Investigating The Role Of AMX-1 In Caenorhabditis Elegans

The integrity of genetic information is very important for organisms.DNA damages come from endogenous metabolites or various external factors,such as ultraviolet rays,radioactive substances and chemicals.Because DNA damage hinders the transmission of genetic information over generations,the repair mechanism called "DNA damage response and repair" in cells must repair these damages in time so that the correct genetic information can be transmitted when DNA is replicated.Both SPR-5 and AMX-1 are homologous proteins of human histone demethylase LSD1/2.Previous studies have shown that the Caenorhabditis elegans(C.elegans)histone demethylase SPR-5 is involved in the DNA damage response,but the mechanism by which SPR-5 performs this function remains to be explored.This study investigated the function of AMX-1 by performing plate phenotype analysis,sterility assay,germ cell apoptosis analysis,immunofluorescence microscopy and DNA damage sensitivity assay.We found that: AMX-1 is required for a normal brood size and sterility regardless of generations,and unlike in spr-5(by101)mutant,the defect of fertility(brood size and sterility)is not progressive.Interestingly,the sterility in amx-1(ok659)mutant is dependent on p53/CEP-1,while sterility in spr-5(by101)mutant is not p53/CEP-1dependent,hinting in independency of AMX-1 and SPR-5 function in fertility in germline.A higher level of unrepaired double strand breaks and apoptosis suggest that unrepaired damages converted to apoptosis.The elevated level of apoptosis and RAD-51 suggests the potential DNA damage repair function of AMX-1.All these findings provide new ideas for the future understanding of the role of histone epigenetic regulation in DNA damage repair.