sequencing of piRNAs and endo-siRNAs in mouse oocytes, spermatozoa and zygotes
Project description:The small non-coding RNAs (sncRNAs) are considered as postranscriptional key regulators of male germ cell development. In addition to microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs), other sncRNAs generated from small nucleolar RNAs (snoRNAs), tRNAs or rRNAs processing may also play important regulatory roles in spermatogenesis. By next generation sequencing (NGS), we characterized the different sncRNA populations detected at three milestone stages in male germ differentiation: primordial germ cells (PGCs) at 13.5 dpc, pubertal spermatogonia cells, and mature spermatozoa. In order to assess the potential transmission of the sncRNAs through the mature spermatozoa during fertilization, the sncRNA population detected in male germ cells was also compared with sncRNAs detected in unfertilized mouse oocytes and zygotes. Combining the data obtained by NGS and microarrays from whole PGC and spermatogonia transcriptome, we defined the potential regulatory roles of specific miRNAs and their validated targets. Similar to miRNAs, both the small RNAs derived from snoRNAs and the piRNAs, could be involved in the postranscriptional regulation of mRNA transcripts during the male germ development. Finally, our results strongly suggest that the small RNAs-derived from tRNAs and rRNAs are interacting with PIWI proteins, and specifically with MILI. These new classes of piRNAs are not generated by the ping-pong pathway and could be the source of primary piRNAs.
Project description:The small non-coding RNAs (sncRNAs) are considered as postranscriptional key regulators of male germ cell development. In addition to microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs), other sncRNAs generated from small nucleolar RNAs (snoRNAs), tRNAs or rRNAs processing may also play important regulatory roles in spermatogenesis. By next generation sequencing (NGS), we characterized the different sncRNA populations detected at three milestone stages in male germ differentiation: primordial germ cells (PGCs) at 13.5 dpc, pubertal spermatogonia cells, and mature spermatozoa. In order to assess the potential transmission of the sncRNAs through the mature spermatozoa during fertilization, the sncRNA population detected in male germ cells was also compared with sncRNAs detected in unfertilized mouse oocytes and zygotes. Combining the data obtained by NGS and microarrays from whole PGC and spermatogonia transcriptome, we defined the potential regulatory roles of specific miRNAs and their validated targets. Similar to miRNAs, both the small RNAs derived from snoRNAs and the piRNAs, could be involved in the postranscriptional regulation of mRNA transcripts during the male germ development. Finally, our results strongly suggest that the small RNAs-derived from tRNAs and rRNAs are interacting with PIWI proteins, and specifically with MILI. These new classes of piRNAs are not generated by the ping-pong pathway and could be the source of primary piRNAs.
Project description:The small non-coding RNAs (sncRNAs) are considered as postranscriptional key regulators of male germ cell development. In addition to microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs), other sncRNAs generated from small nucleolar RNAs (snoRNAs), tRNAs or rRNAs processing may also play important regulatory roles in spermatogenesis. By next generation sequencing (NGS), we characterized the different sncRNA populations detected at three milestone stages in male germ differentiation: primordial germ cells (PGCs) at 13.5 dpc, pubertal spermatogonia cells, and mature spermatozoa. In order to assess the potential transmission of the sncRNAs through the mature spermatozoa during fertilization, the sncRNA population detected in male germ cells was also compared with sncRNAs detected in unfertilized mouse oocytes and zygotes. Combining the data obtained by NGS and microarrays from whole PGC and spermatogonia transcriptome, we defined the potential regulatory roles of specific miRNAs and their validated targets. Similar to miRNAs, both the small RNAs derived from snoRNAs and the piRNAs, could be involved in the postranscriptional regulation of mRNA transcripts during the male germ development. Finally, our results strongly suggest that the small RNAs-derived from tRNAs and rRNAs are interacting with PIWI proteins, and specifically with MILI. These new classes of piRNAs are not generated by the ping-pong pathway and could be the source of primary piRNAs. mRNA analysis of Primordial Germ Cells (PGCs), Spermatogonia cells (SPG), adult testis (AdT) and Gonad-less (GL) embryos. Indirect comparisons were made across multiple arrays with raw data pulled from different channels for data analysis and comparison to the control data.
