Expression of both the 48.1C and 41.2C transgenes was consistently observed in embryos from gastrulation onward, in all larval stages and in adults. In postembryonic stages, both transgenes were expressed in most tissues. Although 41.2C is expressed in numerous tissues, especially the pharynx and gut, it is not expressed in the gonad. 41.8C express in a tissue general fashion and expression s in every cell type has been observed in strains carrying this transgene, including neurons, muscle, intestine, and hypodermis. Only the germ-line failed to express this fusion gene. Tissues expressing the hsp-16
::lacZ fusion in these strains include nerve ganglia in the head and ventral cord; hypodermal nuclei of the lateral hypodermis, vulva, head and tail, body wall and pharyngeal muscle, somatic gonad, mesodermal tissue such as coelomocytes, and muscles involved in defecation. On the other hand, subtle differences in the expression pattern of these two transgenes were identified. 41.2C stain most intensely throughout the pharynx whereas 48.1C demonstrated conspicuous expression in body wall muscle.