Meeting Abstract

P1.88  Jan. 4  Roles of NCX and PMCA in basolateral calcium export associated with mineralization cycles and low temperature acclimation in crayfish WHEATLY, MG*; GAO, Y; GILLEN, CM; STINER, LM; WHALEN, DR; NADE, M; VIGO, F; GOLSHANI, AE; Wright State University, Dayton; Wright State University, Dayton; Kenyon College, Gambier; Wright State University, Dayton; Wright State University, Dayton; Wright State University, Dayton; Wright State University, Dayton; Wright State University, Dayton michele.wheatly@wright.edu

Basolateral NCX and PMCA are the primary transmembrane proteins that export Ca from cells. In our lab we utilize a non-mammalian animal model, the freshwater crayfish, to study cellular Ca regulation. Two experimental conditions are employed to effect Ca dyshomeostasis: (1) in the postmolt stage of the crustacean molting cycle increased unidirectional Ca influx associated with cuticular mineralization is accompanied by elevated basolateral Ca export (compared with intermolt Ca balance) and (2) exposure of the poikilothermic crayfish to cold acclimation (4�C) causes influx of Ca into cells that is compensated by increased basolateral Ca export (compared with exposure to 23�C). This study compares expression of both NCX and PMCA mRNA (real-time PCR and in situ hybridization) and protein (Western) during elevated basolateral Ca export under both conditions. In postmolt we observed increases in NCX and PMCA expression (mRNA and protein) that were quantitatively higher in epithelial (kidney) versus non-epithelial tissues (axial muscle). In cold acclimation we also observed comparable increases in NCX and PMCA expression. The increased expression was localized in the nephridial canal in antennal gland and in the extensor muscles of the tail under both experimental treatments. (Funded by US NSF grant 0445202)