Fish specific duplication of Dmrt2: Characterization of zebrafish Dmrt2b

Left-Right Function of dmrt2 Genes Is Not Conserved between Zebrafish and Mouse

“…Recently, it was reported that, due to this genome duplication event, zebrafish dmrt2a/terra has a paralog gene named dmrt2b [37]. Contrary to dmrt2a/terra , that is present in all vertebrates, dmrt2b duplication only exists in the fish genome (zebrafish, tilapia, takifugu, tetraodon, medaka and stickleback), probably due to the fish lineage specific genome duplication [38]. In clear contrast to dmrt2a/terra , the fish-specific duplicated dmrt2b contributes to Hedgehog pathway [37].…”

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

“…In pufferfish, dmrt2b expression was not detected at any larval or adult stages and may be a pseudogene (Yamaguchi et al, 2006). The teleost dmrt2a and dmrt2b paralogs are thought to have separated from an ancestral dmrt2, and the identification of linked genes shared by zebrafish dmrt2a and dmrt2b suggested that the dmrt2 duplication was part of the fish whole-genome duplication (Zhou et al, 2008). However, both dmrt2a and dmrt2b and paralogs of the flanking genes shared very low sequence homology, and a phylogenetic analysis of vertebrate dmrt genes revealed that dmrt2a and dmrt2b are at much more divergent positions than expected in the case of the third round (3R) of genome duplication (Volff et al, 2003).…”

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

“…Dmrt2b knockdown embryos display a downward tail curvature in the zebrafish (Danio rerio) (Liu et al, 2009). In addition, the DMA (DmrtA motif) domain subfamily including Dmrt3, Dmrt4 and Dmrt5, has been detected in the central nervous system and plays a role in nasal placodes in vertebrate (Bellefroid et al, 2013;Smith et al, 2002;Winkler et al, 2004;Veith et al, 2006;Zhou et al, 2008;Huang et al, 2005b). 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).…”

“…To date, many Dmrt (Doublesex and Mab3 related transcription factor) genes have been cloned from a wide variety of both vertebrates and invertebrates, generating 8, 7, 6, 4 and 11 Dmrt genes in the human (Homo sapiens), mouse (Mus musculus), fish, D. melanogaster and C. elegans genome, respectively (Ottolenghi et al, 2002;Kim et al, 2003;Kondo et al, 2002;Zhou et al, 2008;Brunner et al, 2001;Lints and Emmons, 2002). Among these Dmrts, Dmrt1 plays a role in the gene-regulatory cascade system, triggering sexual determination and gonadal differentiation processes in the animal kingdom.…”