title: Diversity and functional convergence of small noncoding RNAs in male germ cell differentiation and fertilization.
abstract: 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.
authors: Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain.
authors: Jesús
authors: J
authors: García-López
authors: Department of Bioinformatics Service, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain.
authors: Lola
authors: L
authors: Alonso
authors: Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain.
authors: David B
authors: DB
authors: Cárdenas
authors: Department of Bioinformatics Service, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain.
authors: Haydeé
authors: H
authors: Artaza-Alvarez
authors: Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain.
authors: Juan de Dios
authors: Jde D
authors: Hourcade
authors: Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain.
authors: Sergio
authors: S
authors: Martínez
authors: Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain.
authors: Miguel A
authors: MA
authors: Brieño-Enríquez
authors: Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), 28040 Madrid, Spain.
authors: Jesús
authors: J
authors: Del Mazo
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D005260:Female; D005306:Fertilization / Q000235:genetics*; D014644:Genetic Variation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D046228:Microarray Analysis; D058727:RNA, Small Untranslated / Q000235:genetics*; D013091:Spermatogenesis / Q000235:genetics*; D013094:Spermatozoa / Q000502:physiology*
chemical_list: D058727:RNA, Small Untranslated
keywords: germ cell development; miRNAs; next-generation sequencing; piRNAs; sncRNAs; snoRNAs