ASGSB 1999 Annual Meeting Abstracts

CELLULAR GENE EXPRESSION IN RESPONSE TO MICROGRAVITY AND VIBRATIONAL STRESS. L.A. Cubano and M.L. Lewis. Dept. of Biological Sciences, Univ. of Alabama in Huntsville.

RNA from Jurkat cells flown on the Space Shuttle mission STS-95, was extracted and used in a microarray test to determine gene expression compared to ground controls. We also subjected cells to vibrational stress to distinguish between genes expressed in response to simulated launch vibration compared to spaceflight. These analyses served to further support our previous observation of time-related changes in the cytoskeleton and the apparent return to normal morphology during spaceflight (Lewis 1998). RT-PCR was performed to verify the expression of cytoskeletal genes found by microarray and to further evaluate the effects of vibration on gene expression. The RT-PCR confirmed the results of the microarrays and only slight differences in magnitude of genes expressed were noted for actin, tubulin , tubulin , and actinin. The presence of plectin was also confirmed. Plectin and its isoforms are versatile cytoskeletal linker proteins associated with all three cytoskeletal filament networks and subplasma membrane skeleton proteins. These proteins play an important role in cytoskeletal network organization. Plectin up-regulation is compatible with the idea of cytoskeletal reorganization after disruption by conditions of spaceflight. Now we report an increased expression of mRNA encoding for cytoskeletal proteins, including plectin and tropomodulin, providing further evidence of cytoskeletal rearrangement in microgravity.

This research was supported in part by NASA Grants NAG2-985 and 97-GSRP-076

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