Fertilization and Establishment of Polarity in the Embryo
Fertilization and Establishment of Polarity in the Embryo
复制标题
受精和胚胎极性的建立
DOI：
--
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
S. Strome
中科院分区：
文献类型：
--
作者：
K. Kemphues;S. Strome
I.引言秀丽隐杆线虫胚胎的身体计划是在最初的几次卵裂过程中建立的。这些裂解的可重复方向加上细胞质成分的不对称定位启动了建立身体三个主轴的过程，并确定了六个创始人细胞的命运。在本章中，我们回顾了目前对早期卵裂控制机制的理解，并讨论了以下问题：（1）胚胎极性何时以及如何建立，（2）细胞质因子如何沿轴沿着差异分配，（3）纺锤体定位如何控制以产生正确大小、正确位置和正确内容的细胞。A.胚胎发生概述为了详细描述C. elegans胚胎发生，参见Sulston et al.（1983），描述了整个胚胎谱系，以及Wood（1988）和Strome（1989）。在20°C下，新受精的胚胎需要14小时才能完成胚胎发育，并从蛋壳孵化成幼虫。在最初的几个小时内，胚胎经历了一系列的四次不等分裂，产生了五个体细胞创始人细胞（AB，E，MS，C和D）和原始生殖细胞（P 4），到28细胞阶段（图1和2）。1和2a-i）。当E的两个子代移到胚胎内部时，28细胞期开始形成原肠胚，随后是P 4和MS、C、D和AB的一些子代。这些细胞运动，再加上持续的增殖，导致了一个普遍的...
I. INTRODUCTION The body plan of the Caenorhabditis elegans embryo is established during the first few cleavages. The reproducible orientations of these cleavages coupled with asymmetric localization of cytoplasmic components initiate processes that establish the three principal axes of the body and set the fates of the six founder cells. In this chapter, we review the current understanding of mechanisms controlling the early cleavages, and we address the following issues: (1) when and how embryonic polarity is established, (2) how cytoplasmic factors are differentially partitioned along an axis, and (3) how spindle positioning is controlled to generate cells of the correct sizes, in the correct positions, and with the correct contents. A. Overview of Embryogenesis For detailed descriptions of C. elegans embryogenesis, see Sulston et al. (1983), which describes the entire embryonic lineage, and Wood (1988) and Strome (1989). It takes 14 hours at 20°C for a newly fertilized embryo to complete embryogenesis and hatch from its eggshell into a juvenile worm. During the first few hours, the embryo undergoes a series of four unequal divisions, to produce five somatic founder cells (AB, E, MS, C, and D) and the primordial germ cell (P 4 ) by the 28-cell stage (Figs. 1 and 2a–i). Gastrulation begins at the 28-cell stage when the two daughters of E move to the interior of the embryo (Fig. 2i), followed later by P 4 and some of the descendants of MS, C, D, and AB. These cell movements, coupled with continued proliferation, result in a generally...