Project description:DICER has a well-characterized role in the processing of microRNAs (miRNAs) and small interfering RNAs (siRNA) that are important for post-transcriptional gene regulation. Emerging evidence suggests that DICER also has several non-canonical functions beyond miRNA/siRNA biogenesis, for example in transcriptional gene silencing at the chromatin level, as well as in RNA degradation and maintenance of genomic integrity. We have shown that the function of DICER in germ cells is essential for normal spermatogenesis; male mice lacking DICER in postnatal male germ cells are infertile due to severe defects in haploid differentiation. To better understand the function of DICER in male germ cells, we immunoprecipitated DICER from juvenile mouse testes and performed mass spectrometric analysis to identify DICER-interacting proteins.
Project description:The genome of male germ cells is actively transcribed during spermatogenesis to produce phase-specific protein coding mRNAs and a considerable amount of different non-coding RNAs. Ribonucleoprotein (RNP) granule-mediated RNA regulation provides a powerful means to secure the quality and correct expression of the requisite transcripts. Haploid spermatids are characterized by a unique, unusually large cytoplasmic granule, the chromatoid body (CB), that emerges during the switch between the meiotic and post-meiotic phases of spermatogenesis. To better understand the role of the CB in male germ cell differentiation, we isolated CBs from mouse testes and revealed its full RNA and protein composition. We showed that the CB is mainly composed of RNA-binding proteins and other proteins involved RNA regulation. The CB was loaded with RNA, including pachytene piRNAs, a diverse set of mRNAs and a number of uncharacterized long non-coding transcripts. The CB was demonstrated to accumulate nascent RNA during all the steps of round spermatid differentiation. Our results revealed the CB as a large germ cell -specific RNP platform that is involved in the control of the highly complex transcriptome of haploid male germ cells. Small RNA profiling of purified chromatoid body, each steps of chromatoid body purification, and sortred round spermatid cells
Project description:Spermatogenesis is a complex process, dependent upon the successive activation and/or repression of thousands of gene products, and ends with the production of haploid male gametes. RNA sequencing of male germ cells in the rat identified thousands of novel testicular unannotated transcripts, named TUTs. Although such RNAs are usually annotated as long non-coding RNAs, it is possible that some of these TUTs code for protein. To test this possibility, we used a “Proteomics Informed by Transcriptomics” strategy, combining shotgun proteomics analyses and RNA sequencing data for enriched populations of rat testicular cells. Among 3559 TUTs and 506 lncRNAs found in meiotic and post-meiotic germ cells, 44 encoded at least one peptide. We show that these novel high-confidence protein-coding loci exhibit several genomic features intermediate between those of lncRNAs and mRNAs. We experimentally validated the testicular expression pattern of two of these novel protein-coding gene candidates, both highly conserved in mammals: one for a vesicle-associated membrane protein, we named VAMP-9, and the other for an enolase domain-containing protein. This study confirms the potential of PIT approaches for the discovery of protein coding transcripts initially thought to be untranslated, or unknown transcripts. Our results contribute to the understanding of spermatogenesis by characterizing two novel proteins, implicated by their strong expression in germ cells.
Project description:The genome of male germ cells is actively transcribed during spermatogenesis to produce phase-specific protein coding mRNAs and a considerable amount of different non-coding RNAs. Ribonucleoprotein (RNP) granule-mediated RNA regulation provides a powerful means to secure the quality and correct expression of the requisite transcripts. Haploid spermatids are characterized by a unique, unusually large cytoplasmic granule, the chromatoid body (CB), that emerges during the switch between the meiotic and post-meiotic phases of spermatogenesis. To better understand the role of the CB in male germ cell differentiation, we isolated CBs from mouse testes and revealed its full RNA and protein composition. We showed that the CB is mainly composed of RNA-binding proteins and other proteins involved RNA regulation. The CB was loaded with RNA, including pachytene piRNAs, a diverse set of mRNAs and a number of uncharacterized long non-coding transcripts. The CB was demonstrated to accumulate nascent RNA during all the steps of round spermatid differentiation. Our results revealed the CB as a large germ cell-specific RNP platform that is involved in the control of the highly complex transcriptome of haploid male germ cells. Transcriptome profling of purified chromatoid body, each steps of chromatoid body purification, and sortred round spermatid cells