title: Origin of Chinese goldfish and sequential loss of genetic diversity accompanies new breeds.
abstract: BACKGROUND
  Goldfish, Carassius auratus, have experienced strong anthropogenic selection during their evolutionary history, generating a tremendous extent of morphological variation relative to that in native Carassius. To locate the geographic origin of goldfish, we analyzed nucleotide sequences from part of the control region (CR) and the entire cytochrome b (Cytb) mitochondrial DNA genes for 234 goldfish and a large series of native specimens. Four important morphological characteristics used in goldfish taxonomy-body shape, dorsal fin, eye shape, and tailfin-were selected for hypothesis-testing to identify those that better correspond to evolutionary history.
  
  
  RESULTS
  Haplotypes of goldfish rooted in two sublineages (C5 and C6), which contained the haplotypes of native C. a. auratus from southern China. Values of F(ST) and N(m) revealed a close relationship between goldfish and native C. a. auratus from the lower Yangtze River. An extraordinary, stepwise loss of genetic diversity was detected from native fish to goldfish and from Grass-goldfish relative to other breeds. Significantly negative results for the tests of Tajima's D and Fu and Li's D* and F* were identified in goldfish, including the Grass breed. The results identified eye-shape as being the least informative character for grouping goldfish with respect to their evolutionary history. Fisher's exact test identified matrilineal constraints on domestication.
  
  
  CONCLUSIONS
  Chinese goldfish have a matrilineal origin from native southern Chinese C. a. auratus, especially the lineages from the lower Yangtze River. Anthropogenic selection of the native Carassius eliminated aesthetically unappealing goldfish and this action appeared to be responsible for the stepwise decrease in genetic diversity of domesticated goldfish, a process similar to that reported for the domestication of pigs, rice, and maize. The three-breed taxonomy--Grass-goldfish, Egg-goldfish, and Wen-goldfish--better reflected the history of domestication.
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, the Chinese Academy of Sciences, Kunming, China.
authors.forename: Shu-Yan
authors.initials: SY
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Luo
authors.forename: Robert W
authors.initials: RW
authors.lastname: Murphy
authors.forename: Shi-Fang
authors.initials: SF
authors.lastname: Wu
authors.forename: Chun-Ling
authors.initials: CL
authors.lastname: Zhu
authors.forename: Yun
authors.initials: Y
authors.lastname: Gao
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Zhang
mesh_terms: D063147:Animal Distribution; D058500:Animal Fins / Q000033:anatomy & histology; D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D005075:Biological Evolution; D002681:China; D045303:Cytochromes b / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D005123:Eye / Q000033:anatomy & histology; D014644:Genetic Variation; D006054:Goldfish / Q000033:anatomy & histology / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics; D016013:Likelihood Functions; D019901:Locus Control Region / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D012641:Selection, Genetic; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D045303:Cytochromes b