Distribution of tolypeutes illiger, 1811 (xenarthra: cingulata) with comments on its biogeography and conservation.

This study reviews the data available on the distribution of three-banded armadillos of the genus Tolypeutes, identifying potential geographic barriers and evaluating possible biogeographic processes that may account for the present-day distribution of the species and its conservation status. The database was derived from published records, interviews, and voucher specimens, over a timescale ranging from the fossil record to specimens collected in 2013. A total of 236 localities were recorded, with 68 attributed to Tolypeutes matacus and 168 to Tolypeutes tricinctus. The vegetation within the range of the genus is predominantly a xerophytic mosaic of grassland, savannas, open woodland, and xeric thorn forest. The marine transgressions of the Miocene and the uplifting of the Brazilian Shield may have contributed to the vicariant separation of the ancestral populations of T. matacus, to the west and south, and T. tricinctus, to the north and east. The three-banded armadillo is possibly one of the most threatened of Brazilian mammals, considering the low number of recent records and the fact that it is hunted intensively throughout its range.

Phylogenetic and phylogeographic patterns in sigmodontine rodents of the genus oligoryzomys.

The sigmodontine South American rodent genus Oligoryzomys was first described as a subgenus of the genus Oryzomys to group together species distinguished by morphological measurements. To describe the dispersion patterns of this genus in South America, in this study, a total of 100 sequences were analyzed and compared with sequences of 9 Oligoryzomys species from GenBank. The sequences comprised 90 mitochondrial cytochrome b genes and 10 nuclear interphotoreceptor retinoid-binding protein genes, from 75 individuals of 7 species from 27 localities. Topologies of different phylogenetic trees revealed Oligoryzomys as a monophyletic genus containing 2 main species groups, one designated as the "Amazon-Cerrado" assemblage and the second as the "Pampa-Andean" clade. The north-to-south geographic pattern observed supports the hypothesis that the genus started from the northern Andes, occupied the Amazon and the Cerrado, and later inhabited the more southern regions of South America.

Cytotaxonomy of the subgenus Artibeus (Phyllostomidae, Chiroptera) by characterization of species-specific markers.

The genus Artibeus represents a highly diverse group of bats from the Neotropical region, with four large species occurring in Brazil. In this paper, a comparative cytogenetic study was carried out on the species Artibeus obscurus Schinz, 1821, Artibeus fimbriatus Gray, 1838, Artibeus lituratus Olfers, 1818 and Artibeus planirostris Spix, 1823 that live sympatrically in the northeast of Brazil, through C-banding, silver staining and DNA-specific fluorochromes (CMA3 and DAPI). All the species had karyotypes with 2n=30,XX and 2n=31,XY1Y2, and FN=56. C-banding showed constitutive heterochromatin (CH) blocks in the pericentromeric regions of all the chromosomes and small CH blocks at the terminal region of pairs 5, 6, and 7 for all species. Notably, our C-banding data revealed species-specific autosomic CH blocks for each taxon, as well as different heterochromatic constitution of Y2 chromosomes of Artibeus planirostris. Ag-NORs were observed in the short arms of chromosomes 5, 6 and 7 in all species. The sequential staining AgNO3/CMA3/DA/DAPI indicated a positive association of CH with Ag-NORs and positive CMA3 signals, thus reflecting GC-richness in these regions in Artibeus obscurus and Artibeus fimbriatus. In this work it was possible to identify interespecific divergences in the Brazilian large Artibeus species using C-banding it was possible provided a suitable tool in the cytotaxonomic differentiation of this genus.

Geographic patterns of genetic variation and conservation consequences in three South American rodents.

In this study, the geographic patterns of genetic variation of three rodent species belonging to the tribe Oryzomyini were investigated using the mitochondrial cytochrome b and nuclear IRBP genes in biomes that are undergoing degradation processes to a greater or lesser degree. The samples are from 25 collecting localities distributed throughout the Amazon, Cerrado, Atlantic Forest, and Pampa biomes. The results show that the three species have a population and geographic structure, besides being in demographic equilibrium. The phylogenetic analyses performed on Euryoryzomys russatus and Hylaeamys megacephalus showed these specimens grouped in three distinct clades forming geographic gradients (North-South direction in H. megacephalus). Intraspecific genetic divergence was higher in H. megacephalus (4.53%), followed by E. russatus (1.79%), and lowest in Sooretamys angouya (0.88%). The results obtained indicate that, necessarily, the management strategies to preserve genetic diversity should be different for each species, since each of them presented specific population parameters.

(T2AG3)n telomeric sequence hybridization indicating centric fusion rearrangements in the karyotype of the rodent oryzomys subflavus.

Chromosome preparations of 30 specimens of Oryzomys subflavus trapped in eight Brazilian localities were C-, and G-banded and analyzed by fluorescence in situ hybridization (FISH). Two karyotypes were found, 2n = 50/FN = 64, at three coastal localities of the Atlantic Forest domain, and 2n = 58/FN = 70 at two sites located in the Cerrado biome, Brazil Central. Two fluorescence in situ hybridization (FISH) patterns of the telomeric sequence (T2AG3)n were observed: in both karyotypes the probes hybridized to the telomeres of all chromosomes and also a hybridization signal in the centromeric regions of two autosome pairs was seen in the 2n = 50 karyotype. These results, together with the occurrence of other diploid numbers described in the literature, suggest that 0. subflavus is a complex species, bearing fusion/fission rearrangements proper to the different biomes which it inhabits.