Janice Quadros, Alex M V Ferreira, Patrik F Viana, Leandro Marajó, Ezequiel Oliveira, Efrem Ferreira, Eliana Feldberg
{"title":"亚马逊孔雀鲈鱼6种的细胞遗传学比较:同域种间的染色体内变异和遗传渗入。","authors":"Janice Quadros, Alex M V Ferreira, Patrik F Viana, Leandro Marajó, Ezequiel Oliveira, Efrem Ferreira, Eliana Feldberg","doi":"10.3897/CompCytogen.v14i3.55279","DOIUrl":null,"url":null,"abstract":"<p><p>Cytogenetic data for the genus <i>Cichla</i> Bloch et Schneider, 1801 are still very limited, with only four karyotype descriptions to date. The sum of the available cytogenetic information for <i>Cichla</i> species, points to a maintenance of the diploid number of 48 acrocentric chromosomes, considered a typical ancestral feature in cichlids. In the current study, we performed molecular and classical cytogenetic analyses of the karyotype organization of six species of <i>Cichla</i>, the earliest-diverging genus of Neotropical cichlids. We cytogenetically analysed <i>Cichla kelberi</i> Kullander et Ferreira, 2006, <i>Cichla monoculus</i> Agassiz, 1831, <i>Cichla piquiti</i> Kullander et Ferreira, 2006, <i>Cichla temensis</i> Humboldt, 1821, <i>Cichla vazzoleri</i> Kullander et Ferreira, 2006 and <i>Cichla pinima</i> Kullander et Ferreira, 2006, including three individuals that showed mixed morphological characteristics, likely from different species, suggesting they were hybrid individuals. All individuals analysed showed 2n = 48 acrocentric chromosomes, with centromeric heterochromatic blocks on all chromosomes and a terminal heterochromatic region on the <i>q</i> arm of the 2<sup>nd</sup> pair. Mapping 18S rDNA gave hybridization signals, correlated with the nucleolus organizer regions, on the 2<sup>nd</sup> pair for all analyzed individuals. However, we found distinct patterns for 5S rDNA: interstitially at the proximal position on 6<sup>th</sup> pair of four species (<i>C. kelberi</i>, <i>C. pinima</i>, <i>C. piquiti</i> and <i>C. vazzoleri</i>), and on the distal of the 4<sup>th</sup> pair in two (<i>C. monoculus</i> and <i>C. temensis</i>). Accordingly, we present here new data for the genus and discuss the evolutionary trends in the karyotype of this group of fish. 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引用次数: 2
摘要
1801年关于赤藓属Bloch et Schneider的细胞遗传学数据仍然非常有限,迄今为止只有四种核型描述。现有的细胞遗传信息的总和表明,维持了48个顶心染色体的二倍体数目,这被认为是慈鲷的典型祖先特征。在本研究中,我们对新热带慈鲷属中分化最早的六种慈鲷的核型组织进行了分子和经典细胞遗传学分析。我们对kelberi Cichla Kullander et Ferreira, 2006, Cichla monoculus Agassiz, 1831, Cichla piquiti Kullander et Ferreira, 2006, Cichla temensis Humboldt, 1821, Cichla vazzoleri Kullander et Ferreira, 2006和Cichla pinima Kullander et Ferreira, 2006进行了细胞遗传学分析,包括三个表现出混合形态特征的个体,可能来自不同的物种,表明它们是杂交个体。所有个体均有2n = 48条外中心染色体,所有染色体上均有着丝点异色块,第2对染色体的q臂上有一个末端异色区。在所有被分析个体的第2对上,18S rDNA图谱给出了与核仁组织区相关的杂交信号。然而,我们发现了不同的5S rDNA模式:在4个物种(C. kelberi、C. pinima、C. piquiti和C. vazzoleri)的第6对染色体上,间隙位于近端;在2个物种(C. monoculus和C. temensis)的第4对染色体的远端。因此,我们在这里提出了该属的新数据,并讨论了这类鱼类核型的进化趋势。此外,我们主要基于5S rDNA图谱,提供了支持Uatumã River地区存在杂交个体的数据。
Comparative cytogenetic of six species of Amazonian Peacock bass (Cichla, Cichlinae): intrachromosomal variations and genetic introgression among sympatric species.
Cytogenetic data for the genus Cichla Bloch et Schneider, 1801 are still very limited, with only four karyotype descriptions to date. The sum of the available cytogenetic information for Cichla species, points to a maintenance of the diploid number of 48 acrocentric chromosomes, considered a typical ancestral feature in cichlids. In the current study, we performed molecular and classical cytogenetic analyses of the karyotype organization of six species of Cichla, the earliest-diverging genus of Neotropical cichlids. We cytogenetically analysed Cichla kelberi Kullander et Ferreira, 2006, Cichla monoculus Agassiz, 1831, Cichla piquiti Kullander et Ferreira, 2006, Cichla temensis Humboldt, 1821, Cichla vazzoleri Kullander et Ferreira, 2006 and Cichla pinima Kullander et Ferreira, 2006, including three individuals that showed mixed morphological characteristics, likely from different species, suggesting they were hybrid individuals. All individuals analysed showed 2n = 48 acrocentric chromosomes, with centromeric heterochromatic blocks on all chromosomes and a terminal heterochromatic region on the q arm of the 2nd pair. Mapping 18S rDNA gave hybridization signals, correlated with the nucleolus organizer regions, on the 2nd pair for all analyzed individuals. However, we found distinct patterns for 5S rDNA: interstitially at the proximal position on 6th pair of four species (C. kelberi, C. pinima, C. piquiti and C. vazzoleri), and on the distal of the 4th pair in two (C. monoculus and C. temensis). Accordingly, we present here new data for the genus and discuss the evolutionary trends in the karyotype of this group of fish. In addition, we provide data that supports the occurrence of hybrid individuals in the Uatumã River region, mainly based on 5S rDNA mapping.
期刊介绍:
Comparative Cytogenetics is a peer-reviewed, open-access, rapid online journal launched to accelerate research on all aspects of plant and animal cytogenetics, karyosystematics, and molecular systematics.
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