Meeting Abstract

P3-164  Wednesday, Jan. 6 15:30  Cloning of a cDNA encoding a sarco/endoplasmic reticulum Ca²⁺ ATPase from Y-organs of the blue crab (Callinectes sapidus) ROEGNER, ME*; CHEN, HY; WATSON, RD; University of Alabama at Birmingham; University of North Carolina Wilmington; University of Alabama at Birmingham mzappe@uab.edu

Stage-specific increases in intracellular free Ca²⁺ have been shown to stimulate ecdysteroid production in the molting glands (Y-organs) of crustaceans. Intracellular Ca²⁺ levels are regulated by proteins intrinsic to the plasma membrane and membranes of organelles. These include Ca²⁺ pumps, e.g., plasma membrane calcium ATPases (PMCAs) and sarco/endoplasmic reticulum calcium ATPases (SERCAs). In order to better understand the role of intracellular calcium signaling in the regulation of ecdysteroidogenesis, we used a PCR based cloning strategy (RT-PCR followed by 3’- and 5’-RACE) to clone a partial cDNA encoding a portion of a putative SERCA protein from the Y-organs of the blue crab (Callinectes sapidus). The cDNA includes an optimal translational initiation sequence, a start codon, and a 1749-bp open reading frame that encodes a 583 amino acid portion of a SERCA protein with 80% identity to comparable crustacean SERCA sequences. Experiments in progress are designed to clone the remainder of the SERCA cDNA and to assess SERCA transcript levels in the Y-organs and control tissues throughout the molting cycle using quantitative real-time PCR. We anticipate that the results will provide insight into the role of Ca²⁺ signaling and intracellular Ca²⁺ regulatory proteins in endocrine regulation of crustacean molting. (First and second authors contributed equally to this work).