Cytoplasmic flows localize injected oskar RNA in Drosophila oocytes
Cytoplasmic flows localize injected oskar RNA in Drosophila oocytes
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DOI：
10.1016/s0960-9822(06)00156-4
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发表时间：
1997-05-01
期刊：
影响因子：
9.2
通讯作者：
Ephrussi, A
中科院分区：
文献类型：
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作者：
Glotzer, JB;Saffrich, R;Ephrussi, A
工作背景：oskar（osk）基因编码果蝇后极身份的决定因子，osk RNA定位于卵母细胞后极的极浆中，对胚胎的发育至关重要。osk RNA定位的机制是unknow.Results：为了研究osk RNA定位的机制，我们在第9，10和11阶段将荧光标记的RNA注入卵母细胞。注射的osk RNA定位于极细胞质，再现内源RNA的定位。在第10和11阶段的卵母细胞中，注射的osk RNA的长距离运动由强有力的微管依赖性细胞质流或卵质流促进。用秋水仙碱（一种微管去稳定化药物）治疗，可抑制卵浆流动，并防止RNA从后极远端注射部位定位。然而，如果RNA被注射到靠近后极的地方，即使在秋水仙素存在的情况下，它也会定位。同样，在小的卵母细胞，如第9阶段卵母细胞，本地化的注射osk RNA是不敏感的秋水仙素。结论：这些结果表明，微管依赖的细胞质流可能有助于osk RNA的远程运输，而微管独立的过程可以介导短程运输。这些结果也突出了osk RNA锚在定位过程中的作用。
Background: The oskar (osk) gene encodes a determinant of posterior identity in Drosophila, and the localization of osk RNA to the pole plasm at the posterior pole of the oocyte is essential for development of the embryo. The mechanisms by which osk RNA is localized are unknown.Results: To study the mechanisms underlying localization of osk RNA, we have injected fluorescently labelled RNA into oocytes at stages 9, 10 and 11. Injected osk RNA localizes to the pole plasm, reproducing localization of the endogenous RNA. In oocytes at stages 10 and 11 the long-range movement of injected osk RNA is promoted by a vigorous, microtubule-dependent cytoplasmic flow, or ooplasmic streaming. Treatment with colchicine, a microtubule-destabilizing drug, inhibits ooplasmic streaming and prevents localization of the RNA from an injection site distal to the posterior pole. If the RNA is injected close to the posterior pole, however, it localizes even in the presence of colchicine. Similarly, in small oocytes, such as stage 9 oocytes, localization of injected osk RNA is insensitive to colchicine.Conclusions: These results reveal that microtubule-dependent cytoplasmic flows could contribute to the long-range transport of osk RNA, whereas microtubule-independent processes could mediate short-range transport. These results also highlight the role of the osk RNA anchor in the localization process.