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Small RNA class transition from siRNA/piRNA to miRNA during pre-implantation mouse development.

Ohnishi Y, Totoki Y, Toyoda A, Watanabe T, Yamamoto Y, Tokunaga K, Sakaki Y, Sasaki H, Hohjoh H - Nucleic Acids Res. (2010)

Bottom Line: Here, we show that during pre-implantation development a major small RNA class changes from retrotransposon-derived small RNAs containing siRNAs and piRNAs to zygotically synthesized microRNAs (miRNAs).Some siRNAs and piRNAs are transiently upregulated and directed against specific retrotransposon classes.Taken together, our current study reveals a major reprogramming of functional small RNAs during early mouse development from oocyte to blastocyst.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics, National Institute of Neuroscience, NCNP, Tokyo, Japan.

ABSTRACT
Recent studies showed that small interfering RNAs (siRNAs) and Piwi-interacting RNA (piRNA) in mammalian germ cells play important roles in retrotransposon silencing and gametogenesis. However, subsequent contribution of those small RNAs to early mammalian development remains poorly understood. We investigated the expression profiles of small RNAs in mouse metaphase II oocytes, 8-16-cell stage embryos, blastocysts and the pluripotent inner cell mass (ICM) using high-throughput pyrosequencing. Here, we show that during pre-implantation development a major small RNA class changes from retrotransposon-derived small RNAs containing siRNAs and piRNAs to zygotically synthesized microRNAs (miRNAs). Some siRNAs and piRNAs are transiently upregulated and directed against specific retrotransposon classes. We also identified miRNAs expression profiles characteristic of the ICM and trophectoderm (TE) cells. Taken together, our current study reveals a major reprogramming of functional small RNAs during early mouse development from oocyte to blastocyst.

Show MeSH
Proposed transition of functional small RNAs during mammalian oogenesis and early embryogenesis. Based on the present and previous study (13), possible changes in the levels of functional small RNAs from growing oocytes to pre-implantation embryos are represented schematically. Putative expression levels of zygotic siRNAs and piRNAs are represented by dotted lines and are not drawn in scale.
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Figure 5: Proposed transition of functional small RNAs during mammalian oogenesis and early embryogenesis. Based on the present and previous study (13), possible changes in the levels of functional small RNAs from growing oocytes to pre-implantation embryos are represented schematically. Putative expression levels of zygotic siRNAs and piRNAs are represented by dotted lines and are not drawn in scale.

Mentions: Together with the findings of recent studies (3,5,6,12–14), our current study has revealed that the transition of a major small RNA class from siRNA/piRNA to miRNA takes place during pre-implantation development (Figure 5). The data further suggest that the zygotic expression of miRNAs as the beginning of the transition presumably starts as early as the two-cell stage. Given that miRNA is a major mediator of gene regulation, and predominantly present in mammalian somatic cells including pluripotent ES cells (40,48,49), it is conceivable that early mammalian embryos shape the somatic type small RNA modality and gene regulation involving miRNAs prior to their implantation.Figure 5.


Small RNA class transition from siRNA/piRNA to miRNA during pre-implantation mouse development.

Ohnishi Y, Totoki Y, Toyoda A, Watanabe T, Yamamoto Y, Tokunaga K, Sakaki Y, Sasaki H, Hohjoh H - Nucleic Acids Res. (2010)

Proposed transition of functional small RNAs during mammalian oogenesis and early embryogenesis. Based on the present and previous study (13), possible changes in the levels of functional small RNAs from growing oocytes to pre-implantation embryos are represented schematically. Putative expression levels of zygotic siRNAs and piRNAs are represented by dotted lines and are not drawn in scale.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2926599&req=5

Figure 5: Proposed transition of functional small RNAs during mammalian oogenesis and early embryogenesis. Based on the present and previous study (13), possible changes in the levels of functional small RNAs from growing oocytes to pre-implantation embryos are represented schematically. Putative expression levels of zygotic siRNAs and piRNAs are represented by dotted lines and are not drawn in scale.
Mentions: Together with the findings of recent studies (3,5,6,12–14), our current study has revealed that the transition of a major small RNA class from siRNA/piRNA to miRNA takes place during pre-implantation development (Figure 5). The data further suggest that the zygotic expression of miRNAs as the beginning of the transition presumably starts as early as the two-cell stage. Given that miRNA is a major mediator of gene regulation, and predominantly present in mammalian somatic cells including pluripotent ES cells (40,48,49), it is conceivable that early mammalian embryos shape the somatic type small RNA modality and gene regulation involving miRNAs prior to their implantation.Figure 5.

Bottom Line: Here, we show that during pre-implantation development a major small RNA class changes from retrotransposon-derived small RNAs containing siRNAs and piRNAs to zygotically synthesized microRNAs (miRNAs).Some siRNAs and piRNAs are transiently upregulated and directed against specific retrotransposon classes.Taken together, our current study reveals a major reprogramming of functional small RNAs during early mouse development from oocyte to blastocyst.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics, National Institute of Neuroscience, NCNP, Tokyo, Japan.

ABSTRACT
Recent studies showed that small interfering RNAs (siRNAs) and Piwi-interacting RNA (piRNA) in mammalian germ cells play important roles in retrotransposon silencing and gametogenesis. However, subsequent contribution of those small RNAs to early mammalian development remains poorly understood. We investigated the expression profiles of small RNAs in mouse metaphase II oocytes, 8-16-cell stage embryos, blastocysts and the pluripotent inner cell mass (ICM) using high-throughput pyrosequencing. Here, we show that during pre-implantation development a major small RNA class changes from retrotransposon-derived small RNAs containing siRNAs and piRNAs to zygotically synthesized microRNAs (miRNAs). Some siRNAs and piRNAs are transiently upregulated and directed against specific retrotransposon classes. We also identified miRNAs expression profiles characteristic of the ICM and trophectoderm (TE) cells. Taken together, our current study reveals a major reprogramming of functional small RNAs during early mouse development from oocyte to blastocyst.

Show MeSH