Influence on spatiotemporal patterns of a male-specific Sox9 activation by ectopic Sry expression during early phases of testis differentiation in mice
Influence on spatiotemporal patterns of a male-specific Sox9 activation by ectopic Sry expression during early phases of testis differentiation in mice
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DOI：
10.1016/j.ydbio.2004.11.006
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发表时间：
2005-02-15
影响因子：
2.7
通讯作者：
Yonekawa, H
中科院分区：
文献类型：
--
作者：
Kidokoro, T;Matoba, S;Yonekawa, H
哺乳动物睾丸的诱导与性腺Sry和Sox9的表达有关。本研究探讨了在睾丸分化的早期阶段，Sty的表达是否直接诱导了雄性特异性Sox9的激活。我们已经建立了一个携带Sry转基因的XX性逆转小鼠系，该转基因由Hsp70.3基因的弱碱基启动子驱动(HSP-Sry)，由此转基因从早期就沿着整个前后轴在性腺中被激活。以转HSP-Sry基因胚胎的XX和XY性腺为材料，研究了Siy基因的错误表达和过表达对Sox9基因表达的时空格局的影响。结果表明，早期阶段SRI1在整个性腺区的异位表达既没有促进时间的提前，也没有促进内源性Sox9表达的任何明显的异位激活。但在Sox9激活后即刻，HSP-Sry/XY性腺的Sox9表达水平和SOX9阳性细胞数显著高于野生型/XY和HSP-Sry/XX性腺。这些发现表明，尽管Siy能够剂量依赖地上调Sox9的表达，但Sly mRNA的单独表达不太可能提供雄性特异性Sox9在发育XY性腺中激活所需的位置或时间信息。(C)2004 Elsevier Inc.保留所有权利。
Testis induction is associated with gonadal Sry and Sox9 expression in mammals. This study investigated whether Sty expression directly induces male-specific Sox9 activation during early phases of testis differentiation. We have established an XX sex-reversal mouse line carrying the Sry transgene driven by a weak basal promoter of the Hsp70.3 gene (Hsp-Sry), whereby the transgene was activated in the gonads along the entire anteroposterior axis from earlier stages. The effects of misexpression and overexpression of Siy on the spatiotemporal pattern of Sox9 expression were examined using both XX and XY gonads of Hsp-Sry transgenic embryos. It was shown that ectopic expression of Sri; transcripts in the entire gonadal area from earlier stages promotes neither any advance in the timing nor any appreciable ectopic activation of endogenous Sox9 expression. Immediately after the onset of Sox9 activation, however, both the level of Sox9 expression and the number of SOX9-positive cells were significantly enhanced in Hsp-Sry/XY gonads, as compared with those in wild-type/XY and Hsp-Sry/XX gonads. These findings suggest that, although Siy is capable of up-regulating Sox9 expression dose-dependently, Sly mRNA expression alone is not likely to provide positional or timing information needed for male-specific Sox9 activation in developing XY gonads. (C) 2004 Elsevier Inc. All rights reserved.