Meeting Abstract

P3.71  Tuesday, Jan. 6  Environmental Proteomics: Acute salinity stress in the marine model organism Ciona savignyi. KOMAN, James, S*; TOMANEK, Lars; California Polytechnic Univ., San Luis Obispo jskoman@gmail.com

The ascidian Ciona savignyi, a model marine invertebrate organism, was exposed to hyposaline conditions to analyze tolerance toward hyposaline stress. C. savignyi is a species of sea squirt commonly found on pilings of harbors and marinas in the northeast Pacific. Heavy winter rains and subsequent run-offs expose C. savignyi to changing salinity conditions. C. savignyi is an ideal organism for study as its genome has been sequenced and annotated, and as a chordate it is a close relative to vertebrates. Tracking the global changes in protein expression in C. savignyi is a pivotal step in describing the physiological processes that protect animals against cellular damage in response to acute salinity stress. The organisms were exposed to decreasing salinities, 100%, 85% and 70% (sea water), for 6 hours. After exposure to hyposaline conditions, specimens were brought back to 100% salinity to recover for 4 hours. Organisms were dissected to remove the tunic, and 2D SDS-polyacrylamide gel electrophoresis was performed on the whole organism to separate proteins and generate protein expression profiles. Gels were scanned and analyzed with a 2D gel image analysis software (Delta2D, DECODON) to compare expression levels of proteins between treatment groups and the control (100% sea water). Comparisons using a 1-way ANOVA with a p-value of 0.05 led to the identification of 19 spots divided among three activity clusters. It is hypothesized that these proteins play a role in the tolerance toward hyposaline stress in C. savignyi. Further analysis with MALDI TOF-TOF mass spectrometry will allow for the identification of these proteins and help us determine which role they play in the physiological response to decreasing salinity.