STILLMAN, J.S.; University of Hawaii, Manoa: Correlations between physiological and transcriptome responses to thermal acclimation in the porcelain crab Petrolisthes cinctipes

Porcelain crabs, genus Petrolisthes, are common inhabitants of the marine intertidal zone where they may experience rapid and large changes in habitat temperature during the low tide period. These crabs are known to have evolved upper thermal limits that are correlated with the maximal habitat temperatures that they experience, and, species from different thermal microhabitats are known to have different capacities for thermal acclimation of upper and lower thermal limits. Here, I present initial findings from a study of the correlation between the thermal limits of cardiac function and patterns of gene expression in species, P. cinctipes. To monitor patterns of gene expression, a 4992-spot cDNA microarray was generated from mRNA extracted from P. cinctipes tissues. Crabs were acclimated to either a cycling thermal regime where the water temperature increased from 8 to 26�C in a 6h period (simulating the thermal condition of a summertime low tide period) and then returned to 8�C for the remainder of the day, or to a constant thermal regime where crabs were held at either 8 or 18�C for 4 weeks and were then swapped to the alternate treatment and held for several days. The results of heart rate studies indicate that upper thermal limits of cardiac function acclimated more slowly than lower thermal limits in this species. Initial results for gene expression in three tissues (hepatopancreas, gill, and muscle) indicate that there are tissue-specific responses to the thermal acclimations. In hepatopancreas, one of the genes that responded strongly to the cycling thermal acclimation condition is in the hemocyanin family, and identification of additional genes with interesting patterns of expression is underway.