Long non-coding RNAs (lncRNAs) have been suggested to play important roles in some biological processes. However, the detailed mechanisms are not fully understood. We previously identified an antisense lncRNA, Bmdsx-AS1, that is involved in pre-mRNA splicing of the sex-determining gene Bmdsx in the silkworm. In this study, we analyzed the changes in the male external genitalia of transgenic overexpressed Bmdsx-AS1 silkworm lines and analyzed downstream and upstream responses. We found that Bmdsx-AS1 transgenic silkworms, compared with wild type, showed more claspers in the male external genitalia. Quantitative real-time PCR (qPCR) results indicated that overexpression of Bmdsx-AS1 decreased the expression of genes in the EGFR signaling pathway. Knockdown of Bmdsx-AS1 increased the activity of the EGFR pathway. Through promoter prediction, promoter truncation and electrophoretic mobility shift assay (EMSA) analyses, we found that the protein encoded by the Hox gene BmAbd-B specifically binds to the promoter of Bmdsx-AS1. Moreover, overexpression of BmAbd-B in the silkworm BmE cell line indicated that BmAbd-B negatively regulates the mRNA expression of Bmdsx-AS1. Our study provides insights into the regulatory mechanism of the lncRNA in the silkworm.
Keywords: BmAbd-B; Bmdsx-AS1; EGFR signaling; external genitalia; lncRNA; silkworm.