Day-by-day analysis of whole midgut transcriptome profiles in untreated and early injured Drosophila from young to old. (PRJCA026790)

Purpose: Our previous data showed that injury to the young midgut (early injury) prevents the abrupt onset of age-related hyperplasia in old flies and extends their lifespan. To identify the mechanism by which abrupt age-related hyperplasia occurs in the midgut of untreated (UT) flies and is alleviated by early injury (EI). We sequenced the midgut of UT and EI flies daily from 4d to 28d using Illumina NovaSeq 6000 and performed RNA-seq analysis. Results: We found that a large proportion of genes in the midgut of UT flies changed abruptly at 19 days, including genes related to EC replacement, immune response and mitotic cell cycle, consistent with the abrupt onset of hyperplasia. Significantly, these gene expressions were not abruptly changed in EI ageing flies. Our data confirm the abruptness of Drosophila intestinal ageing at the level of global gene transcription. It is suggested that the abruptness of intestinal ageing is due to a dramatic turnover of ECs that occurs at around 19 days.