Forristall C, Pondel M, Chen L, King M L
Department of Cell Biology and Anatomy (R-124), University of Miami School of Medicine, FL 33101.
Development. 1995 Jan;121(1):201-8. doi: 10.1242/dev.121.1.201.
In Xenopus, localization of a rare class of mRNAs during oogenesis is believed to initiate pattern formation in the early embryo. We have determined the pattern of RNA localization for one of these RNAs, Xcat-2, which encodes a putative RNA-binding protein related to Drosophila nanos (Mosquera, L., Forristall, C., Zhou, Y. and King, M. L. (1993) Development 117, 377-386). Xcat-2 is exclusively localized to the mitochondrial cloud in stage I oocytes, moves with this body into the vegetal cortex during stage II and, later, partitions into islands consistent with it being a component of the germ plasm. As previously shown, Vg1 is not localized to the vegetal cortex until stage IV and distributes to all vegetal blastomeres during development. We found a direct correlation between the localized condition of these RNAs and their recovery in a detergent-insoluble fraction. We present evidence suggesting that differential RNA binding to a cytoskeletal component(s) in the vegetal cortex determines the pattern of inheritance for that RNA in the embryo.
在非洲爪蟾中，一类罕见的mRNA在卵子发生过程中的定位被认为启动了早期胚胎的模式形成。我们已经确定了其中一种RNA，即Xcat-2的RNA定位模式，它编码一种与果蝇nanos相关的假定RNA结合蛋白（Mosquera, L., Forristall, C., Zhou, Y.和King, M. L. (1993) Development 117, 377 - 386）。Xcat-2仅定位于I期卵母细胞的线粒体云，在II期时随该结构移入植物皮质，随后，分隔成岛屿状，这与它作为生殖质的一个组成部分一致。如先前所示，Vg1直到IV期才定位于植物皮质，并在发育过程中分布到所有植物极卵裂球。我们发现这些RNA的定位状态与其在去污剂不溶性组分中的回收之间存在直接相关性。我们提供的证据表明，RNA与植物皮质中的细胞骨架成分的差异结合决定了该RNA在胚胎中的遗传模式。
