MOLECULAR MARKERS OF DIFFERENTIATION IN CAENORHABDITIS-ELEGANS OBTAINED BY PROMOTER TRAPPING

Differentiation of specific cell types during animal development can b e detected by monitoring expression of appropriate genes. For this stu dy, six different beta-galactosidase expression patterns which can be used as differentiation markers in the nematode Caenorhabditis elegans are described. An earlier promoter trap screen identified pools of re combinant plasmids which gave patterns of beta-galactosidase expressio n when used to transform C. elegans. Each recombinant plasmid containe d a random fragment of C. elegans genomic DNA fused upstream of a prom oterless lacZ gene. Six of these pools were chosen, and individual pat tern-producing plasmids within these pools were identified. The expres sion patterns have been characterized more thoroughly than in the orig inal screen, thereby providing molecular markers for differentiation o f several cell types. Many of the expression patterns involve more tha n one cell type. The genomic origin of the inserts of active plasmids were determined through localization on the physical genome map. (C) 1 993 Wiley-Liss, Inc.