Ding D, Parkhurst S M, Lipshitz H D
Division of Biology, California Institute of Technology, Pasadena 91125.
Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2512-6. doi: 10.1073/pnas.90.6.2512.
The proteins encoded by polar-localized mRNAs play an important role in cell fate specification along the anteroposterior axis of the Drosophila embryo. The only maternally synthesized mRNA known previously to be localized to the anterior cortex of both the oocyte and the early embryo is the bicoid mRNA whose localization is required to generate a homeodomain protein gradient that specifies position along the anteroposterior embryonic axis. We have identified and characterized a second mRNA that is localized to the anterior pole of the oocyte and early embryo. This mRNA encodes a Drosophila homolog of mammalian adducin, a membrane-cytoskeleton-associated protein that promotes the assembly of the spectrin-actin network. A comparison of the spatial distribution of bicoid and Adducin-like transcripts in the maternal-effect RNA-localization mutants exuperantia, swallow, and staufen indicates different genetic requirements for proper localization of these two mRNAs to the anterior pole of the oocyte and early embryo.
由极性定位的mRNA编码的蛋白质在果蝇胚胎前后轴的细胞命运决定中发挥重要作用。先前已知唯一一种由母体合成且定位于卵母细胞和早期胚胎前皮质的mRNA是双胸mRNA，其定位对于产生沿胚胎前后轴确定位置的同源结构域蛋白梯度是必需的。我们已经鉴定并表征了第二种定位于卵母细胞和早期胚胎前极的mRNA。这种mRNA编码哺乳动物内收蛋白的果蝇同源物，一种促进血影蛋白-肌动蛋白网络组装的膜-细胞骨架相关蛋白。对母体效应RNA定位突变体exuperantia、swallow和staufen中双胸和类内收蛋白转录本的空间分布比较表明，这两种mRNA正确定位于卵母细胞和早期胚胎前极需要不同的遗传条件。
