A translation-independent role of oskar RNA in early Drosophila oogenesis
A translation-independent role of oskar RNA in early Drosophila oogenesis
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DOI：
10.1242/dev.02456
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发表时间：
2006-08-01
期刊：
影响因子：
4.6
通讯作者：
Ephrussi, Anne
中科院分区：
文献类型：
--
作者：
Jenny, Andreas;Hachet, Olivier;Ephrussi, Anne
果蝇的母源效应基因oskar编码一种后端决定子，该决定子负责在卵子中形成后端极质，进而决定未来果蝇的腹部和生殖系的形成。先前鉴定出的oskar突变体会产生既没有腹部体节也没有生殖系的后代，从而定义了“后端组表型”。这些经典的oskar等位基因的共同特点是它们都能产生大量的oskar mRNA。相比之下，两个新的oskar突变体，其oskar RNA水平大幅降低或无法检测到，由于卵子发生的早期停滞而不育。这种无卵表型可由oskar无义突变等位基因以及oskar转基因（其编码蛋白质的能力已被消除）所弥补。此外，我们表明oskar的3'非翻译区（3'UTR）的表达足以挽救RNA缺失突变体的无卵缺陷。因此，我们的分析揭示了oskar RNA在卵子发生早期具有一种意想不到的作用，且这种作用不依赖于Oskar蛋白。这些发现表明oskar RNA作为一种支架或调控RNA，对卵母细胞的发育至关重要。
The Drosophila maternal effect gene oskar encodes the posterior determinant responsible for the formation of the posterior pole plasm in the egg, and thus of the abdomen and germline of the future fly. Previously identified oskar mutants give rise to offspring that lack both abdominal segments and a germline, thus de. ning the 'posterior group phenotype'. Common to these classical oskar alleles is that they all produce significant amounts of oskar mRNA. By contrast, two new oskar mutants in which oskar RNA levels are strongly reduced or undetectable are sterile, because of an early arrest of oogenesis. This egg-less phenotype is complemented by oskar nonsense mutant alleles, as well as by oskar transgenes, the protein-coding capacities of which have been annulled. Moreover, we show that expression of the oskar 3' untranslated region (3'UTR) is sufficient to rescue the egg-less defect of the RNA null mutant. Our analysis thus reveals an unexpected role for oskar RNA during early oogenesis, independent of Oskar protein. These findings indicate that oskar RNA acts as a scaffold or regulatory RNA essential for development of the oocyte.