Effects of simulated-microgravity on development and p53 gene expression of zebrafish embryos

Microgravity can induce a serial of physiological and pathological changes in human body. The mechanism of microgravity-induced bio-effects is one of the most important issues in space studies and still remains unclear. In this research, zebrafish embryo, a powerful model for studying vertebrate development, was exposed to a NASA-designed rotary cell culture system (RCCS) to investigate the effects of simulated-microgravity on development and gene expression. Parameters for development, such as malformation rate, mortality rate, heart rate and body length, as well as p53 gene expression were examined between RCCS-exposed zebrafish embryos and their synchronized controls. The malformation rate, heart rate and body length were all found increased, while no significant change was found on mortality rate after simulated-microgravity exposure. A significant decrease of p53 gene expression was found in 60hpf (hour past fertilization) zebrafish embryos after a 36h simulated-microgravity exposure from 24hpf. Together, our data presented here illustrate that zebrafish embryo can be significantly induced by microgravity on development and gene expression and therefore could be a powerful vertebrate development model for further mechanism study on simulated microgravity.