Meeting Abstract

45.2  Thursday, Jan. 5  The identification of Cq-MAG, a novel androgenic gland-specific gene encoding a putative crustacean membrane-anchored protein ROSEN, Ohad*; MANOR, Rivka; WEIL, Simy; AFLALO, Eliahu D.; ABDU, Uri; SAGI, Amir; Ben Gurion University of the Negev; Ben Gurion University of the Negev; Ben Gurion University of the Negev; Ben Gurion University of the Negev; Ben Gurion University of the Negev; Ben Gurion University of the Negev roseno@bgu.ac.il

In crustaceans, male sexual differentiation and manifestation of secondary masculine sex characteristics are attributed to a proteinaceous androgenic gland (AG)-specific insulin-like hormone. Previously in the Australian red claw crayfish Cherax quadricarinatus, the hormone’s encoding gene (designated Cq-IAG) was identified using an AG cDNA library and its functionality was determined. In the present study, an additional AG-specific novel gene, encoding a putative membrane-anchored protein (termed Cq-MAG), has been identified. This is the first non-insulin-like AG-specific gene to be found in crustaceans. At the genomic level, Cq-MAG was shown to comprise of two exons and a single intron, and using molecular biology tools (e.g., RT-PCR, northern blot and RNA in situ hybridization) have demonstrated its mRNA tissue specificity. Cq-MAG was fully sequenced, revealing a cDNA sequence of 920 nucleotides encoding a putative translation product of 189 amino acids with a 42 amino acid-long signal anchor at its N-terminus. The expression of full length, truncated and mutated Cq-MAG fused to green fluorescent protein (GFP) in Drosophila Schneider cells, led to the identification of the signal require for anchoring the protein into membranes. Combining Cq-MAG’s specific expression localization and its signal anchor, along with the AG’s insulin secretion background, requires further investigation of Cq-MAG as a component of the secretion machinery needed for the discharge of the insulin-like AG hormone in crustaceans.