EXPRESSION OF THE WILMS-TUMOR GENE WT1 IN THE MURINE UROGENITAL SYSTEM
EXPRESSION OF THE WILMS-TUMOR GENE WT1 IN THE MURINE UROGENITAL SYSTEM
复制标题
DOI：
10.1101/gad.5.8.1345
复制
发表时间：
1991-08-01
影响因子：
10.5
通讯作者：
HOUSMAN, D
中科院分区：
文献类型：
--
作者：
PELLETIER, J;SCHALLING, M;HOUSMAN, D
Wilms肿瘤基因WT1是一种隐性癌基因，其编码一种被认为与肾脏发育过程中肾脏发生有关的转录因子。在本报告中，我们分析了WT1在小鼠泌尿生殖系统中的表达。WT1在年轻和成年小鼠的睾丸和卵巢的非生殖细胞成分中表达。原位mRNA杂交研究表明，WT1在卵巢颗粒和上皮细胞、睾丸支持细胞和子宫壁中表达。除了通过Northern blotting检测到来自肾脏、子宫和性腺的3.1 kb的WT1转录物外，在睾丸中还有大约2.5 kb的WT1相关mRNA物种。生殖腺中WT1 mRNA的水平是观察到的最高的，超过了胚胎肾脏中检测到的量。在发育过程中，这些水平受到不同的调节，取决于性腺的性别分化。产后4 ~ 40天，女性生殖系统中WT1 mRNA的表达无明显波动。相比之下，出生后睾丸中WT1 mRNA水平稳步上升，在产后第8天达到最高表达水平，随着动物的成熟略有下降。在性腺中，WT1的表达早在性交后12.5天就可以检测到（p.c）。作为探索WT1组织特异性表达的第一步，我们克隆并测序了WT1上游的DNA元件。三个假定的转录起始位点，用于睾丸，卵巢和子宫，绘制了S1核酸酶保护试验。这些位点周围的序列具有较高的G + C含量，不存在典型的上游CCAAT和TATAA盒。这些研究使我们能够确定WT1蛋白合成的翻译起始位点。我们还使用表位标记方案来证明WT1是一种核蛋白，与其作为转录因子的作用一致。我们的研究结果证实了生殖腺发育过程中WT1表达的调控，暗示WT1与泌尿生殖系统发育有关，并为理解Wilms肿瘤遗传病例中观察到的泌尿生殖系统缺陷提供了分子框架。
The Wilms' tumor gene WT1 is a recessive oncogene that encodes a putative transcription factor implicated in nephrogenesis during kidney development. In this report we analyze expression of WT1 in the murine urogenital system. WT1 is expressed in non-germ-cell components of the testis and ovaries in both young and adult mice. In situ mRNA hybridization studies demonstrate that WT1 is expressed in the granulosa and epithelial cells of ovaries, the Sertoli cells of the testis, and in the uterine wall. In addition to the 3.1-kb WT1 transcript detected by Northern blotting of RNA from kidney, uterus, and gonads, there is an approximately 2.5-kb WT1-related mRNA species in testis. The levels of WT1 mRNA in the gonads are among the highest observed, surpassing amounts detected in the embryonic kidney. During development, these levels are differentially regulated, depending on the sexual differentiation of the gonad. Expression of WT1 mRNA in the female reproductive system does not fluctuate significantly from days 4 to 40 postpartum. In contrast, WT1 mRNA levels in the testis increase steadily after birth, reaching their highest expression levels at day 8 postpartum and decreasing slightly as the animal matures. Expression of WT1 in the gonads is detectable as early as 12.5 days postcoitum (p.c.). As an initial step toward exploring the tissue-specific expression of WT1, DNA elements upstream of WT1 were cloned and sequenced. Three putative transcription initiation sites, utilized in testis, ovaries, and uterus, were mapped by S1 nuclease protection assays. The sequences surrounding these sites have a high G + C content, and typical upstream CCAAT and TATAA boxes are not present. These studies allowed us to identify the translation initiation site for WT1 protein synthesis. We have also used an epitope-tagging protocol to demonstrate that WT1 is a nuclear protein, consistent with its role as a transcription factor. Our results demonstrate regulation of WT1 expression during development of the gonads, implicate WT1 in genitourinary development, and provide a molecular framework toward understanding genitourinary defects observed among hereditary cases of Wilms' tumor.