Gene Cloning And Function Study Of P26S-8in Zebrafish(Danio Rerio)

Microgravity environment of space can induce a serial of changes in gene and protein expression profilings. Our previous study of simulated-microgravity on zebrafish (Danio rerio) embryos demonstrated P26S-8protein was up-regulated on two-dimensional (2-D) electrophoresis gel, while the gene expression level of p26s-8was significantly decreased after simulated-microgravity. These results suggest that p26s-8may be a microgravity sensitive gene. However, functional study on p26s-8is very limited and it has not been cloned in zebrafish till now.In this study, we tried to clone p26s-8gene in zebrafish, quantify its protein expression level in zebrafish embryos after simulated microgravity, and identify its function in cell cycle regulation. A rotary cell culture system (RCCS) designed by national aeronautics and apace administration (NASA) of America was used to simulate microgravity.The whole sequence of p26s-8gene in zebrafish was cloned in this study for the first time. Preliminary analysis on its sequence and phylogenetic tree construction were carried out subsequently. Quantitative analysis by western blot showed that p26s-8protein expression levels were significantly increased1.18and1.22times after24-48hpf and24-72hpf simulated microgravity, respectively. Moreover, a significant delay on zebrafish embryo development was found in simulated-microgravity exposed group. Inhibition of P26S-8protein in zebrafish embryonic cell lines ZF4could block cell cycle in G1phase, which indicated that p26s-8may play a role in cell cycle regulation. Intererstingly, simulated-microgravity could also lead to the block in the G1. Whether it is p26s-8mediated cell cycle regulation result in the zebrafish embryo development delay after simulated microgravity exposure still needs further study. However, results obtained in this study will contribute to the biological mechanism revealing of microgravity.