The Search For Identification Of Target Genes Involved In DFoxo-mediated Lifespan Extension In Drosophila

As a member of the large Forkhead transcription factors family of proteins,Foxo participates in a number of important signaling pathways and mediates transcriptional expression of downstream target genes,which plays an important role in a number of important biological processes such as cell differentiation,cell metabolism and cell apoptosis.Meanwhile,Foxo is a key molecule of IIS(Insulin / IGF)signaling pathway by phosphorylation of upstream Insulin signaling cascade pathway regulation mediated expression of downstream target genes involved in the biological process of aging.Study on upstream signaling pathways regulating Foxo life has been a lot,but the transcriptional regulation mechanism of downstream target genes of Foxo is still unclear.In this paper,we use the model organism Drosophila melanogaster to screen the potential transcriptional regulation gene of Foxo,and study the mechanism that how the Foxo regulates the lifespan of Drosophila melanogaster.Based on the GAL4 / UAS binary expression system,we use RU486 to induce d Foxo overexpress in adult Drosophila fatbody,then carry on hybridization genetic screening by crossing with 30 different gene deletions wild-type flies strains on chromosome 3 of Drosophila.The result was anylysed by Kaplan-Meier survival curves comparing with the lifespan of Foxo overexprsess in wild background.To determine downstream target genes present in the gene fragments according to the Log-Rank analysis.Select the above gene deletions flies into repeatability experiment which affect d Foxo longevity,and some deletions may be screened further to seleck out the most potential deletion fragments.Overexpression of Foxo in adult Drosophila fatbody extends lifespan.When cross with gene deletion strains 3486,6962,7633,7634,7647,7675,7676,7731,7739,8029,8923,8964,9002,9090,9204,9482,9497,9983,24373,24970,24980,24990,24993,25011,25019,25126,26846,26848,27342 and 27580,the prolonged lifespan was inhibited by the male gene deletion strains in all offsprings of 7633,6962,7676,7647,8964,9482,27362 and 24990 flies.Female flies except strains 7647 and 9482 also have the same phenotype,and the gene deletion strains 7633 and 24990 are the most obvious.On the contrary,gene deletion strains 24993,25011 and 27580 extended the lifespan on its basis.Strains 3684,7634,7675,7731,7739,8029,8923,9002,9090,9204,9497,9983,24373,24970,24980,26848,25019,25126 and 26846 caused no effect on the extension lifespan of d Foxo overexpression.Then carrying on to filter gene deletions strain 24990 through hybridization screening,which contains 10 small fragments of gene deletion strains 6164,7645,7646,7647,7932,7970,7972,7974,9087 and 25690,among these strains,the fragments of gene deletion strains 9087,7970,7974 and 25690 were found that inhibited the life-prolonging effect of d Foxo overexpression.Potencial downstream target genes of Foxo may present in deletion Df(3R)Exel6166?Df(3R)Exel8158?Df(3R)ED5610 and Df(3R)BSC615 gene fragment.The study results reveal gene regulation Foxo life to provide data support,and provide theoretical clues for further research on understanding the nature of aging and aging-related diseases.