Novel female-specific trans-spliced and alternative splice forms of dsx in the silkworm Bombyx mori

► Trans-splicing is a novel splicing method of Bmdsx. ► Six novel trans-spliced variants of Bmdsx have been found. ► A novel exon and a novel female-specific splice form BmdsxF3 have been found. ► Novel additional gene dsr2 suppresses the BmdsxF mRNA translation. ► Ectopic expression of BmDSXF3 could repress the PBP and tsA2 genes in males.