A Powerful Vertebrate Development Model For Simulated Microgravity Study

Microgravity environment of space can induce a serial of physiological and pathological changes in human body, such as cardiovascular functional disorder, bone loss, muscular atrophy and impaired immune system function, etc. The mechanism of microgravity-induced biological effects is one of the most important issues in space biological studies. Researches carried on space were seriously limited by many factors, such as rare chances for flight, bio-security risks and volume/weight limitation. Therefore, a more accessible ground platform is urgently needed for microgravity-related study. In this research, we focus on the influence of microgravity to vertebrate embryo development. A powerful vertebrate development model for simulated-microgravity-induced bio-effects study has been established.In this paper, zebrafish(Danio rerio) embryos at different development stages were exposed to simulated microgravity, respectively, using rotary cell culture system (RCCS) designed by national aeronautics and apace administration (NASA) of America. Protein profilings of treated and control embryos were analyzed by two-dimensional (2-D) gel electrophoresis. Image analysis of silver stained 2-D gels revealed 28 protein spots showed significant variations (P≤0.05) between simulate-microgravity treated and stationary control samples, quantitatively and qualitatively. Ten of those spots were excised from 2-D gels and analyzed by MALDI-TOF/TOF mass spectra primarily. Results demonstrated these proteins were closely related to cell structure, muscle composition and energy metabolism. Since some of the proteins have never been reported in microgravity-related study, the method we established here seems to be a powerful tool to reveal more target molecules induced by microgravity.For further investigation of microgravity effect on protein expression and regulation, corresponding mRNA expression levels of four sequenced proteins (creatine kinase muscle B, actin cytoplasmic 2, centrosomal protein 135KD, tropomyosin 4) and apoptosis-related p53 protein, were selected for measurement by quantitative PCR (RT-qRCR). The response time of above target molecules to simulated microgravity was obtained. Expression profiles of above genes depended on the development stages of embyoes exposed to simulated microgravity and the exposure time.