Universidade Estadual de Londrina, Departamento de Biologia Geral, CCB, 86051770 Londrina, PR, Brazil.
J Fish Biol. 2012 Sep;81(4):1415-21. doi: 10.1111/j.1095-8649.2012.03387.x. Epub 2012 Aug 3.
The first chromosomal data in Hoplosternum littorale from an isolated South American drainage in north-eastern Brazil are presented. All specimens were characterized by a diploid number (2n) of 60 chromosomes divided into three metacentric, one submetacentric and 26 acrocentric pairs; single nucleolar organizer regions (NOR) on the sixth pair; centromeric and interstitial heterochromatin; GC-rich sites on four large acrocentric chromosomes, including the NOR-bearing pair, and 5S ribosomal genes at terminal region on short arms of two acrocentric pairs. These data are invariably similar to previous reports in H. littorale from distant localities throughout South America, which contrasts with the chromosomal diversity of Callichthyidae and reinforces the role of human activities on the dispersal and colonization of this fish.
本文呈现了来自巴西北部东北一个孤立的南美水系的小口拟脂鲤的首个染色体数据。所有标本均具有 60 条染色体的二倍体数（2n），分为 3 对中央着丝粒、1 对亚中央着丝粒和 26 对近端着丝粒；第 6 对有单个核仁组织区（NOR）；着丝粒和间质异染色质；4 条大型近端着丝粒染色体上富含 GC 位点，包括带有 NOR 的对，以及 2 条近端着丝粒染色体短臂末端区域的 5S 核糖体基因。这些数据与来自南美的不同地点的小口拟脂鲤的先前报告始终相似，这与甲鲇科的染色体多样性形成对比，并强调了人类活动在这种鱼类的扩散和定植中的作用。
