SYNTHESIS OF A NEW SUBSTRATE FOR DETECTION OF LACZ GENE-EXPRESSION INLIVE DROSOPHILA EMBRYOS

Escherichia coli lacZ, which encodes beta-galactosidase, has become a widely used reporter gene to study the developmental regulation of gen e expression in a variety of organisms. To detect the presence of the beta-galactosidase, the sample must be fixed and appropriately stained . This sort of analysis yields rather crude estimates of the spatial t emporal changes in gene expression patterns. In addition, one cannot r ecover interesting specimens for propagation. A novel fluorogenic beta -galactosidase substrate for use in live Drosophila melanogaster embry os has been designed and synthesized This compound provides a means to determine gene dosage in live embryos so that one cart unambiguously determine the genotype of a living embryo. This will be useful for det ailed analysis of cellular and morphogenetic behavior changes in live embryos that are homozygous for embryonic lethal mutations. in the cou rse of testing this compound, a new beta-galactoside hydrolytic activi ty, different from the previous ly identified beta-galactosidase, has been discovered to reside in macrophages and the intervitelline space.