Chromosome evolution in the erythrinid fish, Erythrinus erythrinus (Teleostei: Characiformes)
Chromosome evolution in the erythrinid fish, Erythrinus erythrinus (Teleostei: Characiformes)
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DOI：
10.1038/sj.hdy.6800511
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发表时间：
2004-08-01
期刊：
影响因子：
3.8
通讯作者：
Fenocchio, AS
中科院分区：
文献类型：
--
作者：
Bertollo, LAC;Oliveira, C;Fenocchio, AS
刺鱼属属于新热带鱼类刺鱼科。本属仅包含两个已描述的种，Erythrinus corrinus在南美洲分布最广。本物种的六个样本从五个不同的巴西地区和一个从阿根廷进行了细胞遗传学研究。根据染色体特征确定了四组。A组包括三个样品，均具有2n = 54条染色体，非常相似的核型结构，并且雄性和雌性之间没有染色体分化。一个样本携带多达四个额外的微染色体，看起来像“双微小染色体”。组B-D包括剩余的三个样品，所有样品都共享X1X1X2X2/X1X2Y性染色体系统。组B显示2n = 54/53的女性和男性，分别，也显示多达3个额外的微染色体。C组和D组分别在雌性和雄性中显示2n = 52/51的染色体，但在中部着丝粒染色体、近端着丝粒染色体和端着丝粒染色体的数目上不同。在这三组（B-D）中，Y是一个中着丝粒染色体，在补体中被明确鉴定为最大的。本研究结果提供了明确的证据表明，当地的E。该物种保留了独特的和固定的染色体特征，表明该物种可能代表了一个物种复合体。
The genus Erythrinus belongs to the family Erythrinidae, a neotropical fish group. This genus contains only two described species, Erythrinus erythrinus being the most widely distributed in South America. Six samples of this species from five distinct Brazilian localities and one from Argentina were studied cytogenetically. Four groups were identified on the basis of their chromosomal features. Group A comprises three samples, all with 2n = 54 chromosomes, a very similar karyotypic structure, and the absence of chromosome differentiation between males and females. One sample bears up to four supernumerary microchromosomes, which look like 'double minute chromosomes' in appearance. Groups B - D comprise the three remaining samples, all sharing an X1X1X2X2/X1X2Y sex chromosome system. Group B shows 2n = 54/53 chromosomes in females and males, respectively, and also shows up to three supernumerary microchromosomes. Groups C and D show 2n = 52/51 chromosomes in females and males, respectively, but differ in the number of metacentric, subtelocentric, and acrocentric chromosomes. In these three groups ( B - D), the Y is a metacentric chromosome clearly identified as the largest in the complement. The present results offer clear evidence that local samples of E. erythrinus retain exclusive and fixed chromosomal features, indicating that this species may represent a species complex.