We provide new data on the karyologic patterns of the Andean rodents Aepeomys and Thomasomys, including the 1st karyotypic description of A. lugens and T. vestitus. Two differentiated chromosomal formulae were found for Aepeomys in Venezuela; they are a diploid chromosome number (2n) = 28, fundamental number (FN) = 48 karyotype corresponding to A. lugens and a 2n = 44; FN = 46 karyotype for an unnamed population (Aepeomys sp.). According to the structure of these 2 karyotypes and the distribution of constitutive heterochromatin (scarce and restricted to a few chromosomes in A. lugens versus abundant and scattered among chromosomes in Aepeomys sp.), we suggest that Aepeomys sp. is a more primitive form than A. lugens. T. laniger and T. vestitus showed karyotypes of 2n = 42, FN = 40 and 2n = 44, FN = 42, respectively; the latter has an additional pair of small-sized metacentric chromosomes and an acrocentric X chromosome (metacentric in T. laniger). Our results suggest that Aepeomys and Thomasomys are closely related taxa in terms of their karyologic patterns.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.