Abstract We present new karyotype records for six Proechimys species from the Brazilian Amazon. P. echinothrix from the region of Purus River had 2n = 32 chromosomes and a FN = 58, while P. cuvieri from the region of the Japurá River presented 2n = 28 and FN = 46. All individuals presented hybridization with an 18S rDNA probe in a single chromosome pair, with the exception of P. cuvieri from the Japurá region, which presented a third signal in one of the homologs of pair 1. No ITS were found in any of the individuals. Our data supports the hypothesis that the P. cuvieri population from the Japurá Basin and P. echinothrix from the lower Purus are new taxonomic entities. Our data expand the geographic distribution of the cytotype (2n = 40, FN = 54) described for P. gardneri from the Madeira River, and the cytotype (2n = 46, FN = 50), described for P. guyannensis, as well as the recently-described cytotype of P. goeldii (2n = 16, FN = 14). No clear pattern of chromosomal evolution has yet been defined in Proechimys, despite the considerable karyotypic diversity of the genus.

中文翻译：

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来自巴西亚马逊河的 Proechimys 属（啮齿目：Echimyidae）的新核型记录

摘要 我们提供了来自巴西亚马逊的六个 Proechimys 物种的新核型记录。普鲁斯河地区的棘鼱有 2n = 32 条染色体和 FN = 58，而来自 Japurá 河地区的 P. cuvieri 有 2n = 28 和 FN = 46。所有个体都与 18S rDNA 探针杂交单个染色体对，除了来自 Japurá 地区的 P. cuvieri，它在一对 1 的一个同源物中呈现出第三个信号。在任何个体中都没有发现 ITS。我们的数据支持以下假设：来自 Japurá 盆地的 P. cuvieri 种群和来自较低 Purus 的 P. echinothrix 是新的分类实体。我们的数据扩展了对来自马德拉河的 P. gardneri 描述的细胞型（2n = 40，FN = 54）的地理分布，以及对 P. gardneri 描述的细胞型（2n = 46，FN = 50）的地理分布。Guyannensis，以及最近描述的 P. goeldii 细胞型（2n = 16，FN = 14）。尽管该属具有相当多的核型多样性，但尚未在 Proechimys 中定义明确的染色体进化模式。