Wdr5及Wdr37基因在小鼠着床前胚胎发育中的作用

Many studies determined that the treatment of histone deacetylase inhibitor trichostatin A (TSA) can greatly improve the efficiency of nuclear reprogramming in mouse cloning. The genes affected by TSA may not only affect the development of somatic cloned embryos but also play an important role during the normal embryonic development process. Based on our previous microarray data, the gene expression profiles of cloned mouse embryos with or without TSA treatment and the fertilized embryos at 2-cell stage were compared. Wdr5 and Wdr37 with increased expression in both TSA treated cloned 2-cell embryos and fertilized 2-cell embryos were selected for the further studies. To investigate the functions of both genes during mouse preimplantation embryonic development, siRNA or overexpression RNA was injected into normal mouse 1-cell embryos. The formation of blastocyst, expression of the pluripotency-related genes and the modification of histone were detected.

研究表明应用组蛋白去乙酰化酶抑制剂曲古霉素A（trichostatin A，TSA）处理小鼠体细胞克隆胚胎可以显著提高体细胞克隆的效率，受TSA影响的基因不仅有可能是影响体细胞克隆胚胎发育的重要基因也有可能在正常的胚胎发育过程中发挥着重要的作用。本研究建立在小鼠着床前胚胎基因芯片分析的基础上，通过分析比较小鼠经TSA处理的体细胞克隆胚胎、未经TSA处理的体细胞克隆胚胎以及正常受精胚胎的2-细胞期基因表达谱，我们发现Wdr5和Wdr37在经TSA处理的体细胞克隆胚胎和正常受精胚胎中均比在未经TSA处理的体细胞克隆胚胎中表达量高，通过将siRNA和过表达RNA分别注射到正常小鼠1-细胞期胚胎中，检测小鼠囊胚形成率、多能性基因的表达以及组蛋白修饰，来确定这两个基因在小鼠着床前胚胎发育中的作用。

早期胚胎的发育受到多个基因的调节。本研究通过将siRNA或者过表达mRNA注射到小鼠1-细胞期胚胎中，通过体外培养来观察Wdr5或Wdr37基因对早期胚胎发育的影响。结果显示注射siRNA 24小时后，Wdr5或者Wdr37基因的表达量明显减少，但是经过培养发现囊胚形成率及囊胚期胚胎细胞数与对照组相比无明显差异。将过表达mRNA注射到1-细胞期胚胎中，经过体外培养发现过表达Wdr5或者Wdr37基因对囊胚形成率及囊胚期胚胎细胞数均无影响，这说明Wdr5或者Wdr37基因在早期胚胎发育过程中不发挥重要作用。由于Wdr37基因在早期胚胎中的表达量很高，所以我们制作了Wdr37基因敲除小鼠。结果发现敲除Wdr37后，雄性小鼠是不育的。这说明Wdr37基因在雄性生殖力上有重要作用。