Wallingford J B, Carroll T J, Vize P D
Department of Zoology, University of Texas, Austin, Texas, 78712, USA.
Dev Biol. 1998 Oct 1;202(1):103-12. doi: 10.1006/dbio.1998.8989.
The tumor suppressor WT1 has been demonstrated to have a wide variety of activities in vitro and is required for metanephric development in vivo. In the experiments presented here, the Xenopus pronephros was used as a simple model system to examine the activity of Xenopus WT1 (xWT1) during kidney development. xWT1 was ectopically expressed in Xenopus embryos by mRNA injection and found to inhibit pronephric tubule development. Confocal microscopy confirmed this observation and revealed that the inhibition was the result of a failure to form a pronephric anlage of appropriate size rather than a defect in epithelialization. Examination of Xlim-1 expression, an early molecular marker of pronephric specification, in tailbud embryos indicated that injected xWT1 mRNA inhibited pronephric specification prior to any overt sign of morphogenesis (Xenopus stage 21). These results suggest that xWT1 may act to repress tubule-specific gene expression in the portion of the pronephros fated to form its vascular structure, the glomus.
肿瘤抑制因子WT1已被证明在体外具有多种活性，并且在体内是后肾发育所必需的。在本文所述的实验中，非洲爪蟾前肾被用作一个简单的模型系统，以研究非洲爪蟾WT1（xWT1）在肾脏发育过程中的活性。通过mRNA注射将xWT1异位表达于非洲爪蟾胚胎中，发现其抑制前肾小管发育。共聚焦显微镜证实了这一观察结果，并揭示这种抑制是由于未能形成适当大小的前肾原基，而非上皮形成缺陷所致。对尾芽胚胎中前肾特化的早期分子标志物Xlim-1表达的检测表明，注射的xWT1 mRNA在形态发生的任何明显迹象（非洲爪蟾第21阶段）之前就抑制了前肾特化。这些结果表明，xWT1可能在注定形成其血管结构即肾小球的前肾部分中，发挥抑制肾小管特异性基因表达的作用。
