Byrne Michael J, Warner Carol M
Biology Department, Northeastern University, 134 Mugar Hall, 360 Huntington Avenue, Boston, MA, 02115, USA.
J Assist Reprod Genet. 2008 May;25(5):205-14. doi: 10.1007/s10815-008-9211-8. Epub 2008 Mar 18.
The mouse preimplantation embryo development (Ped) gene product, Qa-2, influences the rate of preimplantation embryonic development and overall reproductive success. Here we investigated the expression pattern of two microRNAs, miR-125a and miR-125b, known to be involved in development in lower organisms, in preimplantation embryos from the two-cell, four-cell, eight-cell, morula, and blastocyst stages of development from the congenic B6.K1 (Ped negative) and B6.K2 (Ped positive) strains of mice.
B6.K1 and B6.K2 congenic mice differ only in the absence (B6.K1) or presence (B6.K2) of the genes encoding Qa-2 protein. We analyzed the expression of miR-125a and miR-125b in B6.K1 and B6.K2 preimplantation embryos by using real-time PCR.
We found no variability in miR-125b expression at any developmental stage in both strains. However, miR-125a expression increased during development in both strains and was ten times higher in Ped negative (B6.K1) embryos than in Ped positive (B6.K2) embryos by the blastocyst stage of development.
Our results show that the absence of the Ped gene profoundly affects the level of a miRNA (miR-125a) known to regulate early development. The implication is that miR-125a is likely involved in the regulation of timing of early development in mice.
小鼠植入前胚胎发育（Ped）基因产物Qa - 2会影响植入前胚胎发育速率和整体繁殖成功率。在此，我们研究了已知参与低等生物发育的两种微小RNA（miR - 125a和miR - 125b）在同基因B6.K1（Ped阴性）和B6.K2（Ped阳性）品系小鼠从二细胞、四细胞、八细胞、桑葚胚和囊胚阶段的植入前胚胎中的表达模式。
B6.K1和B6.K2同基因小鼠仅在编码Qa - 2蛋白的基因缺失（B6.K1）或存在（B6.K2）方面存在差异。我们通过实时PCR分析了B6.K1和B6.K2植入前胚胎中miR - 125a和miR - 125b的表达。
我们发现两种品系在任何发育阶段miR - 125b的表达均无变化。然而，两种品系中miR - 125a的表达在发育过程中均增加，并且在发育至囊胚阶段时，Ped阴性（B6.K1）胚胎中的miR - 125a表达比Ped阳性（B6.K2）胚胎高十倍。
我们的结果表明，Ped基因的缺失深刻影响了已知调节早期发育的一种微小RNA（miR - 125a）的水平。这意味着miR - 125a可能参与小鼠早期发育时间的调节。
