Serano T L, Cohen R S
Department of Biochemistry, University of Kansas, Lawrence 66045, USA.
Development. 1995 Sep;121(9):3013-21. doi: 10.1242/dev.121.9.3013.
Many of the genes that control pattern formation in Drosophila encode mRNAs that are localized to discrete regions of the oocyte during oogenesis. While such localization is generally assumed to be important for the pattern-forming activities of these genes, this has been rigorously demonstrated in only a few cases. Here we address the role of mRNA localization for the dorsoventral patterning gene K10. K10 mRNA is localized to the oocyte's anterior cortex following its transport into the cell during early stages of oogenesis. We show that mutations in cappuccino and spire, which permit K10 mRNA transport, but prevent subsequent anterior localization, do not disrupt the synthesis or localization of K10 protein. We also show that modified K10 transgenes that produce transcripts which are uniformly distributed throughout the oocyte, or which are mislocalized to the oocyte's posterior pole, produce localized and functional K10 protein. We conclude that the anterior localization of K10 mRNA is not important for K10 protein targeting or gene function. We propose that the anterior localization of K10, and probably other mRNAs, is a by-product of mRNA transport and does not necessarily reflect a requirement for localization per se.
许多控制果蝇模式形成的基因编码的mRNA在卵子发生过程中定位于卵母细胞的离散区域。虽然一般认为这种定位对于这些基因的模式形成活动很重要，但仅在少数情况下得到了严格证明。在这里，我们探讨mRNA定位对背腹模式形成基因K10的作用。K10 mRNA在卵子发生早期被转运到细胞中后定位于卵母细胞的前皮质。我们表明，卡布奇诺和螺旋蛋白中的突变允许K10 mRNA转运，但阻止随后的前侧定位，不会破坏K10蛋白的合成或定位。我们还表明，产生的转录本在整个卵母细胞中均匀分布或错误定位于卵母细胞后极的修饰K10转基因产生定位且有功能的K10蛋白。我们得出结论，K10 mRNA的前侧定位对于K10蛋白靶向或基因功能并不重要。我们提出，K10以及可能其他mRNA的前侧定位是mRNA转运的副产物，不一定反映对定位本身的需求。
