Differentially expressed genes in the ovary of the sixth day of pupal "Ming" lethal egg mutant of silkworm, Bombyx mori

Abstract

The "Ming" lethal egg mutant (l-em) is a vitelline membrane mutant in silkworm, Bombyx mori. The eggs laid by the l-em mutant lose water, ultimately causing death within an hour. Previous studies have shown that the deletion of BmEP80 is responsible for the l-em mutation in silkworm, B. mori. In the current study, digital gene expression (DGE) was performed to investigate the difference of gene expression in ovaries between wild type and l-em mutant on the sixth day of the pupal stage to obtain a global view of gene expression profiles using the ovaries of three l-em mutants and three wild types. The results showed a total of 3,463,495 and 3,607,936 clean tags in the wild type and the l-em mutant libraries, respectively. Compared with those of wild type, 239 differentially expressed genes were detected in the l-em mutant, wherein 181 genes are up-regulated and 58 genes are down-regulated in the mutant strain. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis results showed that no pathway was significantly enriched and three pathways are tightly related to protein synthesis among the five leading pathways. Moreover, the expression profiles of eight important differentially expressed genes related to oogenesis changed. These results provide a comprehensive gene expression analysis of oogenesis and vitellogenesis in B. mori which facilitates understanding of both the specific molecular mechanism of the 1-em mutant and Lepidopteran oogenesis in general.

Keywords: 19.5-kDa heat shock protein; 20-hydroxy-ecdysone; 20E; Bombyx mori; DGE; Digital gene expression; EO; Ecdysone; Ecdysone oxidase; FDR; False discovery rate; GO; Hsp19.5; KEGG; Lethal egg mutant; SilkDB; Silkworm genome database; Some small Hsps; TPM; The Kyoto Encyclopedia of Genes and Genomes; The gene ontology; The quantitative real-time PCR method; The “Ming” lethal egg mutant; Transcripts per million clean tags; VMPs; Vitelline membrane protein; Vitelline membrane proteins; l-e(m); qRT-PCR; sHSP; sHsps.