Repetitive sequences form a substantial and still enigmatic part of the mammalian genome. We isolated repetitive DNA blocks of the X chromosomes of three species of the family Bovidae: Kobus defassa (KDEXr sequence), Bos taurus (BTAXr sequence) and Antilope cervicapra (ACEXr sequence). The copy numbers of the isolated sequences were assessed using qPCR, and their chromosomal localisations were analysed using FISH in ten bovid tribes and in outgroup species. Besides their localisation on the X chromosome, their presence was also revealed on the Y chromosome and autosomes in several species. The KDEXr sequence abundant in most Bovidae species also occurs in distant taxa (Perissodactyla and Carnivora) and seems to be evolutionarily older than BTAXr and ACEXr. The ACEXr sequence, visible only in several Antilopini species using FISH, is probably the youngest, and arised in an ancestor common to Bovidae and Cervidae. All three repetitive sequences analysed in this study are interspersed among gene-rich regions on the X chromosomes, apparently preventing the crossing-over in their close vicinity. This study demonstrates that repetitive sequences on the X chromosomes have undergone a fast evolution, and their variation among related species can be beneficial for evolutionary studies.

• Keywords
• Bovidae, FISH, X chromosome, laser microdissection, qPCR, repetitive sequence, sequence analysis,
• MeSH
• Antelopes * genetics   MeSH
• Y Chromosome genetics   MeSH
• DNA MeSH
• Humans MeSH
• Chromosomes, Human, X MeSH
• Repetitive Sequences, Nucleic Acid genetics   MeSH
• Cattle genetics   MeSH
• Deer * genetics   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Cattle genetics   MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• DNA MeSH

Mazama simplicicornis argentina is the name that was given to describe a gray brocket collected by Lönberg in 1919 in the central Chaco region of Argentina. Subsequent authors, based on morphological similarities, considered this name to be a synonym for the species Subulo gouazoubira Fischer, 1814 from Paraguay. In the absence of genetic analyses to compare the Argentinian and Paraguayan gray brockets, we aimed to clarify the taxonomy of M. simplicicornis argentina through an integrative assessment using morphological, cytogenetical, and molecular data from its holotype and a current topotype. Qualitative skull features and cranio-morphometric results of M. simplicicornis argentina showed a great similarity with the S. gouazoubira neotype characters. The diploid chromosome number of M. simplicicornis argentina topotype corresponded with the karyotypical pattern of S. gouazoubira with 2n = 70 and FN = 70, showing a great similarity in all classic and molecular cytogenetic results and revealing the homologies between karyotypes. The phylogenetic analysis of mitochondrial genes used in this study (concatenated partial ND5 and Cytb gene) allocated the M. simplicicornis argentina specimens in the monophyletic clade of S. gouazoubira with a branch value of 100%. These results show that there is no discontinuity between the Argentinian and Paraguayan gray brockets. Therefore, the individuals originally described as M. simplicicornis argentina should be recognized as S. gouazoubira.

• Keywords
• Animal cytogenetic, Cervidae, Gray brocket, Mitochondrial DNA, Morphology,
• Publication type
• Journal Article MeSH

Mazamanemorivaga (Cuvier, 1817) is a gray brocket deer that inhabits the Amazon region. An assessment of previous studies revealed inconsistencies in its current taxonomic classification, suggesting the need for an update in its genus classification. A taxonomic repositioning of this species is proposed through the collection of a specimen from its type locality (French Guiana) with subsequent morphological (coloring pattern, body measurements, and craniometry), cytogenetics (G Band, C Band, conventional Giemsa, Ag-NOR staining, and BAC probe mapping), and molecular phylogenetic analysis (mitochondrial genes Cyt B of 920 bp, COI I of 658 bp, D-loop 610 bp), and comparisons with other specimens of the same taxon, as well as other Neotropical deer species. The morphological and cytogenetic differences between this and other Neotropical Cervidae confirm the taxon as a unique and valid species. The phylogenetic analysis evidenced the basal position of the M.nemorivaga specimens within the Blastocerina clade. This shows early diversification and wide divergence from the other species, suggesting that the taxon should be transferred to a different genus. A taxonomic update of the genus name is proposed through the validation of Passalites Gloger, 1841, with Passalitesnemorivagus (Cuvier, 1817) as the type species. Future research should focus on evaluating the potential existence of other species within the genus Passalites, as suggested in the literature.

