C.elegans野生型和par突变体早期胚胎卵裂的观察

不对称分裂在动植物的发育中起到了非常重要的作用。Caenorhabditis elegans（C．elegans）胚胎最早的两次卵裂为研究控制不对称分裂的机制提供了很好的机会。用普通光学显微镜观察了野生型胚胎早期卵裂和par-1、par-2、par-3、par-4突变体胚胎的早期卵裂。野生型胚胎最早的分裂是不等的，产生了两个不同大小的子细胞。两个子细胞又以不同的方向进行第二次分裂。在C．elegans中任意一个par基因的缺失会使胚胎的第一次卵裂丧失不对称性。这会导致一些发育调控因子不能在特定的胚胎细胞中准确地定位，造成细胞分裂纺锤体方向的异常。par类基因参与不对称性的建立，这种不对称性决定了C．elegans身体的前后轴。

The Observation of the Early Embryo Development in Wild-type and par Mutant of C.elegans

Asymmetric divisions play important roles in the development of plants and animals. The first two embryonic cleavages of Caenorhabditis elegans (C. elegans) provide an opportunity to study the mechanisms controlling asymmetric divisions. In this article, early embryogenesis of wide type and par-1 through par-4 mutant are observed by microscope. The first cleavage of wild type embryo is unequal, producing daughters with different sizes. The daughter blastomeres divide with different orientations of spindles. Loss-of-function mutations in any par locus results in loss of anterior-posterior (AP) asymmetries during the first two embryonic cell divisions. This results in a failure to restrict developmental regulators to specific embryonic cells and mitotic spindle orientation defects. In sum, the par genes appear responsible for establishing asymmetries that define the AP body axis in C.elegans.