Transcriptome analysis of 20-hydroxyecdysone induced differentially expressed genes in the posterior silk gland of the silkworm, Bombyx mori

The silk gland is a larval-specific tissue of lepidopteran insects, including silkworm (Bombyx mori).Ecdysteroid is one of the two most important hormones that regulate larval molting and metamorphosis.However, the 20-hydroxyecdysone (20E)-induced gene expression profile in the posterior silk gland (PSG) of silkworm has not been clearly determined.In the present study, the silkworm larvae on the 2nd day of the fifth instar were treated with 20E.The analysis identified 2151, 4385, and 5632 differentially expressed genes (DEGs) at 4 h, 24 h, and 48 h, respectively, after 20E treatment; the downregulated transcripts were more than the upregulated transcripts at all time points.The possible functions of the DEGs were determined using the Gene Ontology (GO) classification system.The Kyoto Encyclopedia of Genes and Genomes (KEGG) database carried out the pathway enrichment analysis.Furthermore, few selected DEGs were verified by quantitative real-time PCR (qRT-PCR).Thus, the present study generated extensive transcriptome and DEG profiling data using the PSG of the 20E-fed silkworm, which provided comprehensive gene expression information at the transcriptional level.The study provides a comprehensive view of the molecular basis of gene regulation by 20E in silkworm PSG.