Expression Of Mirnas In Mouse Preimplantation Embryos

MicroRNAs(miRNAs) are a 20-25nt single standed noncoding RNAs , and were distributed widely in Eukaryotes from C. elegans to human beings. MiRNAs have a characteristic of highly evolutionarily conservation and exihibit tissue-specific or developmental-stage-specific expression . their genes are not randomly distributed but often closely clustered on the genome . MiRNAs act as a gene regulation molecular and function through the regulation of their target genes by imperfect or perfect base-pairing with their target mRNAs, then either lead to the degradation of the target transcript or the inhibition of the protein translation .Through above mechnisim miRNAs play a important role in gene regulation network and play critical roles in many biological processes including the regulation of development, cell proliferation or differentiation, apoptosis and cancer formation .In this study , we intended to investigate the expression of miRNA-125a,miRNA-295,miRNA-181b in mouse preimplantation embryos and to analyze the function of miRNA acting on development and differentiation of preimplantation embryos .AIM : To set up a system about murine superovulation and mating and to establish a platform of embryo recovery to investigate the expression of miRNA-125a,miRNA-295,miRNA-181b in mouse preimplantation embryos and to futher illustrate the possible role and significance of miRNA in the preimplantational embryonic development .METHODS :miRNA specific RT primers were used to reversely transcribe the miRNAs including miR-125a,miR-295 and miR-181b, then miRNAs were amplified by SYBR Green real-time PCR using miRNA specific PCR primers. miR-125a,miR-295 and miR-181b were all expressed in mouse preimplantation embryos.RESULTS :With the embryo development, the expression of miR-295 is increased sharply and the expression of miR-125a was waved in differential stage of embryo development.CONCLUSION : The present study suggests that mouse preimplantation embryos express miRNAs.the development and cell differentiation of mouse preimplantation embryos are possiblely regulated by these miRNAs.