Transcriptomic analysis of Drosophila imaginal wing discs cultured in insulin or 20-hydroxyecdysone

ABSTRACT: We identified a role for low concentrations of 20-hydroxyecdysone (20E) in promoting growth of the Drosophila larval wing imaginal disc using genetics and in vitro explant culture. We found that 20E alone could promote proliferation in the absence of added insulin, a well known regulator of growth. To investigate the mechanism by which these hormones promote growth, we sequenced the transcriptomes of mid-third instar wing discs cultured in no hormone, 20E alone or insulin alone at two timepoints (4hr and 9hr). We also sequenced the transcriptomes of freshly dissected wing discs (not cultured). We found that within 4hr of culture without hormone, the expression of 1604 genes goes down and 1409 genes goes up, relative to uncultured discs. Changes in the expression of 1911 genes could be prevented, at least transiently, by the addition of either 20E or insulin. The transcriptional response to insulin was remarkably transient, decreasing by rougly 50% from 4hr to 9hr of culture. The response to 20E was smaller than that induced by insulin, but longer lasting. Insulin-induced genes are most significantly enriched in GO-terms describing DNA replication, ribosome biogenesis, translation, purine biosynthesis, and mitochondrial biogenesis. Insulin-repressed genes are enriched in genes involved in autophagy and cell death. 20E-regulated genes were also enriched for genes involved in DNA replication. Unlike insulin, however, 20E was found to promote the expression of genes in GO categories describing a variety of developmental processes. These data represent the first description of the direct transcriptional response of the wing disc to either insulin or low doses of 20E.

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE92933 | GEO | 2017/11/01

SECONDARY ACCESSION(S): PRJNA359106

REPOSITORIES: GEO