Search Results (5)

Chromosomal instability plays a significant role in karyotype evolution and speciation in mammalian groups with notable intraspecific chromosomal variation. The Cervidae family, known for its rapid karyotypic evolution due to chromosomal fragility, shows substantial chromosomal diversity, making it a focal point for studies on chromosomal evolution, particularly with respect to conservation and taxonomic classification. The Amazon gray brocket deer (Passalites nemorivagus) exhibits pronounced chromosomal polymorphism, including two distinct sex chromosome systems: the ancestral XX/XY system and a new system due to an X–autosome fusion (neo-X), where males present XY1Y2. This variation is intriguing, especially given that the effects on hybrids have not been previously reported. This study uses bovine whole-chromosome painting (WCP) and BAC probes to document karyotypic variation in P. nemorivagus. A male with the XY system and a heterozygous autosomal Robertsonian fusion was paired with a female with neo-X chromosomes, and the resulting female offspring displayed an X–autosome fusion in heterozygosity. The females in this study, hybrids for the sex system, exhibited estrus, copulated, and both gave birth to offspring. This characterization is the first step in investigating the effects of sex chromosome system variation on hybrid viability and fertility, and provides insights into the reproductive biology of Neotropical deer. Full article

Tick-borne piroplasmids are apicomplexan protozoa that infect a wide range of vertebrate hosts, with significant implications for animal and human health. This study investigated the occurrence and genetic diversity of piroplasmids in wild mammals, unconventional pets, and associated ticks in Goiás state, midwestern Brazil. Between April 2023 and January 2024, 105 blood samples, 22 tissue samples, and 300 ticks were collected from 21 mammalian species housed in wildlife screening centers, zoos, and veterinary clinics. Molecular screening targeting the 18S rRNA gene of piroplasmids detected a 25.7% (27/105) overall positivity, with gray brockets (Subulo gouazoubira) and South American tapirs (Tapirus terrestris) showing the highest infection rates. Three tick samples tested positive, including two Amblyomma sculptum nymphs and a male of Amblyomma dubitatum collected from a tapir and capybara (Hydrochoerus hydrochaeris). Cytauxzoon brasiliensis was reported, for the first time, in cougars (Puma concolor) from Goiás state, midwestern Brazil, indicating the role of this feline as a host of this parasite. Babesia goianiaensis was confirmed in a capybara, and Theileria terrestris in tapirs. Phylogenetic analyses clustered gray brockets-associated Theileria sequences with Theileria sp. previously detected in Neotropical deer from Brazil and Theileria cervi. While the phylogenetic analysis of amino acid sequences of the cytochrome c oxidase subunit III separated Theileria genotypes detected in S. gouazoubira from T. cervi, hsp70-based phylogenetic inferences clustered the genotypes detected in Tapirus terrestris with Theileria terrestris, suggesting host-specific evolutionary lineages. These findings contribute to the understanding of Piroplasmida diversity and circulation in South American wild mammals, emphasizing the need for enhanced molecular surveillance to elucidate transmission dynamics, assess potential health risks, and contribute to the establishment of wildlife conservation and One Health strategies. Full article

