Cloning and functional characterization of the intersex homologous gene in the pest lepidopteron Maruca vitrata

The intersex (ix) gene works in concert with doublesex (dsx) at the bottom of the sex-determination hierarchy to control somatic sexual differentiation in Drosophila melanogaster females. Here we report the isolation and characterization of the Drosophila intersex (ix) homologue in the pest lepidopteron Maruca vitrata (Mvix). The Mvix gene exhibits major complexity with respect to the Drosophila homolog. It is expressed in males and females and its pre-mRNA is subject to differential splicing events which affect both the protein coding and the non-coding regions. Moreover, Northern blot experiments revealed the presence of a female-specific transcript in pupae RNA, which appears to be the first described sex specific transcript of ix homologs characterized to date. The expression of Mvix cDNA in D. melanogaster transgenic flies indicates that the MvIX product, which shares a relatively high degree of homology with the D. melanogaster IX protein, is able to partially rescues the Drosophila mutant phenotype.