Terns R M, Kroll-Conner P, Zhu J, Chung S, Rothman J H
Department of Biochemistry, University of Wisconsin, Madison 53706, USA.
Genetics. 1997 May;146(1):185-206. doi: 10.1093/genetics/146.1.185.
To identify genomic regions required for establishment and patterning of the epidermis, we screened 58 deficiencies that collectively delete at least approximately 67% of the Caenorhabditis elegans genome. The epidermal pattern of deficiency homozygous embryos was analyzed by examining expression of a marker specific for one of the three major epidermal cell types, the seam cells. The organization of the epidermis and internal organs was also analyzed using a monoclonal antibody specific for epithelial adherens junctions. While seven deficiencies had no apparent effect on seam cell production, 21 were found to result in subnormal, and five in excess numbers of these cells. An additional 23 deficiencies blocked expression of the seam cell marker, in some cases without preventing cell proliferation. Two deficiencies result in multinucleate seam cells. Deficiencies were also identified that result in subnormal numbers of epidermal cells, hyperfusion of epidermal cells into a large syncytium, or aberrant epidermal differentiation. Finally, analysis of internal epithelia revealed deficiencies that cause defects in formation of internal organs, including circularization of the intestine and bifurcation of the pharynx lumen. This study reveals that many regions of the C. elegans genome are required zygotically for patterning of the epidermis and other epithelia.
为了确定表皮建立和模式形成所需的基因组区域，我们筛选了58个缺失突变体，这些突变体共同缺失了秀丽隐杆线虫基因组中至少约67%的区域。通过检测一种针对三种主要表皮细胞类型之一——边缘细胞的标记物的表达，来分析缺失纯合胚胎的表皮模式。还使用一种针对上皮黏着连接的单克隆抗体分析了表皮和内部器官的组织结构。虽然有7个缺失突变体对边缘细胞的产生没有明显影响，但发现有21个导致边缘细胞数量低于正常水平，5个导致边缘细胞数量过多。另外23个缺失突变体阻断了边缘细胞标记物的表达，在某些情况下并不妨碍细胞增殖。有两个缺失突变体导致多核边缘细胞。还鉴定出了一些缺失突变体，它们导致表皮细胞数量低于正常水平、表皮细胞过度融合形成一个大的合胞体或表皮分化异常。最后，对内部上皮组织的分析揭示了一些缺失突变体，它们导致内部器官形成缺陷，包括肠道环化和咽腔分叉。这项研究表明，秀丽隐杆线虫基因组的许多区域在合子阶段对于表皮和其他上皮组织的模式形成是必需的。
