Masculinizer-induced dosage compensation is achieved by transcriptional downregulation of both copies of Z-linked genes in the silkworm, .

The evolution of dosage compensation produces similar expression of sex-linked and autosomal genes in the heterogametic sex. The silkworm (), a lepidopteran insect, has a female heterogametic WZ sex determination system. A Z-linked gene, (), is the primary determinant of maleness and dosage compensation in . However, it remains unknown whether one of the two Z chromosomes is inactivated or both Z chromosomes are suppressed in males. Hence, we performed transcriptome analysis using hybrids between two strains and analysed allele-specific expression to distinguish these alternatives. Our analysis revealed that genes on both the maternal and paternal Z chromosomes are transcriptionally upregulated in knocked down males. We therefore conclude that both Z chromosomes are transcriptionally downregulated in males, similar to the system in .