Global characterization and target identification of piRNAs and endo-siRNAs in mouse gametes and zygotes.
A set of small RNAs known as rasRNAs (repeat-associated small RNAs) have been related to the down-regulation of Transposable Elements (TEs) to safeguard genome integrity. Two key members of the rasRNAs group are piRNAs and endo-siRNAs. We have performed a comparative analysis of piRNAs and endo-siRNAs present in mouse oocytes, spermatozoa and zygotes, identified by deep sequencing and bioinformatic analysis. The detection of piRNAs and endo-siRNAs in the spermatozoa and revealed also in zygotes, hints to their potential delivery to oocytes during fertilization. However, a comparative assessment of the three cell types indicates that both piRNAs and endo-siRNAs are mainly maternally inherited. Finally, we have assessed the role of the different rasRNA molecules in connection with amplification processes by way of the "ping-pong cycle". Our results suggest that the ping-pong cycle can act on other rasRNAs, such as tRNA- and rRNA-derived fragments, thus not only being restricted to TEs during gametogenesis.
Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain.
Jesús
J
García-López
Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain.
Juan de Dios
Jde D
Hourcade
Bioinformatics Service, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain.
Lola
L
Alonso
Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain.
David B
DB
Cárdenas
Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain. Electronic address: jdelmazo@cib.csic.es.
Jesús
J
del Mazo
D000818:Animals; D004251:DNA Transposable Elements / Q000235:genetics*; D005260:Female; D005718:Gametogenesis / Q000502:physiology*; D005854:Germ Cells / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism; D015053:Zygote / Q000378:metabolism*
D004251:DNA Transposable Elements; D034741:RNA, Small Interfering; D012343:RNA, Transfer
Deep sequencing; Endo-siRNA; Germ cell; Transposable element; Zygote; piRNAs