Meeting Abstract

1.2  Monday, Jan. 4  Comparative Proteomics: The Response of the Ascidian Congeners Ciona intestinalis and C. savignyi to Acute Temperature Stress SERAFINI, L.*; TOMANEK, L.; Cal Poly, SLO; Cal Poly, SLO lserafin@calpoly.edu

Ciona intestinalis and C. savignyi are congeneric tunicates that are commonly found along the Pacific coast of North America. In order to compare the thermal stress response between these two sister species, we studied global changes in protein expression in response to heat stress using proteomics. The ascidians’ phylogenetic position as urochordates, along with their sequenced genomes, make C. intestinalis and C. savignyi model organisms for proteomics research. To observe the effect of heat shock, animals of both species were exposed to either a 22˚C, 25˚C, or 28˚C temperature treatment for 6 hours, and then allowed to recover at 13˚C for 16 hours. Two-dimensional gel electrophoresis was employed to separate proteins and create protein expression profiles. We found that 32% of the total protein spots detected for C. intestinalis and 24% of those detected for C. savignyi underwent significant changes in their expression across treatment groups. In order to further characterize the thermal stress response, we used MALDI TOF/TOF mass spectrometry to identify proteins of interest and had a 90% success rate. After comparing the identified proteins across species, we were able to determine that different proteins showed changes in their expression across treatments. This suggests that the thermal stress response differs between these two species. For C. savignyi, the thermal stress response consisted of variations in the expression of cytoskeletal proteins; while C. intestinalis had a more complex response consisting of changes in a wide-range of proteins including chaperones, transport proteins, and metabolic proteins. These interspecific differences in the thermal stress response suggest possible biochemical differences that may lead to variation in thermal tolerance.