Rosa C C, Flores T, Pieczarka J C, Rossi R V, Sampaio M I C, Rissino J D, Amaral P J S, Nagamachi C Y
Laboratório de Citogenética, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém 66.075-900, Brazil.
J Genet. 2012;91(3):265-77. doi: 10.1007/s12041-012-0182-2.
The rodent genus Oecomys (Sigmodontinae) comprises ~16 species that inhabit tropical and subtropical forests in Central America and South America. In this study specimens of Oecomys paricola Thomas, 1904 from Belém and Marajó island, northern Brazil, were investigated using cytogenetic, molecular and morphological analyses. Three karyotypes were found, two from Belém (2n = 68, fundamental number (FN) = 72 and 2n = 70, FN = 76) and a third from Marajó island (2n = 70, FN = 72). No molecular or morphological differences were found between the individuals with differing cytotypes from Belém, but differences were evident between the individuals from Belém and Marajó island. Specimens from Belém city region may represent two cryptic species because two different karyotypes are present in the absence of significant differences in morphology and molecular characteristics. The Marajó island and Belém populations may represent distinct species that have been separated for some time, and are in the process of morphological and molecular differentiation as a consequence of reproductive isolation at the geographic and chromosomal levels. Thus, the results suggest that O. paricola may be a complex of species.
鼠属（Sigmodontinae亚科）包含约16个物种，栖息于中美洲和南美洲的热带及亚热带森林。在本研究中，对采自巴西北部贝伦和马拉若岛的1904年托马斯定名的帕氏鼠（Oecomys paricola）标本进行了细胞遗传学、分子生物学和形态学分析。发现了三种核型，两种来自贝伦（2n = 68，基数（FN）= 72和2n = 70，FN = 76），第三种来自马拉若岛（2n = 70，FN = s72）。来自贝伦的具有不同细胞型的个体之间未发现分子或形态学差异，但贝伦和马拉若岛的个体之间差异明显。贝伦市地区的标本可能代表两个隐存种，因为存在两种不同的核型，而形态学和分子特征却没有显著差异。马拉若岛和贝伦的种群可能代表已经隔离了一段时间的不同物种，并且由于地理和染色体水平上的生殖隔离，正处于形态学和分子分化的过程中。因此，结果表明帕氏鼠可能是一个物种复合体。
