Dubowy J, Macdonald P M
Department of Biological Sciences, Stanford University, CA 94305, USA.
Mech Dev. 1998 Jan;70(1-2):193-5. doi: 10.1016/s0925-4773(97)00185-8.
Patterns of mRNA accumulation are sometimes dictated post-transcriptionally. Striking examples of mRNA localized to subcellular sites within cells have been described in animal oocytes, a variety of somatic cells in both animals and plants, and most recently in yeast (St Johnston, 1995; Bouget et al., 1996; Long et al., 1997; Takizawa et al., 1997). Some of the best characterized of the localized mRNAs come from the Drosophila ovary, where localization of three mRNAs--bicoid, oskar and gurken--within the oocyte defines the anteroposterior and dorsoventral body axes (reviewed in St Johnston, 1995). About 20 other mRNAs display a related pattern of localization, in which they become concentrated in the oocyte after transcription in the adjacent and interconnected nurse cells. Despite considerable work on the roles and mechanisms of mRNA localization, there have been no clear indications of the prevalence of this phenomenon, even in the much studied Drosophila system. Here we address this issue. We have examined the distributions of a random collection of individual Drosophila ovarian mRNAs, and find that a significant fraction, almost a tenth, are localized to the oocyte.
mRNA积累模式有时是在转录后决定的。在动物卵母细胞、动植物的多种体细胞以及最近在酵母中，都描述了mRNA定位于细胞内亚细胞位点的显著例子（St Johnston，1995；Bouget等人，1996；Long等人，1997；Takizawa等人，1997）。一些特征最明确的定位mRNA来自果蝇卵巢，其中三种mRNA——bicoid、oskar和gurken——在卵母细胞内的定位确定了前后和背腹体轴（见St Johnston的综述，1995）。另外约20种mRNA显示出相关的定位模式，它们在相邻且相互连接的滋养细胞中转录后在卵母细胞中浓缩。尽管对mRNA定位的作用和机制进行了大量研究，但即使在研究充分的果蝇系统中，也没有明确迹象表明这种现象的普遍性。在这里我们解决这个问题。我们检查了果蝇卵巢中单个mRNA的随机集合的分布，发现很大一部分，几乎十分之一，定位于卵母细胞。
