title: Autotriploid origin of Carassius auratus as revealed by chromosomal locus analysis.
abstract: In the Dongting water system, the Carassius auratus (Crucian carp) complex is characterized by the coexistence of diploid forms (2n=100, 2nCC) and polyploid forms. Chromosomal and karyotypic analyses have suggested that the polyploid C. auratus has a triploid (3n=150, 3nCC) and a tetraploid origin (4n=200), respectively. However, there is a lack of direct genetic evidence to support this conclusion. In this paper, analysis of the 5S rDNA chromosomal locus revealed that the 3nCC is of triploid origin. Analysis of the species-specific chromosomal centromere locus revealed that 3nCC individuals possess three sets of C. auratus-derived chromosomes. Our results provide direct cytogenetic evidence suggesting that individuals with 150 chromosomes are of autotriploid origin within the C. auratus complex. It marks an important contribution to the study of polyploidization and the evolution of vertebrates.
authors.affiliation: Key Laboratory of Protein Chemistry and Fish Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
authors.forename: Qinbo
authors.initials: Q
authors.lastname: Qin
authors.affiliation: Key Laboratory of Protein Chemistry and Fish Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Protein Chemistry and Fish Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
authors.forename: Min
authors.initials: M
authors.lastname: Hu
authors.affiliation: Key Laboratory of Protein Chemistry and Fish Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
authors.forename: Shengnan
authors.initials: S
authors.lastname: Huang
authors.affiliation: Key Laboratory of Protein Chemistry and Fish Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha, 410081, China. lsj@hunnu.edu.cn.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Liu
mesh_terms: D000818:Animals; D002347:Carps / Q000235:genetics*; D002874:Chromosome Mapping; D017404:In Situ Hybridization, Fluorescence; D057885:Triploidy
keywords: autotriploids; chromosomal loci; evolution; polyploidization