The Function Study Of RNA M~6A Demethylase ALKBH5 In The Development Of Mouse Cerebellum

N6-methyladenosine(m6A)is installed by methyltransferases(METTL3,METTL14,WTAP),and reversed by demethylases(ALKBH5,FTO).m6A is an important epitranscriptomic mark with high abundance in the brain.Recently,it is found to be involved in the regulation of memory formation and mammalian cortical neurogenesis.Our previous work identify that m6A is unique in mouse cerebellum.However,the functions of m6A in mouse cerebellar development still await elucidate.Given that the level of m6A is correlated with methyltransferases and demethylases,here we show the spatiotemporal-specific expression of m6A writers(METTL3,METTL14 and WTAP)and erasers(ALKBH5 and FTO)in the mouse cerebellum.The expression of these enzymes is decreasing during the mouse cerebellar development.Given the spatiotemporal expression of ALKBH5 in the mouse cerebellum,we next test its role in cerebellar development.Compared to that of wild-type mice,the cerebellum of Alkbh5-knockout mouse lacks any detectable changes in its weight and morphology.To overcome compensatory mechanism,we use Alkbbh5-deficient mice exposed to hypobaric hypoxia for further study.Under hypobaric hypoxia exposure,Alkbh5-deletion causes abnormal cell proliferation and differentiation in the cerebella through disturbing the balance of RNA m6A methylation in different cell fate determination genes.Notably,nuclear export of the hypermethylated RNAs was enhanced in the cerebellum of Alkbh5-deficient mice exposed to hypobaric hypoxia.The results indicate that ALKBH5 plays an important role in mouse cerebellar devopment by regulating RNA export.Our previous results identify the widespread and dynamic RNAm6A methylation in the developing mouse cerebellum,and further uncover the distinct features of continuous and temporal-specific m6A methylation across the four postnatal developmental processes.In addition,our previous results indicate that ectopic expression of METTL3 mediated by lentivirus infection leads to disorganized structure of both Purkinje and glial cells.Together,our findings provide strong evidence that RNAm6A methylation is controlled in a precise spatiotemporal manner and participates in the regulation of postnatal development of the mouse cerebellum.