Expression of P-glycoprotein in southeastern oysters, Crassostrea virginica

These studies provide important fundamental information regarding the expre ssion of P-glycoprotein (p-gp) in southeastern oysters (Crassostrea virgini ca). Using rhodamine transport studies, p-gp activity was detected in newly fertilized embryos. A monoclonal antibody (C219) was used to evaluate P-gp expression in oyster tissues. On the basis of laboratory studies, p-gp exp ression tended to be higher in gill tissues than mantle tissues, and was ge nerally not related to salinity differences. Seasonal studies were conducte d with oysters collected monthly for 1 year from Lighthouse Creek, an unpol luted site. There was a general pattern of higher p-gp expression in the wa rmer months and lower expression in the colder months. In contrast, total g ill protein concentrations decreased during the warmer months and increased during the colder months. These studies indicate that there are seasonal p atterns in p-gp expression which may represent an adaptive response to natu ral stressors associated with summer conditions. (C) 2001 Elsevier Science Ltd. All rights reserved.