Meeting Abstract
92.4 Wednesday, Jan. 7 A Novel Molt-related Protein with a Possible Role in the Formation of Crayfish Calcium Storage Deposits GLAZER, L.*; SHECHTER, A.; BERMAN, A.; WEIL, S.; AFLALO, E.D.; YUDKOVSKI, Y.; TOM, M.; SAGI, A.; 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; 4Israel Oceanographic and Limnological Research; 4Israel Oceanographic and Limnological Research; Ben-Gurion University of the Negev sagia@bgu.ac.il
During premolt, the crayfish Cherax quadricarinatus transports and stores calcium in a pair of transient deposits termed gastroliths. Gastroliths, formed in a cavity between the cardiac stomach wall and the columnar gastrolith epithelial tissue, are composed of chitinous organic matrix with associated proteins, and of amorphous calcium carbonate. Initiation of premolt and gastrolith formation is achieved by administration of the molting hormone ecdysone. In search for molt-related proteins involved in gastrolith formation we have isolated several novel proteins, termed gastrolith proteins (GAP), from the extracellular matrix of the gastrolith, and fully sequenced their transcripts. The deduced protein of a gene called GAP 10 has a molecular weight of 10kDa, is glycine-rich and has an acidic pI. It contains two predicted features; signal sequence and phosphorylation sites. GAP 10, was found to be highly up-regulated during premolt vs. intermolt in a multigenic search for expression patterns of gastrolith forming tissue specifically expressed genes, conducted using a C.quadricarinatus cDNA microarray chip. The chip was assembled from a gastrolith forming tissue cDNA suppression-subtractive hybridization (SSH) library and three additional SSH libraries of other tissues, all from ecdysone-induced premolt individuals. Due to its prominent up-regulation, GAP 10 was chosen as a target for functional genomic investigation, for the elucidation of its role in gastrolith formation.
