Musca domestica Genome sequencing and assembly
The housefly (Musca domestica) has a polymorphic sex determination system. Typically, maleness is induced by a dominant male-determining locus M that is needed to break the autoregulatory splicing loop of the female-promoting transformer (tra) gene to allow for male development. M locus can be located not only on the Y-chromosome but also on any of the five autosomes or even on the X-chromosome. The autosomal M-loci and the M-locus on the Y-chromosome may be of recent origin. Recently, the Musca domestica male determiner (Mdmd) gene, which is a paralogue of the generic splice factor gene nucampholin (Mdncm), has been identified as a male-determining gene of the housefly. Mdmd is present in M-loci on autosomes II (MII), III (MIII), and V (MV), and the Y-chromosome (MY). The M-locus on autosome I, however, contains a different male-determining gene which remains unknown. The structures of the various Mdmd-containing M-loci are both diverse and complex, providing a unique opportunity to investigate the primary evolution of sex-determining regions and sex chromosomes. In this BioProject, we characterize the genomic organization of various Mdmd-containing M-loci in the housefly to gain a better understanding of its polymorphic sex determination system.