Differential activity of Ras1 during patterning of the Drosophila dorsoventral axis.
Differential activity of Ras1 during patterning of the Drosophila dorsoventral axis.
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作者：
Jon D. Schnorr;C. Berg
在果蝇中，Ras1 基因是受体酪氨酸激酶下游所必需的，以实现正确的眼睛发育、胚胎模式、翼静脉形成和边界细胞迁移。在这里，我们描述了 Ras1 的 P 元素等位基因 Ras1(5703)，它影响活力、眼睛形态发生以及卵子发生的早期和晚期阶段。 Ras1(5703) 和现有 EMS 诱导的 Ras1 等位基因的跨杂合果蝇是可行的，并表现出一系列眼睛和蛋壳缺陷。不同组织中这些表型的严重程度存在差异，表明 Ras1 在发育过程中存在等位基因特异性效应。对救援构建体的分析表明，这些差异表型是由于 Ras1 单独的功能丧失所致，而不是由于对邻近基因的影响所致。 Ras1 基因座突变的雌性产下的蛋背侧蛋壳结构减少或缺失。我们观察到 Ras1 突变体和其他背腹通路突变体（包括 Egfr（上）和 gurken）之间的显着相互作用。 Ras1 也对 K10 具有上位性。然而，与 Egfr（上）和 gurken 突变体不同，Ras1 雌性具有中等生育能力，产下的卵具有腹侧蛋壳，可以孵化正常幼虫。这些结果表明，在卵子发生过程中，Ras1 对蛋壳轴模式的要求可能与对胚胎轴模式的要求不同。
In Drosophila, the Ras1 gene is required downstream of receptor tyrosine kinases for correct eye development, embryonic patterning, wing vein formation, and border cell migration. Here we characterize a P-element allele of Ras1, Ras1(5703), that affects viability, eye morphogenesis, and early and late stages of oogenesis. Flies transheterozgyous for Ras1(5703) and existing EMS-induced Ras1 alleles are viable and exhibit a range of eye and eggshell defects. Differences in the severity of these phenotypes in different tissues suggest that there are allele-specific effects of Ras1 in development. Analysis of rescue constructs demonstrates that these differential phenotypes are due to loss of function in Ras1 alone and not due to effects on neighboring genes. Females mutant at the Ras1 locus lay eggs with reduced or missing dorsal eggshell structures. We observe dominant interactions between Ras1 mutants and other dorsoventral pathway mutants, including Egfr(top) and gurken. Ras1 is also epistatic to K10. Unlike Egfr(top) and gurken mutants, however, Ras1 females are moderately fertile, laying eggs with ventralized eggshells that can hatch normal larvae. These results suggest that Ras1 may have a different requirement in the patterning of the eggshell axis than in the patterning of the embryonic axis during oogenesis.