Figure 1. DM domain genes in metazoan sexual development.
a | Metazoan phylogeny showing phyla in which DM domain genes have been implicated in sexual development, either through functional analysis or sex-biased expression (highlighted in red). b | Arthropod phylogeny showing taxa in which a doublesex (dsx) gene has been shown to be required for sexual differentiation (highlighted in red). Sex-determining mechanisms of species shown to require dsx are indicated by the letters placed next to the name of the taxon. Note that many other sex-determining mechanisms are found in most of these taxa but are not known to involve a dsx-like gene. c | Vertebrate phylogeny showing taxa in which a Dmrt1 homologue is required for sex determination (highlighted in red). In teleost fish and in amphibians, many other sex-determining mechanisms occur, but the role of Dmrt1 is unknown in most of these. ESD, environmental sex determination; HD, haplodiploid system in which females are haploid (from unfertilized eggs), and males are diploid (from fertilized eggs); XY, male heterogamety with XY males and XX females; ZW, female heterogamety system with ZZ males and ZW females.
