THE DROSOPHILA EBONY GENE IS CLOSELY-RELATED TO MICROBIAL PEPTIDE SYNTHETASES AND SHOWS SPECIFIC CUTICLE AND NERVOUS-SYSTEM EXPRESSION

The previously detected ebony (e) locus (Caizzi et al., 1987) consists of a complex gene structure that is divided into seven exons. An open reading frame encoding the putative Ebony protein of 98.5 kDa exhibit s homology to a family of peptide synthetases (Stachelhaus and Marahie l, 1995), in good correlation with the proposed function as P-alanyl-d opamine synthetase. Multiple ebony transcripts are detected throughout development. P-factor mediated transformation of genomic DNA rescues the cuticle, electrophysiological and behavioural phenotypes. Fusion o f the ebony reading frame with that of P-galactosidase of E. coli reve als expression in cuticle and nervous system. Strong staining in the f irst and, to a lesser extent, in the second optic neuropile may reflec t the pronounced visual defect observed in ebony mutants. In addition, weak central brain and thoracic ganglion expression is detected in fl ies. Conservation of a multidomain protein structure known from peptid e synthetases should have functional implications on the putative reac tion mechanism of peptide bond formation. (C) 1998 Elsevier Science B. V. All rights reserved.