BMP4对小鼠毛囊数量的影响

利用PolⅡ型人角蛋白14基因的启动子K14驱动eGFP-shRNA整合转录本的表达方法,制备在皮肤组织中高效表达靶向BMP4基因的siRNA转基因小鼠模型。利用Northern杂交的方法验证siRNA在转基因小鼠皮肤中高表达,但未从mRNA水平分析BMP4基因的表达变化。以建立的转基因小鼠模型为基础,检测小鼠皮肤组织中BMP4基因的表达变化,并观察妊娠18.5d(E18.5)转基因胎鼠与同窝阴性胎鼠背部皮肤组织切片中毛囊数量的变化,选择5个不同的视野进行毛囊数量计数后统计分析。结果表明,转基因小鼠皮肤组织中BMP4基因的表达下调,同时毛囊数量显著增加。表明利用融合表达载体制备转基因小鼠实现目的基因RNAi的方法可以有效地抑制动物体内目的基因的表达,同时也从胎鼠毛囊数量分析统计的结果发现,该基因对小鼠毛囊的发生发育有一定的影响。

Influence of BMP4 on Hair Follicles Quantity of Mice

RNA polymerase Ⅱ(Pol Ⅱ) promoter K14 was used to drive the expression of an eGFP-shRNA fusion mRNA.Transgenic mice were obtained with strong expression of the siRNA,which specifically inhibited BMP4 expression in the skin.And the previous studies have shown that siRNA expression was high level,but the mRNA expression level of BMP4 was not tested in transgenic mice.Therefore,we sought to clarify whether BMP4 expression is down-regulated.RT-PCR showed that BMP4 mRNA expression was down-regulated in the skin but not in muscle of wild-type littermates.The E18.5 dorsal skin of fetal mouse was sliced and the numbers of hair follicles were counted in five different fields.The numbers of follicles had a significant increase in transgenic mouse dorsal skin than in wild-type mouse.The results showed that down-regulation of BMP4 expression in the skin were associated with a significant increase of number of hair follicles.The results demonstrated that specific gene expression can be effectively reduced in transgenic mice carrying an RNAi fusion expression vector,and that the BMP4 gene may regulate hair follicle development.