Expression Analysis Of MRNAs And LncRNAs In Drosophila During Dietary Restriction To Delay Aging

Aging is a process in which the functional integrity of an organism decreases,homeostasis is lost,and eventually death.How to delay aging and explore the mechanism of aging has become an important subject of aging biology.As one of the most effective non-genetic interventions to improve health and extend life,dietary restriction(DR)can improve the aging and aging-related diseases of many invertebrates,rodents,and primates.The combined analysis of transcriptomics and proteomics can help to discover new molecular or mechanisms in DR delaying aging.In this study,we used RNA sequencing to construct and analyze the transcriptome of young(7 d)and old(42 d)Drosophila melanogaster under DR and Ad libitum(AL).The functions of lnc RNA XLOC?076307 was verified at the level of Drosophila S2 cells by RNA interference(RNAi)technology.Besides,we analyzed the relationship between the transcriptome and proteome of DR to delay aging.The main research results were as follows:(1)A total of approximately 86.78 GB of raw reads were obtained from the eight sequencing libraries established in this study.The proportion of filtered reads to raw reads was greater than 95.15%,and more than 83.30% of clean reads can be compared to the reference genome of Flybase.The expression levels of 16 selected transcripts were verified by q RT-PCR,and the results were consistent with the sequencing results.(2)A total of 30413 m RNA transcripts were identified in the DR and AL groups,including 30165 known m RNA transcripts and 248 novel m RNA transcripts.Among the four different comparison groups(DR-7d vs AL-7d,DR-7d vs DR-42 d,AL-7d vs AL-42 d,DR-42 d vs AL-42d),1406 differentially expressed m RNAs were identified.Functional enrichment analysis revealed that the differentially expressed genes were mainly enriched in 70 GO terms including peptidase activity and catalytic activity functions,and 12 KEGG pathways including phototransduction and metabolic pathways.(3)A total of 1860 lnc RNAs were identified in this experiment,including 134 known lnc RNAs and 1726 new lnc RNAs,including long intergenic non-coding RNAs,intron lnc RNAs,and antisense lnc RNAs.Compared with m RNAs,lnc RNAs had lower overall expression level,shorter average length and open reading frame length,and less number of exons.A total of 102 lnc RNAs were differentially expressed in the four comparison groups.Target genes predicted of differentially expressed lnc RNAs are enriched in different GO terms such as heme binding and iron ion binding,involving aging-related signaling pathways such as m TOR,FOXO,and Wnt.(4)Lnc RNA XLOC?076307 had three targets(Hsp70Bc,Gadd45,and Socs36E)by predicting.In Drosophila S2 cells,knocking down XLOC?076307 by si RNA showed the increased expression level of Gadd45 and Socs36 E,compared with decreased Hsp70 Bc expression level.(5)The correlation analysis of transcriptome and proteome identified that more than2700 genes expressed both m RNAs and proteins,but there was a low correlation between the changes in m RNAs and proteins expression levels.In the four pairs of association analysis,there were 11,9,6,and 4 differentially expressed genes with the same m RNA and protein expression trends,and 7,3,10,and 9 differentially expressed genes with the opposite m RNA and protein expression trends,respectively.Genes or proteins with consistent changes in expression levels play an important role in the biological process or signaling pathways,such as metabolism,stress response,determination of adult lifespan,and regulation of autophagy.In summary,dietary restriction extends the lifespan of Drosophila by regulating various m RNA and lnc RNA transcripts and consequently by regulation of downstream target genes or signaling pathways.