A NUCLEAR GFP BETA-GALACTOSIDASE FUSION PROTEIN AS A MARKER FOR MORPHOGENESIS IN LIVING DROSOPHILA

A general, non-invasive method to trace morphogenesis in living Drosop hila was developed. To label specific cells, green fluorescence protei n (GFP) of jellyfish Aequorea victoria was expressed by the Gal4-UAS s ystem. Green fluorescence from GFP fused to the nuclear localization s ignal was detectable in polytene larval tissue, but not in diploid tis sue. Further fusion to bacterial beta-galactosidase produced GFPN-lacZ , which fluoresced brightly in several diploid larval and embryonic ti ssues. GFPN-lacZ was used to trace dynamic cell movement during the fo rmation of the embryonic tracheal system. These results indicate that GFPN-lacZ can be used to mark specific cells to study cell movement an d gene expression in living animals.