Identification and characterization of kraken, a gene encoding a putative hydrolytic enzyme in Drosophila melanogaster

Kraken, a novel Drosophila gene isolated from a 4-8-h-old Drosophila embryo cDNA library, shows homology to a family of serine hydrolases whose common feature is that they all catalyse breakage of substrates with a carbonyl-c ontaining group. It is a single-copy gene with at least two introns and map s to position 21D on polytene chromosomes. kraken is a member of a conserve d gene family. Messenger RNA of kraken is expressed ubiquitously in early e mbryogenesis. Later, it is concentrated in the foregut and the posterior mi dgut primordium. Towards the end of embryogenesis, expression of kraken is confined to the gastric caeca. During the third-instar larval stage, kraken is expressed at low levels in the gastric caeca and parts of the gut, and at higher levels in the fat body. We suggest a role for Kraken in detoxific ation and digestion during embryogenesis and larval development. (C) 1998 E lsevier Science B.V. All rights reserved.