Sex dimorphic expression of five dmrt genes identified in the Atlantic cod genome. The fish-specific dmrt2b diverged from dmrt2a before the fish whole-genome duplication

Transcriptional variants of Dmrt1 and expression of four Dmrt genes in the blunt snout bream, Megalobrama amblycephala

“…In fish, Dmrt2 is called Dmrt2a, and the fish-specific Dmrt2b is supposed to be duplicated from Dmrt2 during the third round of ray-finned fish specific genome duplication around 350 Ma ago . Limited information show that Dmrt2b is absent in the Atlantic cod (Gadus morhua) or non-functional in the Japanese pufferfish (Takifugu rubripes) (Johnsen and Andersen, 2012;Yamaguchi et al, 2006). Dmrt2b knockdown embryos display a downward tail curvature in the zebrafish (Danio rerio) (Liu et al, 2009).…”

“…Previous studies show that in both the chicken and mouse embryo, Dmrt3 was expressed primarily in the developing forebrain and neural tube (Smith et al, 2002). In teleost, the medaka and pufferfish Dmrt3 display malespecific gonad expression, whereas the zebrafish and Atlantic cod Dmrt3 are expressed in both male and female gonads (Brunner et al, 2001;Veith et al, 2006;Yamaguchi et al, 2006;Johnsen and Andersen, 2012).…”

The roles of Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes in sex determination and differentiation mechanisms: Ubiquity and diversity across the animal kingdom

“…Dmrt2 (also named Terra gene) implicated in neurogenesis [78] and left-right patterning [79] during embryonic development, while it is mainly expressed in male and female gonads or gills in adult fish. Exclusively, female expression has been identified in the gonad of the Atlantic cod [77]. In contrast, Dmrt3 has presented clearly male-gonad-biased expression in all studied species (Table 3).…”

“…Temporally, all of these genes are active during both embryogenesis and various adult physiological processes [74,[77][78][79][80][81][82][83][84][85]. Dmrt2 (also named Terra gene) implicated in neurogenesis [78] and left-right patterning [79] during embryonic development, while it is mainly expressed in male and female gonads or gills in adult fish.…”

“…Such bias was also detected in other organs of the Japanese pufferfish, prompting the authors to propose that Dmrt3 functions cooperatively with Dmrt1 after gonadal differentiation in both fishes and mammals [82]. The gonadal sex-specific expression of Dmrt4 varies by species: in the Tilapia (Oreochromis aureus), Dmrt4 is only expressed in the ovary [83,85]; in the olive flounder (Paralichthys olivaceus) and the Medaka fish, it is only expressed in the testis [80,84]; and in the Atlantic cod and the Japanese pufferfish, it is expressed in the ovary and testis [77,82].…”