The decapod researcher’s guide to the galaxy of sex determination

Sex determination systems in Animalia encompass a diverse array of genes, functioning in complex regulatory networks. This diversity is even pronounced within taxonomic ranks and the crustacean Order Decapoda is no exception. The commercial importance of the decapods and the ambition to develop their potential in aquaculture has resulted in the necessity to better understand the processes of sexual development. However, due to a lagging understanding of the regulation of sex determination, systems characterised in other model species often serve as the basis for these investigations. This work presents a collated summary of the current information of sex determination in Decapoda, including all determined chromosomal mechanisms and identified “sex-regulator” homologues, often focussing on genes characterised in the model arthropod Drosophila melanogaster (namely Sxl, Tra, Tra-2, Fru and Dsx), the nematode Caenorhabditis elegans (Fem-1 and Mab-3) and Mammalia (Sry, Sox9, Foxl2 and Dmrt1). Although homologue analyses such as these offer a good method to guide investigations in non-model species, the low conservation and variability of sex determination systems cautions against the assumption of conserved functionality. Thus, we propose a better suited approach to guide studies into sex determination in Decapoda, primarily relating to the functionally conserved sex regulators, the Dmrts.