BmBlimp-1 gene encoding a C2H2 zinc finger protein is required for wing development in the silkworm Bombyx mori

Cys2-His2 zinc finger (C2H2-ZF) proteins represent the most common class of transcription factors. These factors have great potential for the management of developmental progression by regulating the specific spatiotemporal expression of genes. In this study, we cloned one C2H2-ZF protein gene of , , that is orthologous to ( ); we thus named it as ( ). In the silkworm, the gene is specifically upregulated during day 2 of the pupal to adult stage and is highly expressed in wing discs on day 3 of the pupa. Knockdown of its expression level in the pupal stage results in a crumpled-winged silkworm moth. Using the predicted DNA-binding sequences of to search the silkworm genome to screen target genes of , 7049 genes were identified to have at least one binding site of on their 1 kb upstream and downstream genome regions. Comparisons of those genes with a reported pupal wing disc transcriptome data resulted in 4065 overlapping genes being retrieved. GO enrichment analysis of the overlapping genes showed that most of the genes were enriched in the binding term. Combining functional annotation and real-time quantitative PCR, 15 genes were identified as the candidate target genes of , including several wing cuticular protein genes, , and wing disc development genes, such as , ( ) and ( ). Moreover, the amino acid sequence of the zinc finger motif of gene was highly conserved among the 15 insect species. We propose that is an important regulatory factor in silkworm wing development.