Open and closed evolutionary paths for drastic morphological changes, involving serial gene duplication, sub-functionalization and selection

• Published in: Scientific reports Vol. 6; no. 1; p. 26838
• Main Authors: Abe, Gembu, Lee, Shu-Hua, Li, Ing-Jia, Chang, Chun-Ju, Tamura, Koji, Ota, Kinya G.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 25.05.2016; Nature Publishing Group
• Subjects: 38/23; 38/71; 38/77; 631/136/1660; 631/181/2806; Animals; Biological Evolution; Carp; Carps - embryology; Carps - genetics; Chordin; Chordin gene; Domestication; Gastrula - metabolism; Gene Duplication; Gene expression; Gene Expression Regulation, Developmental - drug effects; Glycoproteins - genetics; Glycoproteins - physiology; Goldfish - anatomy & histology; Goldfish - embryology; Goldfish - genetics; Humanities and Social Sciences; In Situ Hybridization; Intercellular Signaling Peptides and Proteins - genetics; Intercellular Signaling Peptides and Proteins - physiology; Morpholinos - pharmacology; Morphology; multidisciplinary; Mutation; Phenotype; Phylogeny; Science; Species Specificity; Tail - embryology; Tail - ultrastructure; Tails
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep26838

Twin-tail goldfish strains are examples of drastic morphological alterations that emerged through domestication. Although this mutation is known to be caused by deficiency of one of two duplicated chordin genes, it is unknown why equivalent mutations have not been observed in other domesticated fish species. Here, we compared the chordin gene morphant phenotypes of single-tail goldfish and common carp (close relatives, both of which underwent chordin gene duplication and domestication). Morpholino-induced knockdown depleted chordin gene expression in both species; however, while knockdown reproduced twin-tail morphology in single-tail goldfish, it had no effect on common carp morphology. This difference can be explained by the observation that expression patterns of the duplicated chordin genes overlap completely in common carp, but are sub-functionalized in goldfish. Our finding implies that goldfish drastic morphological changes might be enhanced by the subsequent occurrence of three different types of evolutionary event (duplication, sub-functionalization and selection) in a certain order.