• Keywords
• Cervidae, Mazamanemorivaga, brocket deer, new genus, taxonomy,
• Publication type
• Journal Article MeSH

The red brocket deer Mazama americana Erxleben, 1777 is considered a polyphyletic complex of cryptic species with wide chromosomal divergence. Evidence indicates that the observed chromosomal divergences result in reproductive isolation. The description of a neotype for M. americana allowed its genetic characterization and represented a comparative basis to resolve the taxonomic uncertainties of the group. Thus, we designated a neotype for the synonym Mazama rufa Illiger, 1815 and tested its recognition as a distinct species from the M. americana complex with the analysis of morphological, cytogenetic and molecular data. We also evaluated its distribution by sampling fecal DNA in the wild. Morphological data from craniometry and body biometry indicated an overlap of quantitative measurements between M. rufa and the entire M. americana complex. The phylogenetic hypothesis obtained through mtDNA confirmed the reciprocal monophyly relationship between M. americana and M. rufa, and both were identified as distinct molecular operational taxonomic units by the General Mixed Yule Coalescent species delimitation analysis. Finally, classic cytogenetic data and fluorescence in situ hybridization with whole chromosome painting probes showed M. rufa with a karyotype of 2n = 52, FN = 56. Comparative analysis indicate that at least fifteen rearrangements separate M. rufa and M. americana (sensu stricto) karyotypes, which confirmed their substantial chromosomal divergence. This divergence should represent an important reproductive barrier and allow its characterization as a distinct and valid species. Genetic analysis of fecal samples demonstrated a wide distribution of M. rufa in the South American continent through the Atlantic Forest, Cerrado and south region of Amazon. Thus, we conclude for the revalidation of M. rufa as a distinct species under the concept of biological isolation, with its karyotype as the main diagnostic character. The present work serves as a basis for the taxonomic review of the M. americana complex, which should be mainly based on cytogenetic characterization and directed towards a better sampling of the Amazon region, the evaluation of available names in the species synonymy and a multi-locus phylogenetic analysis.

• Keywords
• GMYC, Odocoileini, bayesian phylogenetic inference, cytotaxonomy, molecular cytogenetics, non-invasive sampling, scat detection dog,
• Publication type
• Journal Article MeSH

The family Cervidae groups a range of species with an increasing economic significance. Their karyotypes share 35 evolutionary conserved chromosomal segments with cattle (Bos taurus). Recent publication of the annotated red deer (Cervus elaphus) whole genome assembly (CerEla1.0) has provided a basis for advanced genetic studies. In this study, we compared the red deer CerEla1.0 and bovine ARS-UCD1.2 genome assembly and used fluorescence in situ hybridization with bovine BAC probes to verify the homology between bovine and deer chromosomes, determined the centromere-telomere orientation of the CerEla1.0 C-scaffolds and specified positions of the cervid evolutionary chromosome breakpoints. In addition, we revealed several incongruences between the current deer and bovine genome assemblies that were shown to be caused by errors in the CerEla1.0 assembly. Finally, we verified the centromere-to-centromere orientation of evolutionarily fused chromosomes in seven additional deer species, giving a support to previous studies on their chromosome evolution.

• Keywords
• BAC mapping, FISH, chromosome fission, chromosome fusion, comparative cytogenetics, genome assembly, karyotype,
• Publication type
• Journal Article MeSH

Chromosomal aberrations and their mechanisms have been studied for many years in livestock. In cattle, chromosomal abnormalities are often associated with serious reproduction-related problems, such as infertility of carriers and early mortality of embryos. In the present work, we review the mechanisms and consequences of the most important bovine chromosomal aberrations: Robertsonian translocations and reciprocal translocations. We also discuss the application of bovine cell cultures in genotoxicity studies.

• Keywords
• Robertsonian translocations, aberrations, cattle, chromosomes, genotoxic agents, reciprocal translocations,
• MeSH
• Chromosome Aberrations * MeSH
• Cattle Diseases genetics   MeSH
• Cattle genetics   MeSH
• Translocation, Genetic * MeSH
• Animals MeSH
• Check Tag
• Cattle genetics   MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Centromeric and pericentromeric chromosome regions are occupied by satellite DNA. Satellite DNAs play essential roles in chromosome segregation, and, thanks to their extensive sequence variability, to some extent, they can also be used as phylogenetic markers. In this paper, we isolated and sequenced satellite DNA I-IV in 11 species of Cervidae. The obtained satellite DNA sequences and their chromosomal distribution were compared among the analysed representatives of cervid subfamilies Cervinae and Capreolinae. Only satI and satII sequences are probably present in all analysed species with high abundance. On the other hand, fluorescence in situ hybridisation (FISH) with satIII and satIV probes showed signals only in a part of the analysed species, indicating interspecies copy number variations. Several indices, including FISH patterns, the high guanine and cytosine (GC) content, and the presence of centromere protein B (CENP-B) binding motif, suggest that the satII DNA may represent the most important satellite DNA family that might be involved in the centromeric function in Cervidae. The absence or low intensity of satellite DNA FISH signals on biarmed chromosomes probably reflects the evolutionary reduction of heterochromatin following the formation of chromosome fusions. The phylogenetic trees constructed on the basis of the satellite I-IV DNA relationships generally support the present cervid taxonomy.

• Keywords
• FISH, centromere, cervid phylogeny, satellite DNA, sequencing,
• MeSH
• Centromere genetics   MeSH
• Heterochromatin genetics   MeSH
• In Situ Hybridization, Fluorescence methods   MeSH
• Humans MeSH
• Ruminants genetics   MeSH
• Repetitive Sequences, Nucleic Acid genetics   MeSH
• DNA, Satellite genetics   MeSH
• DNA Copy Number Variations genetics   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Heterochromatin MeSH
• DNA, Satellite MeSH