Cartilaginous fish Elasmobranchii 3 Article 2 Callorhinchus milii 2 Evolution 2 GnRH gene 2 GnRH1 gene 2 GnRH1a gene 2 GnRH1b gene 2 GnRH2 gene 2 GnRH3 gene 2 Gonadotropin-releasing hormone 2 Holocephali 2 Multigenic family 2 Neuropeptides 2 Rhincodon typus 2 Scyliorhinus canicula 2 Vertebrates 2 animal tissue 2 cartilaginous fish 2 controlled study 2 diencephalon 2 enzyme activity 2 female 2 gene 2 gene dosage 2 gene expression 2 gene identification 2 gene structure 2 genetic trait 2