The gene fl(2)d is needed for the sex-specific splicing of transformer pre-mRNA but not for double-sex pre-mRNA in Drosophila melanogaster

In Drosophila melanogaster, regulation of the sex determination genes throughout development occurs by sex-specific splicing of their products. The first gene is Sex-lethal (Sri). The downstream target of Sxl is the gene transformer (tra): the Sxl protein controls the female-specific splicing of the Tra pre-mRNA. The downstream target of the gene a a is the gene double-sex (dsx): the Tra protein of females, controls the female-specific splicing of the Dsx pre-mRNA. We have identified a gene, female-lethal-2-d fl (2) d, whose function is required for the female-specific splicing of Sxl pre-mRNA. In this report we analyze whether the gene fl (2) d is also required for the sex-specific splicing of both Tra and Dsx pre-mRNAs. We found that the Sri protein is not sufficient for the female-specific splicing of Tra pre-mRNA, the fl (2) d function also being necessary. This gene; however, is not required for the female-specific splicing of Dsx pre-mRNA.