B Chromosome Diversity and Repetitive Sequence Distribution in an Isolated Population of Akodon montensis (Rodentia, Sigmodontinae).

B chromosomes are supernumerary chromosomes found in the karyotypes of approximately 15% of all eukaryotic species. They present parasitic behavior and do not follow the standard Mendelian pattern of inheritance, resulting in an imbalance in gametogenesis. The evolutionary dynamics of B chromosomes is still unknown for many species, but studies indicate that the accumulation of repetitive sequences plays an important role in the differentiation of these elements.

A new species of swamp rat of the genus Scapteromys waterhouse, 1837 (Rodentia: Sigmodontinae) endemic to Araucaria angustifolia forest in Southern Brazil.

A new species of swamp rat of the genus Scapteromys from the Meridional Plateau of Southern Brazil is described. Morphological, molecular, and karyological analysis support the recognition of the new species, distinct from S. aquaticus and S.

Description of the karyotype of Rhagomys rufescens Thomas, 1886 (Rodentia, Sigmodontinae) from Southern Brazil Atlantic forest.

Rhagomys rufescens (Rodentia: Sigmodontinae) is an endemic species of the Atlantic forest from Southern and Southeastern Brazil. Some authors consider Rhagomys as part of the tribe Thomasomyini; but its phylogenetic relationships remain unclear. Chromosomal studies on eight specimens of Rhagomys rufescens revealed a diploid number of 2n = 36 and a number of autosome arms FN = 50.

Evaluation of genetic variability in the collared peccary Pecari tajacu and the white-lipped peccary Tayassu pecari by microsatellite markers.

In this study, the microsatellite technique was used to evaluate the genetic variability in populations of collared and white-lipped peccaries kept in captivity. Six primers developed for domestic pigs were used and amplified in both species. They revealed the presence of five polymorphic loci and one monomorphic locus.

Chromosomal phylogeny of four Akodontini species (Rodentia, Cricetidae) from southern Brazil established by Zoo-FISH using Mus musculus (Muridae) painting probes.

We established chromosome homology maps between Mus musculus (MMU) and five species of the Akodontini tribe, Akodon cursor (2n = 14, 15 and 16), A. montensis (2n = 24), A. paranaensis (2n = 44), A.

Chromosome reshuffling in birds of prey: the karyotype of the world's largest eagle (Harpy eagle, Harpia harpyja) compared to that of the chicken (Gallus gallus).

Like various other diurnal birds of prey, the world's largest eagle, the Harpy (Harpia harpyja), presents an atypical bird karyotype with 2n=58 chromosomes. There is little knowledge about the dramatic changes in the genomic reorganization of these species compared to other birds. Since recently, the chicken provides a "default map" for various birds including the first genomic DNA sequence of a bird species.

The phylogeny of howler monkeys (Alouatta, Platyrrhini): reconstruction by multicolor cross-species chromosome painting.

We performed multidirectional chromosome painting in a comparative cytogenetic study of the three howler monkey species Alouatta fusca, A. caraya and A. seniculus macconnelli (Atelinae, Platyrrhini) in order to reconstruct phylogenetic relationships within this genus.