MANOR, R*; WEIL, S ; OREN, S; AFLALO, E.D; VENTURA, T; LAPIDOT, M; CHALIFA-CASPI, V; SAGI, A; Ben-Gurion University of the Negev, Israel; Ben-Gurion University of the Negev, Israel; Ben-Gurion University of the Negev, Israel; Ben-Gurion University of the Negev, Israel; Ben-Gurion University of the Negev, Israel; Ben-Gurion University of the Negev, Israel; Ben-Gurion University of the Negev, Israel; Ben-Gurion University of the Negev, Israel: Fishing out uniquely expressed genes of the androgenic gland in the Australian crayfish Cherax quadricarinatus

The Australian crayfish Cherax quadricarinatus is a gonochoristic decapod species in which the androgenic gland (AG), an organ unique to male crustaceans, regulates sex differentiation, sexual secondary characteristics, and behavior. It is thought that the AG exerts its effects through androgenic gland hormone(s), not yet identified in decapods, whose synthesis and secretion are mediated by AG uniquely expressed genes. In order to identify such genes, a subtractive cDNA library of C. quadricarinatus AGs was constructed using cDNA from AGs as the “tester” and cDNA from other peripheral glands as the subtractive reference. cDNA products of the subtractive library were cloned, sequenced and an automated BLAST-X search suggested similarity to other known proteins in different organisms. So far, 200 sequences were analyzed and assembled into 49 putative genes, part of them could be assigned to metabolic pathways and a few were putatively identified as structural proteins. The majority of the putative genes showed no significant similarity to any known proteins in the Swiss-Prot database. Twenty of the above transcripts were tested by RT-PCR and two confirmed to be uniquely expressed in the AG. Northern blot analysis of these two genes revealed transcripts of 1000 and 2000 bp. Seeking full sequence of these uniquely expressed genes will help in identification of their functions.