Cell-autonomous roles of the ecdysoneless gene in Drosophila development and oogenesis
Cell-autonomous roles of the ecdysoneless gene in Drosophila development and oogenesis
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DOI：
10.1242/dev.01143
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发表时间：
2004-06-01
期刊：
影响因子：
4.6
通讯作者：
Jindra, M
中科院分区：
文献类型：
--
作者：
Gaziova, I;Bonnette, PC;Jindra, M
类固醇信号是动物发育过程的基础。果蝇类固醇激素合成的突变损害提供了工具，解剖类固醇激素的作用遗传。广泛使用的温度敏感突变ecdysoneless（1）（ecd（1））会破坏类固醇激素蜕皮激素的产生，并导致发育和生殖缺陷。如果不对ecd基因进行分析，就不能令人满意地解释这些缺陷。在这里，我们发现ecd编码一种在真核生物中保守的功能未知的蛋白质。ecd（1）条件等位基因含有一个氨基酸取代，而三个非条件幼虫致死突变导致截短的Ecd蛋白。与其在类固醇合成中的作用一致，Ecd在产生蜕皮激素的幼虫环腺中表达。然而，ecd无效的早期幼虫致死突变体的发展不能通过靶向环腺的Ecd表达或通过激素喂养来推进。这些实验表明，ecd（-）克隆不能在发育中的胚盘中存活，这证明了ecd的功能是细胞自主的。Ecd也在卵巢中表达，并且是卵母细胞发育所需的滤泡细胞和种系细胞。这些由ecd缺失引起的缺陷为这种进化上保守的蛋白质的细胞自主功能提供了第一个直接证据。
Steroid signaling underlies developmental processes in animals. Mutations that impair steroidogenesis in the fruit fly Drosophila melanogaster provide tools to dissect steroid hormone action genetically. The widely used temperature-sensitive mutation ecdysoneless(1) (ecd(1)) disrupts production of the steroid hormone ecdysone, and causes developmental and reproductive defects. These defects cannot be satisfactorily interpreted without analysis of the ecd gene. Here, we show that ecd encodes an as yet functionally undescribed protein that is conserved throughout eukaryotes. The ecd(1) conditional allele contains an amino acid substitution, whereas three non-conditional larval lethal mutations result in truncated Ecd proteins. Consistent with its role in steroid synthesis, Ecd is expressed in the ecdysone-producing larval ring gland. However, development of ecd-null early larval lethal mutants cannot be advanced by Ecd expression targeted to the ring gland or by hormone feeding. Cell-autonomous ecd function, suggested by these experiments, is evidenced by the inability of ecd(-) clones to survive within developing imaginal discs. Ecd is also expressed in the ovary, and is required in both the follicle cells and the germline for oocyte development. These defects, induced by the loss of ecd, provide the first direct evidence for a cell-autonomous function of this evolutionarily conserved protein.