Oct4和Cdx2对牛胚胎内细胞团和滋养外胚层分化的影响

Effects of Oct4 and Cdx2 on differentiation of bovine embryonic inner cell mass and trophectoderm

目的研究Oct4和Cdx2敲低对牛ICM和TE分化相关的基因表达的影响,解释Oct4和Cdx2在牛胚胎早期发育中的作用。方法RNA干扰敲低牛胚胎Oct4或Cdx2基因。实时荧光定量PCR及免疫荧光染色检测敲低Oct4或Cdx2基因对牛胚胎早期发育及相关基因表达的影响。结果针对Oct4或Cdx2基因的特异性siRNA能够抑制牛胚胎Oct4或Cdx2表达。Oct4敲低对胚胎卵裂率和8-细胞率无影响,但胚胎囊胚率显著降低,mRNA水平显著下降(P<0.05)。Cdx2敲低抑制Oct4 mRNA表达(P<0.05)。结论Oct4通过调节Cdx2、Sox2及Nanog的表达控制牛胚胎的分化。

Objective To investigate the effects of Oct4 and Cdx2 knockdown on the expression of genes involved in ICM(Inner Cell Mass)and TE(Trophoectoderm)differentiation in cattle,and to elucidate the roles of Oct4 and Cdx2 in the early development of bovine embryos.Methods Oct4 and Cdx2 genes were knocked down in bovine embryos by RNA interference.Real-time quantitative PCR and immunofluorescence staining were used to observe the effects of knockdown on early embryo development and gene expression.Results Specific siRNAs against Oct4 and Cdx2 inhibited Oct4 and Cdx2 expression,respectively,in bovine embryos.Oct4 knockdown had no effect on embryonic cleavage and eight-cell proportions,although the blastocyst proportion was significantly reduced;moreover,the mRNA levels of Cdx2,Sox2,and Nanog were significantly reduced(P<0.05).Cdx2 knockdown inhibited the expression of Oct4 mRNA(P<0.05).Conclusions Oct4 controls the differentiation of bovine embryos by regulating the mRNA expression levels of Cdx2,Sox2,and Nanog.