Heterochromatic variation in <i>Cebus apella </i>(Cebidae, Platyrrhini) of different geographic regions

Abstract

Different kinds of constitutive heterochromatin variation were observed in 72 specimens of Cebus apella, belonging to five distinct subspecies, captured in four geographic regions of South America. One particular chromosome type, affecting pair 19, was found to be exclusive of one subspecies (Cebus apella paraguayanus) and to have a distribution significantly different from that expected at equilibrium. Conversely, some other chromosome polymorphisms were more widespread, with distributions compatible with equilibrium. Other variant types, probably resulting from paracentric inversions involving both heterochromatin and euchromatin, were rarer and restricted to single specimens. Finally, a distinctive chromosome type 11 was found to be exclusive of one subspecies (Cebus apella xanthosternos), where it appeared as a fixed trait.

The Karyotype and C-Banding of Cebus nigrivittatus from the Coastal Cordillera, Venezuela

“…The Y chromosome is also different. For C. nigrivittatus it is a small acrocentric, and for the other 3 species we find a small submetacentric [4,5,8]. Some authors point out that pericentric inversions have played an important role in the qualitative relationships among the genus.…”

“…Some authors [3] report great similarities in karyology among individuals from different geographical regions. However, there are notable distinguishing features in karyology among samples from different regions, enough for several authors to propose their separation into subspecies, due to karyotype differentiation and geographical isolation [4,5]. Due to the lack of information on C. nigrivittatus, we have tried to take a first step towards its karyosystematics by characterizing its most abundant subspecies, C. nigrivittatus brunneus.…”

Cytogenetic Study in a Specimen of Cebus apella with an Atypical Phenotype

“…Utilizing the CBG-banding technique, it was possible to observe heterochromatic homeomorphic blocks in chromosome pairs 4, 11, 12, 13 and 19, as already observed [10] in the various subspecies of C. apella. Chromosome pair 11 showed a marked dif ference in the quantity of constitutive heterochromatin between the two homologues ( fig.…”

“…Such variations were apparently not related to any phenotypic characteristic or geographical distribution. The heterochromatic block of chromosome 11 is located in the distal region of the long arm in most subspecies of C. apella [8][9][10], but it is intercalar in C. a. xanthosternos [11] and absent from C. a. vellerosus [51- The present paper describes the chromosomes of one specimen of C. apella in an attempt to establish its origin, given that it presents both phenotypical and cytogenetic characteristics distinct from the patterns found in previously described subspecies.…”

The primates of the Neotropics: genomes and chromosomes

“…C. apella populations or subspecies from different geographic regions showed chromosome polymorphisms due to variations in constitutive heterochromatin (Matayoshi et al, 1987;Martinez et al, 2002) while C. apella xanthosternos (2n = 54) showed a distinctive chromosome pair in respect to other C. apella (Seuá nez et al, 1986). The conspicuous amount of constitutive heterochromatin of Cebus apella contained two different types of highly repetitive sequences, named CapA and CapB (Fanning et al, 1993).…”