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:The small noncoding RNAs (sncRNAs) are considered as post-transcriptional 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 sncRNA populations detected at three milestone stages in male germ differentiation: primordial germ cells (PGCs), pubertal spermatogonia cells, and mature spermatozoa. To assess their potential transmission through the spermatozoa during fertilization, the sncRNAs of mouse oocytes and zygotes were also analyzed. Both, microRNAs and snoRNA-derived small RNAs are abundantly expressed in PGCs but transiently replaced by piRNAs in spermatozoa and endo-siRNAs in oocytes and zygotes. Exhaustive analysis of miRNA sequence variants also shows an increment of noncanonical microRNA forms along male germ cell differentiation. RNAs-derived from tRNAs and rRNAs interacting with PIWI proteins are not generated by the ping-pong pathway and could be a source of primary piRNAs. Moreover, our results strongly suggest that the small RNAs-derived from tRNAs and rRNAs are interacting with PIWI proteins, and specifically with MILI. Finally, computational analysis revealed their potential involvement in post-transcriptional regulation of mRNA transcripts suggesting functional convergence among different small RNA classes in germ cells 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. 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:BACKGROUND: Marine diatoms constitute a major component of eukaryotic phytoplankton and stand at the crossroads of several evolutionary lineages. These microalgae possess peculiar genomic features and novel combinations of genes acquired from bacterial, animal and plant ancestors. Furthermore, they display both DNA methylation and gene silencing activities. Yet, the biogenesis and regulatory function of small RNAs (sRNAs) remain ill defined in diatoms. RESULTS: Here we report the first comprehensive characterization of the sRNA landscape and its correlation with genomic and epigenomic information in Phaeodactylum tricornutum. The majority of sRNAs is 25 to 30 nt-long and maps to repetitive and silenced Transposable Elements marked by DNA methylation. A subset of this population also targets DNA methylated protein-coding genes, suggesting that gene body methylation might be sRNA-driven in diatoms. Remarkably, 25-30 nt sRNAs display a well-defined and unprecedented 180 nt-long periodic distribution at several highly methylated regions that awaits characterization. While canonical miRNAs are not detectable, other 21-25 nt sRNAs of unknown origin are highly expressed. Besides, non-coding RNAs with well-described function, namely tRNAs and U2 snRNA, constitute a major source of 21-25 nt sRNAs and likely play important roles under stressful environmental conditions. CONCLUSIONS: P. tricornutum has evolved diversified sRNA pathways, likely implicated in the regulation of largely still uncharacterized genetic and epigenetic processes. These results uncover an unexpected complexity of diatom sRNA population and previously unappreciated features, providing new insights into the diversification of sRNA-based processes in eukaryotes.
Project description:Spermatogenic failure is a major cause of male infertility, which affects millions of couples worldwide. Recent discovery of long non-coding RNAs (lncRNAs) as critical regulators in normal and disease development provides new clues for delineating the molecular regulation in male germ cell development. However, few functional lncRNAs have been characterized to date. A major limitation in studying lncRNA in male germ cell development is the absence of germ cell-specific lncRNA annotation. Current lncRNA annotations are assembled by transcriptome data from heterogeneous tissue sources; specific germ cell transcript information of various developmental stages is therefore under-represented, which may lead to biased prediction or fail to identity important germ cell-specific lncRNAs. GermlncRNA provides the first comprehensive web-based and open-access lncRNA catalogue for three key male germ cell stages, including type A spermatogonia, pachytene spermatocytes and round spermatids. This information has been developed by integrating male germ transcriptome resources derived from RNA-Seq, tiling microarray and GermSAGE. Characterizations on lncRNA-associated regulatory features, potential coding gene and microRNA targets are also provided. Search results from GermlncRNA can be exported to Galaxy for downstream analysis or downloaded locally. Taken together, GermlncRNA offers a new avenue to better understand the role of lncRNAs and associated targets during spermatogenesis. Database URL: http://germlncrna.cbiit.cuhk.edu.hk/
Project description:Small non-coding RNAs (sncRNAs) are indispensable for proper germ cell development, emphasizing the need for greater elucidation of the mechanisms of germline development and regulation of this process by sncRNAs. We used deep sequencing to characterize three families of small non-coding RNAs (piRNAs, miRNAs, and tRFs) present in Sus scrofa gonads and focused on the small RNA fraction present in both male and female gonads. Although similar numbers of reads were obtained from both types of gonads, the number of unique RNA sequences in the ovaries was several times lower. Of the sequences detected in the testes, 2.6% of piRNAs, 9% of miRNAs, and 10% of tRFs were also present in the ovaries. Notably, the majority of the shared piRNAs mapped to ribosomal RNAs and were derived from clustered loci. In addition, the most abundant miRNAs present in the ovaries and testes are conserved and are involved in many biological processes such as the regulation of homeobox genes, the control of cell proliferation, and carcinogenesis. Unexpectedly, we detected a novel sncRNA type, the tRFs, which are 30-36-nt RNA fragments derived from tRNA molecules, in gonads. Analysis of S. scrofa piRNAs show that testes specific piRNAs are biased for 5' uracil but both testes and ovaries specific piRNAs are not biased for adenine at the 10th nucleotide position. These observations indicate that adult porcine piRNAs are predominantly produced by a primary processing pathway or other mechanisms and secondary piRNAs generated by ping-pong mechanism are absent.
Project description:Small non-coding RNAs (sRNAs) are active in many bacterial cell functions, including regulation of the cell's response to environmental challenges. We describe the identification of 27 novel Caulobacter crescentus sRNAs by analysis of RNA expression levels assayed using a tiled Caulobacter microarray and a protocol optimized for detection of sRNAs. The principal analysis method involved identification of sets of adjacent probes with unusually high correlation between the individual intergenic probes within the set, suggesting presence of a sRNA. Among the validated sRNAs, two are candidate transposase gene antisense RNAs. The expression of 10 of the sRNAs is regulated by either entry into stationary phase, carbon starvation, or rich versus minimal media. The expression of four of the novel sRNAs changes as the cell cycle progresses. One of these shares a promoter motif with several genes expressed at the swarmer-to-stalked cell transition; while another appears to be controlled by the CtrA global transcriptional regulator. The probe correlation analysis approach reported here is of general use for large-scale sRNA identification for any sequenced microbial genome.