Ctenoluciidae (Characiformes), a family of freshwater fishes, comprises 2 genera, Ctenolucius and Boulengerella, with 7 recognized species. Up to now, only species of the genus Boulengerella have been subjected to cytogenetic studies. Here, we investigated the karyotype and other cytogenetic features of pike characin, Ctenolucius hujeta, using conventional (Giemsa staining, C-banding, Ag-NOR staining) and molecular (rDNA, telomeric sequences, and fiber-FISH mapping) procedures. This species has a diploid chromosome number of 2n = 36, and a karyotype composed of 12m + 20sm + 4a and FN = 68, similar to that found in Boulengerella species. However, differences regarding the number and distribution of several chromosomal markers support a distinct generic status. Colocalization of the 18S and 5S rDNA genes is an exclusive characteristic of the C. hujeta genome, with an interspersed distribution in the chromosomal fiber, an unusual phenomenon among eukaryotes. Additionally, our results support the view that Ctenoluciidae and Lebiasinidae families are closely related.
Cytogenet Genome Res

中文翻译：

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Ctenolucius hujeta Valenciennes, 1850 (Characiformes) 的染色体分析：Ctenoluciidae 染色体进化的新片段

Ctenoluciidae (Characiformes) 是淡水鱼类的一个科，包括 2 个属，Ctenolucius和Boulengerella，有 7 个公认的物种。到目前为止，仅对Boulengerella属的物种进行了细胞遗传学研究。在这里，我们使用常规（吉姆萨染色、C 显带、Ag-NOR 染色）和分子（rDNA、端粒序列和纤维 FISH 映射）程序研究了梭鱼Ctenolucius hujeta的核型和其他细胞遗传学特征。该物种的二倍体染色体数为2n = 36，核型由12m + 20sm + 4a和FN = 68组成，类似于在Boulengerella中发现的物种。然而，关于几个染色体标记的数量和分布的差异支持不同的通用状态。18S 和 5S rDNA 基因的共定位是C. hujeta基因组的独有特征，在染色体纤维中散布分布，这是真核生物中的一种不寻常现象。此外，我们的研究结果支持 Ctenoluciidae 和 Lebiasinidae 科密切相关的观点。
细胞遗传基因组研究