An antisense lncRNA functions in alternative splicing of Bmdsx in the silkworm, Bombyx mori.

Long non-coding RNAs (lncRNAs) are recently thought to play important roles in some physiological processes. In this study, we identified a lncRNA (named as Bmdsx-AS1) which is the antisense transcript and locates on the position of the crucial sex-determining gene Bmdsx in the silkworm. Quantitative real-time PCR and Fluorescence in situ hybridization demonstrated that Bmdsx-AS1 was highly expressed in the silkworm testis. After knock-down of Bmdsx-AS1, the splicing pattern of Bmdsx pre-mRNA was altered in male silkworm. Transgenic overexpression of Bmdsx-AS1 indicated male-specific splicing form of Bmdsx arose in female silkworm. Furthermore, by using RNA-protein pull down, LC-MS/MS and EMSA, we found a splicing factor hnRNPH binding specifically to Bmdsx-AS1. Co-Immunoprecipitation suggested that hnRNPH interacted with BmPSI, one of the upstream regulating factors of Bmdsx. Thus, our results suggested that the antisense lncRNA Bmdsx-AS1 was involved in alternative splicing of Bmdsx in the silkworm.