Extra Microchromosomes Play Male Determination Role in Polyploid Gibel Carp
Extra Microchromosomes Play Male Determination Role in Polyploid Gibel Carp
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额外微染色体在多倍体银鲫中起雄性决定作用
DOI：
10.1534/genetics.115.185843
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发表时间：
2016-07-01
期刊：
影响因子：
3.3
通讯作者：
Gui, Jian-Fang
中科院分区：
文献类型：
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作者：
Li, Xi-Yin;Zhang, Qi-Ya;Gui, Jian-Fang
脊椎动物的性别通常由性染色体决定，而性染色体表现出进化最快的特征。性染色体的进化已经在许多案例中被揭示出来，但是性染色体起源和从单性生殖到有性生殖的生殖模式转变之间的关联仍然不清楚。在这里，我们已经分离出一个男性特定的序列，通过分析扩增片段长度多态性的多倍体银鲫（银鲫），一个物种，不仅具有单性生殖的能力，但也包含男性在野生种群。随后，我们通过FISH分析发现，与女性相比，男性有几个额外的微染色体重复序列和转座因子。此外，我们还利用雌激素处理，获得了具有雄性特异性标记的生理性逆转雌性，并由此建立了两个雌核发育家系。此外，两个雌核发育家系的男性发病率与性反转生理雌性的额外微染色体数目密切相关。这些结果表明，额外的小染色体在男性可能类似于性染色体的共同特征，并可能发挥重要作用，在雄性决定的进化轨迹的繁殖方式从单性生殖到有性生殖的多倍体鱼类。
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.