为研究Amh基因在TSD(Temperature-dependent sex determination,温度依赖型性别决定)中的功能,文章以红耳龟Trachemys scripta为TSD动物模型,分析了Amh在胚胎性腺中的精细表达特征和细胞定位;通过基因功能缺失和获得研究手段,验证了Amh...为研究Amh基因在TSD(Temperature-dependent sex determination,温度依赖型性别决定)中的功能,文章以红耳龟Trachemys scripta为TSD动物模型,分析了Amh在胚胎性腺中的精细表达特征和细胞定位;通过基因功能缺失和获得研究手段,验证了Amh在TSD中的具体功能。表达分析结果显示,Amh基因在性腺分化启动前的第15期便已呈现产雄温度(Male-producing temperature,MPT)性腺高表达;AMH蛋白主要定位在MPT性腺sertoli前体细胞上,而在各个发育时期的FPT(Female-producing temperature,产雌温度)性腺中仅检测到极其微弱的Amh mRNA和蛋白表达信号。RNA干扰实验显示,敲低Amh后的MPT性腺出现了雄性向雌性完全性逆转,雄性分化因子Sox9明显下调,雌性分化因子Foxl2和Cyp19a1显著上调;相反地,异位表达Amh后的FPT性腺则转向睾丸方向分化,Foxl2和Cyp19a1表达被抑制,Sox9表达上升。上述研究表明,Amh是启动红耳龟早期睾丸分化必需且充分的关键因子,处于TSD雄性分化分子通路上游。展开更多
In previous work it was shown that mutation of site 1 in the downstream enhancer sequence (DE) led to ablation of enhancement. Mutation of the Wilms tumour factor element (Wt), situated in the Amh promoter between the...In previous work it was shown that mutation of site 1 in the downstream enhancer sequence (DE) led to ablation of enhancement. Mutation of the Wilms tumour factor element (Wt), situated in the Amh promoter between the tata box and the start of translation (TSS), also led to ablation of enhancement. This suggested that these sites may be the anchor points for a specific duplex factor bridging remote DNA elements to the promoter. Mutation analysis of the DNA sequence between sections 1 and 2 of DE was carried out by site directed mutagenesis. It is reported here that site 4 lying between DE1 and DE2, plays a key role in controlling the level of enhancement.展开更多
文摘In previous work it was shown that mutation of site 1 in the downstream enhancer sequence (DE) led to ablation of enhancement. Mutation of the Wilms tumour factor element (Wt), situated in the Amh promoter between the tata box and the start of translation (TSS), also led to ablation of enhancement. This suggested that these sites may be the anchor points for a specific duplex factor bridging remote DNA elements to the promoter. Mutation analysis of the DNA sequence between sections 1 and 2 of DE was carried out by site directed mutagenesis. It is reported here that site 4 lying between DE1 and DE2, plays a key role in controlling the level of enhancement.
