Deficiency screen based on the monoclonal antibody MH27 to identify genetic loci required for morphogenesis of the Caenorhabditis elegans embryo.

The monoclonal antibody MH27 recognizes an adherens junction protein present around hypodermal cells in the pharynx and the intestine. By using this antibody and an antiserum against the LIN-26 protein, which is present in hypodermal and glial-like cells, I have examined the morphogenesis of the embryo in embryos homozygous for 91 chromosomal deficiencies that cover approximately 74% of the Caenorhabditis elegans genome. Most deficiencies were found to affect both the morphogenesis of the embryo and the organogenesis of the pharynx. By contrast, the intestine was generally normal. I have classified deficiencies according to their hypodermal staining abnormalities. I identified a few deficiencies that appeared to affect more specifically anterior-directed migration of hypodermal cells or extension of the margins of ventral hypodermal cells, integrity of hypodermal membranes, elongation of the embryo, and hypodermal cell fusions. This work opens the way for a genetic analysis of morphogenesis in C. elegans.