Phylogeny and sex-determination systems in vertebrates. (a) Tetrapods; (b) teleost fishes. The different sex-determination systems found in the different lineages are indicated on the right of the figure. For the fish lineages (b), homologies of identified sex chromosomes to the ancestral teleost karyotype (TEL) are shown . See Table 2 for details.
Marshall Graves and Peichel Genome Biology 2010 11:205 doi:10.1186/gb-2010-11-4-205