Jankovics Ferenc, Sinka Rita, Lukácsovich Tamás, Erdélyi Miklós
Institute of Genetics, Biological Research Centre of the Hungarian Academy of Sciences, PO Box 521, H-6726 Szeged, Hungary.
Curr Biol. 2002 Dec 10;12(23):2060-5. doi: 10.1016/s0960-9822(02)01256-3.
In Drosophila, development of the embryonic germ cells depends on posterior transport and site-specific translation of oskar (osk) mRNA and on interdependent anchoring of the osk mRNA and protein within the posterior subcortical region of the oocyte. Transport of the osk mRNA is mediated by microtubules, while anchoring of the osk gene products at the posterior pole of the oocyte is suggested to be microfilament dependent. To date, only a single actin binding protein (TropomyosinII) has been identified with a putative role in osk mRNA and protein anchoring. This communication demonstrates that mutations in the Drosophila moesin (Dmoe) gene that encodes another actin binding protein result in delocalization of osk mRNA and protein from the posterior subcortical region and, as a consequence, in failure of embryonic germ cell development. In Dmoe mutant oocytes, the subcortical actin network is detached from the cell membrane, while the polarized microtubule cytoskeleton is unaffected. In line with the earlier observations, colocalization of ectopic actin and OSK protein in Dmoe mutants suggests that the actin cytoskeleton anchors OSK protein to the subcortical cytoplasmic area of the Drosophila oocyte.
在果蝇中，胚胎生殖细胞的发育依赖于osk（oskar）mRNA的后向运输和位点特异性翻译，以及osk mRNA和蛋白质在卵母细胞后皮质区域内的相互依赖锚定。osk mRNA的运输由微管介导，而osk基因产物在卵母细胞后极的锚定则被认为依赖于微丝。迄今为止，仅鉴定出一种肌动蛋白结合蛋白（原肌球蛋白II）在osk mRNA和蛋白质锚定中具有假定作用。本通讯表明，编码另一种肌动蛋白结合蛋白的果蝇埃兹蛋白（Dmoe）基因突变导致osk mRNA和蛋白质从后皮质区域发生异位，结果胚胎生殖细胞发育失败。在Dmoe突变体卵母细胞中，皮质下肌动蛋白网络与细胞膜分离，而极化的微管细胞骨架未受影响。与早期观察结果一致，Dmoe突变体中异位肌动蛋白和OSK蛋白的共定位表明，肌动蛋白细胞骨架将OSK蛋白锚定在果蝇卵母细胞的皮质下细胞质区域。
