title: Extra Microchromosomes Play Male Determination Role in Polyploid Gibel Carp.
abstract: Sex is generally determined by sex chromosomes in vertebrates, and sex chromosomes exhibit the most rapidly-evolving traits. Sex chromosome evolution has been revealed previously in numerous cases, but the association between sex chromosome origin and the reproduction mode transition from unisexual to sexual reproduction remains unclear. Here, we have isolated a male-specific sequence via analysis of amplified fragment length polymorphism from polyploid gibel carp (Carassius gibelio), a species that not only has the ability to reproduce unisexually but also contains males in wild populations. Subsequently, we have found through FISH analysis that males have several extra microchromosomes with repetitive sequences and transposable elements when compared to females. Moreover, we produced sex-reversed physiological females with a male-specific marker by using estradiol hormone treatment, and two gynogenetic families were established from them. In addition, the male incidence rates of two gynogenetic families were revealed to be closely associated with the extra microchromosome number of the sex-reversed physiological females. These results suggest that the extra microchromosomes in males might resemble a common feature of sex chromosomes and might play a significant role in male determination during the evolutionary trajectory of the reproduction mode transition from unisexual to sexual reproduction in the polyploid fish.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Xi-Yin
authors.initials: XY
authors.lastname: Li
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Qi-Ya
authors.initials: QY
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Xiao-Juan
authors.initials: XJ
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Da
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China jfgui@ihb.ac.cn.
authors.forename: Jian-Fang
authors.initials: JF
authors.lastname: Gui
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D000818:Animals; D002347:Carps / Q000235:genetics* / Q000254:growth & development; D002875:Chromosomes / Q000235:genetics*; D005260:Female; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D011123:Polyploidy; D012098:Reproduction / Q000235:genetics*; D019849:Sex Determination Processes / Q000235:genetics*
keywords: genetics of sex; gibel carp; microchromosome; polyploid; sex chromosome; sex determination