Considering the taxonomic uncertainties of Neotropical deer species, as well as the threat status of many of them, new studies and strategies for their maintenance are urgently needed. Obtaining live cells is of great importance for the conservation of wild species in order to allow cytogenetic and molecular studies to be carried out and for the construction of genomic resource banks. In order to increase the genetic diversity stored in these banks, the possibility of collecting skin fragments from dead animals (e.g., run over, hunted, deaths related to disease or natural causes) becomes a valuable source and a last alternative for obtaining material from these individuals. However, the interval between the death of the animal and the collection of tissue can directly interfere with the quality of the sample obtained and it is therefore essential to identify the maximum time during which viable cells are still found. Thus, this study sought to establish a protocol for the collection, storage, cryopreservation, and cultivation of skin obtained postmortem from individuals of the species Subulo gouazoubira (gray brocket deer) and Mazama rufa (red brocket deer). The collection of tissue fragments at different postmortem intervals (0 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, and 11 h) was evaluated. The tissues were analyzed for fibroblast cell viability immediately after collection. Their ability to undergo cryopreservation was evaluated based on techniques that can be directly applied to samples obtained in the field and their subsequent thawing and success of cell cultures was performed in the laboratory. Regarding the genetic integrity of the cells, the number of metaphases was observed by the mitotic index. The cell viability presented by the samples always remained above 60%. It was possible to establish cell cultures even with the tissues obtained 11 h after the death of the individuals; however, they required twice as many days to reach bottle confluence compared to the cultures performed with the tissues obtained 0 h after the death of the individuals. The results suggest that the best rates of cell viability, time to reach confluence, and number of metaphases per cell (mitotic index) are found in skin fragments collected up to 5 h after the death of individuals when their carcasses are kept at room temperature. Full article

The Neotropical deer genus Mazama is characterized by homoplastic morphological characters, a high karyotypic diversity, and a polyphyletic condition. The species of the genus have been recovered into two multigeneric lineages, the subtribes Odocoileina and Blastocerina, of the tribe Odocoileini (New World deer) in the family Cervidae. Within the Blastocerina, gray brockets include two non-sister species, Subulo gouazoubira, occurring south of the Amazon region, and Passalites nemorivagus, occurring in the Guianas and in the Amazon region. We clarify the taxonomic status and phylogenetic position of Mazama americana citus Osgood, 1912 (referred to as either S. gouazoubira or P. nemorivagus by other authors). We collected a topotype of M. a. citus from the eastern shore of Lake Maracaibo, Venezuela, characterize it morphologically and cytogenetically (conventional banding and fluorescence in situ hybridization), and carry out a phylogenetic analysis of its whole mitogenome and Cytb alongside two additional specimens of M. a. citus from northwestern Venezuela. Our analyses reveal the topotype to be a large gray brocket with a cinnamon band above the eyes and 2n = 61 and FN = 70 karyotype. Using cattle whole chromosome painting and bacterial artificial chromosome X probes, we determined its karyotype to differ in at least 10 rearrangements from that of S. gouazoubira. Bayesian inference recovers M. a. citus within the Blastocerina subtribe, separated phylogenetically from other gray brockets (100% branch value), revealing the Osgood’s gray brocket to be a valid species that should be assigned to a new genus. We propose the generic name Bisbalus, with Bisbalus citus (Osgood, 1912) as the type species. Full article

Human ehrlichiosis are scantily documented in Uruguay. The aim of this study was to investigate the presence of Ehrlichia spp. in Haemaphysalis juxtakochi and in a gray brocket deer (Mazama gouazoubira) from Uruguay. The presence of Ehrlichia DNA was investigated in free-living H. juxtakochi in five localities of southeast and northeast Uruguay, as well as blood, spleen, and ticks retrieved from a M. gouazoubira. Ehrlichia spp. DNA was detected in six out of 99 tick pools from vegetation, in the spleen of M. gouazoubira, and in one out of five pools of ticks feeding on this cervid. Bayesian inference analyses for three loci (16S rRNA, dsb, and groEL) revealed the presence of a new rickettsial organism, named herein as “Candidatus Ehrlichia pampeana”. This new detected Ehrlichia is phylogenetically related to those found in ticks from Asia, as well as Ehrlichia ewingii from USA and Cameroon. Although the potential pathogenicity of “Ca. E. pampeana” for humans is currently unknown, some eco-epidemiological factors may be relevant to its possible pathogenic role, namely: (i) the phylogenetic closeness with the zoonotic agent E. ewingii, (ii) the evidence of H. juxtakochi parasitizing humans, and (iii) the importance of cervids as reservoirs for zoonotic Ehrlichia spp. The molecular detection of “Ca. E. pampeana” represents the third Ehrlichia genotype described in Uruguay. Full article