Meeting Abstract

18.5  Sunday, Jan. 4  Proteomic Response of the Sea Urchin, Strongylocentrotus purpuratus, Early Cleavage Embryo to Ultraviolet Radiation CAMPANALE, J. P.*; TOMANEK, L.; ADAMS, N. L.; California Polytechnic State Univ., San Luis Obispo; California Polytechnic State Univ., San Luis Obispo; California Polytechnic State Univ., San Luis Obispo jpcampan@calpoly.edu

Increasing solar ultraviolet radiation (UVR, 290-400 nm), especially ultraviolet B, (UVB, 290-320 nm) is reaching Earths surface due to ozone depletion and global climate change. Embryos of the purple sea urchin, Strongylocentrotus purpuratus, provide an ideal system for modeling the protein mediated cell cycle response to stressful UV-irradiation. Six batches of S. purpuratus embryos were exposed to UVR and monitored for delays in mitotic cleavage. Protein expression profiles from UV-treated and UV-protected embryos were obtained using two-dimensional gel electrophoresis (2D GE). Eggs were fertilized, exposed to UVR using a Q-Panel UV-340 lamp and allowed to develop for 30 and 90 mins. Subsequently, proteins were isoelectrically focused (pH 4-7) and separated by molecular weight using SDS-PAGE. UV-treated embryos cleaved an average of 21.69 mins later than the UV-protected embryos. At least 987 protein spots were detected in the gels containing either UV-protected or UV-treated cell lysates. Our preliminary results indicate that 141 protein spots show a significant change in expression density between UV-treatments for all batches of embryos at all time points (2-way ANOVA, P= 0.01). We are evaluating these protein spots for promise as markers of UV-induced stress by identification using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-TOF) mass spectrometry. Our findings indicate that protein expression profiles obtained using 2D GE and MALDI-TOF mass spectroscopy are valuable tools for identifying how embryos respond to UVR -irradiation. Identification of these proteins may allow us to further ascribe functional stress responses at the cellular level.