Conde-Saldaña Cristhian Camilo, Cunha Marina Souza, Albornoz-Garzón Juan Gabriel, Barreto Cynthia Aparecida Valiati, Ibagón Nicole, Villa-Navarro Francisco Antonio, Dergam Jorge Abdala
1 Departamento de Morfologia, Instituto de Biociências, UNESP-Universidade Estadual Paulista "Julio de Mesquita Filho," Botucatu, Brazil.
2 Departamento de Biologia Animal and Universidade Federal de Viçosa, Viçosa, Brazil.
Zebrafish. 2019 Feb;16(1):106-114. doi: 10.1089/zeb.2018.1659. Epub 2018 Dec 4.
The monotypic Astroblepidae fish family includes 81 species distributed along Central and Northern Andes in South America and Panamá in Central America; most aspects regarding its biology, taxonomy, and chromosomal features remain largely unknown. This study reports the karyotype of two sympatric Astroblepus species from the Colombian Andes, aiming to provide novel information on karyotype organization and reveal possible chromosomal rearrangements occurred on these species, through mapping of different repetitive DNA classes, including microsatellites and ribosomal DNA multigene families. The results showed differences in the chromosome number and karyotypic formula: Astroblepus grixalvii had 2n = 52 (28m+8sm +12st +4a) with the metacentric pair number 1 as the largest chromosome pair, whereas Astroblepus homodon had 2n = 54 (30m+8sm +8st +8a) and less evident chromosome size differences. Microsatellite probes marked the tips of all chromosomes in both species except the short arms of acrocentric pair numbers 24 and 25 in A. homodon. Each ribosomal probe marked different chromosome pairs in both species. Microsatellite patterns suggest that the 2n increase probably involved a centric fission event that occurred during the evolutionary history of these species. This is the first karyotype description of an Astroblepus species and it contributes to the theoretical framework about the karyoevolutionary trends within Loricarioidei.
单型的星鼻鲇科鱼类包括81个物种，分布于南美洲安第斯山脉中部和北部以及中美洲的巴拿马；其生物学、分类学和染色体特征的大多数方面在很大程度上仍不为人知。本研究报告了来自哥伦比亚安第斯山脉的两种同域分布的星鼻鲇属物种的核型，旨在通过绘制包括微卫星和核糖体DNA多基因家族在内的不同重复DNA类别的图谱，提供有关核型组织的新信息，并揭示这些物种中可能发生的染色体重排。结果显示染色体数目和核型公式存在差异：格氏星鼻鲇2n = 52(28m + 8sm + 12st + 4a)，其中1号中着丝粒对为最大的染色体对，而霍氏星鼻鲇2n = 54(30m + 8sm + 8st + 8a)，染色体大小差异不太明显。微卫星探针标记了两个物种所有染色体的末端，但霍氏星鼻鲇的24号和25号近端着丝粒对的短臂除外。每个核糖体探针在两个物种中标记不同的染色体对。微卫星模式表明，2n的增加可能涉及这些物种进化历史中发生的一次着丝粒裂变事件。这是首次对星鼻鲇属物种的核型描述，它为关于骨甲鲶科核型进化趋势的理论框架做出了贡献。
