The family Centropomidae includes a number of fish species of high commercial value. One of these species, Centropomus undecimalis, is a target of artisanal, industrial, and sports fisheries and has also considerable potential for captive breeding, which has led to its inclusion in several aquaculture programs. While the biology and ecology of C. undecimalis are relatively well documented, few karyological data are available on this species, and they are still scarce for other centropomids. The few chromosomal data available on this family indicate a conserved karyotype 2n = 48, but it is unclear whether the chromosome microstructure is also conserved. In this study, new cytogenetic data are presented on C. undecimalis from the Amazon coastal zone, including C-banding, Ag-NOR, in situ hybridization with repetitive DNA probes (5S and 18S ribosomal genes), and telomeric (TTAGGG)n sequences. The diploid number of the species was 2n = 48, with heterochromatic blocks in the centromeric and pericentromeric regions, as well as distal signals; the nucleolus organizer regions (NORs) were associated with the heterochromatic region. The 18S and 5S recombinant DNA (rDNA) clusters were located in the distal region of chromosome pairs 1 and 11, respectively. The similarities of the karyotype macrostructure found among the centropomid species reinforce their exceptional chromosomal stability. However, the presence of heterochromatic blocks and location of NORs suggest the occurrence of structural rearrangements, which indicates that evolutionary dynamics at the microstructural level in this group may be relatively complex and should be evaluated carefully in any study that targets the production of hybrids for aquaculture.

中文翻译：

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Undecimalis（Perperformes，Centropomidae）中重复序列的基因组组织：对杂交和水产养殖计划的影响。

Centr科包括许多具有较高商业价值的鱼类。这些物种之一，无刺中枢（Centropomus undecimalis），是手工，工业和体育渔业的目标，而且圈养繁殖的潜力也很大，因此已被纳入若干水产养殖计划。尽管十一角线虫的生物学和生态学都有相对较好的文献记载，但关于该物种的鸟类学数据很少，对于其他cent虫类而言仍然很少。该家族的一些染色体数据表明保守的核型2n = 48，但尚不清楚染色体的微结构是否也保守。在这项研究中，我们提出了来自亚马逊沿岸带的十一线虫的新细胞遗传学数据，包括C带，Ag-NOR，与重复的DNA探针（5S和18S核糖体基因）和端粒（TTAGGG）n序列进行原位杂交。该物种的二倍体数为2n = 48，在着丝粒和着丝粒附近以及远端信号中具有异色块。核仁组织区（NORs）与异色区相关。18S和5S重组DNA（rDNA）簇分别位于染色体对1和11的远端区域。在cent类物种中发现的核型宏观结构的相似性增强了它们出色的染色体稳定性。但是，异色块的存在和NOR的位置表明结构重排的发生，