Search Results (70)

Camelids are increasingly recognized as important livestock species. They are valuable sources of meat, fiber, and milk. Despite their growing popularity, many aspects of their reproductive physiology and pathology remain unclear. Their reproductive performance is reported to be low in many countries. Advances in camelid veterinary care have identified several disorders, some of which are species-specific. This article describes an approach to and the diagnosis of infertility and subfertility cases in alpacas, llamas, and camels referred to the authors over the past 35 years. Ultrasonography, endometrial cytology, and biopsy are the primary diagnostic tools for practitioners. However, laparoscopy, hysteroscopy, and cytogenetics are indicated for cases referred to theriogenologists. The incidence of congenital and acquired reproductive disorders is presented. A high incidence of congenital defects of the reproductive tract is found in South American camelids, which raises concerns about animal welfare. Acquired disorders are similar to those described in other species. Endometritis and endometrosis are major disorders contributing to infertility and early pregnancy loss. However, studies on uterine defense mechanisms and the pathogenesis of these disorders are lacking. Hydrobursitis, a common cause of infertility in dromedary camels, warrants further research. The implications of some contagious diseases (tuberculosis, campylobacteriosis, and brucellosis) in female infertility are discussed. These findings emphasize the importance of including camelid medicine in veterinary education to ensure a high standard of care for this species. Full article

In Italy, karyotype analysis is routinely performed on all young males intended for reproduction to screen for chromosome abnormalities. This practice gained prominence following the identification of a complex chromosome abnormality in a well-known bull named Magnifico and its progeny. This procedure significantly enhances the value of the Mediterranean Italian River Buffalo breed, particularly in the context of artificial insemination both within Italy and in other countries importing semen. In the current study, 159 young Mediterranean Italian River Buffalo (MIRB) males intended for reproduction, 30 females with fertility issues, 3 young females and a male co-twin were investigated by analyzing their karyotype using both CBA- and RBA-banding. All males displayed a normal karyotype (2n = 50, XY), although one animal displayed an abnormal X-chromosome with C-band polymorphism, as it is C-band negative when this chromosome normally shows the largest C-band among all chromosomes. This result was also confirmed by the FISH-mapping technique using three bovine BAC-clones containing SAT-I, SAT-III and SAT-IV. Cytogenetic investigation showed that seven females, along with one male co-twin, were affected by freemartinism (XX/XY leukocyte chimerism) and were subsequently removed from the farm. In two of these females, clinical and necroscopic examinations showed severe damage of the internal reproductive organs. Full article

In establishing the safety or tolerability profile of bioactive plant extracts, it is important to perform toxicity studies using appropriate, accessible, and sustainable methods. The Allium cepa model is well known and frequently used for accurate environmental risk assessments, as well as for evaluating the toxic potential of the bioactive compounds of plant extracts. The present review focuses on this in vivo cytogenetic model, highlighting its widespread utilization and advantages as a first assessment in monitoring the genotoxicity and cytotoxicity of herbal extracts, avoiding the use of animals for testing. This plant-based assay allows for the detection of the possible cytotoxic and genotoxic effects induced on onion meristematic cells. The outcomes of the Allium cepa assay are comparable to other tests on various organisms, making it a reliable screening test due to its simplicity in terms of implementation, as well as its high sensitivity and reproducibility. 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 widespread use of silver nanoparticles in many industries is increasing every year. Along with this use, there is growing concern about the potential unintentional exposure of human and animal organisms to these nanomaterials. It has been shown that AgNPs have the ability to penetrate organisms and can have harmful effects on cells and organs in the body. In order to reduce the effects of AgNPs on living organisms, newer solutions are being investigated, such as particle stabilization or other methods of synthesizing these particles. The physical synthesis of AgNPs using high-voltage arc discharge (HVAD) may be one of these alternatives. To determine the effect of silver nanoparticles obtained by this method, cytogenetic analysis was performed on domestic dog somatic cells using a cytokinesis-blocking micronucleus assay. In the experiments performed, peripheral blood cells of the domestic dog were exposed in vitro for 3 and 24 h to three tested colloidal silver compounds (unstable AgNP-HVAD, sodium citrate-stabilized silver nanoparticles—AgNP+C, and silver nitrate). The toxicity of these compounds was evaluated at concentrations of 5, 10, and 20 µg/L, and the presence of the following cellular abnormalities was analyzed: micronuclei, nuclear buds, nucleoplasmic bridges, or multinucleated cells. The study showed a significant increase in the number of micronuclei compared to the control sample, as well as the presence of nuclear buds and nucleoplasmic bridges in somatic cells of the domestic dog, confirming the genotoxic nature of the particles. However, there was no cytotoxic effect due to the lower number of multinucleated cells and the absence of apoptotic or necrotic cells in the samples analyzed. Further studies are needed to better understand the mechanisms of toxicity of AgNPs produced by the HVAD method and the extent of their effects on mammalian somatic cells. Full article

Background: The Neuro-2a cell line, derived from a murine neuroblastoma (NB), was established as early as 1969 and originates from a transplantable tumor that arose spontaneously in an A/Jax male mouse in 1940. Since then, it has been applied in over 10,000 studies and is used by the World Organization for Animal Health for the routine diagnosis of rabies. Surprisingly, however, Neuro-2a has never been genetically characterized in detail; this study fills that gap. Methods: The Neuro-2a cell line and two of its derivatives, Neuro-2a TR-alpha and Neuro-2a TR-beta, were analyzed for their chromosomal constitution using molecular cytogenetic approaches. Array comparative genomic hybridization was performed to characterize copy number alterations. Results: Neuro-2A has a hyper-tetraploid karyotype with 70 to 97 chromosomes per cell, and the karyotypes of its two examined derivatives were quite similar. Neither of them had a Y-chromosome. The complex karyotype of Neuro-2a includes mitotically stable dicentres, neocentrics, and complex rearrangements resembling chromothripsis events. Although no amplification of euchromatin or oncogenes was detected, there are five derivative chromosomes with the amplification of centromere-near heterochromatic material and 1–5 additional derivatives consisting only of such material. Conclusions: Since satellite DNA amplification has recently been found in advanced human tumors, this finding may be the corresponding equivalent in mice. An in silico translation of the obtained results into the human genome indicated that Neuro-2A is suitable as a model for advanced human NB. Full article

In this review, we toxicologically assessed the naturally occurring toxin domoic acid. We used the One Health approach because the impact of domoic acid is potentiated by climate change and water pollution on one side, and reflected in animal health, food security, human diet, and human health on the other. In a changing environment, algal blooms are more frequent. For domoic acid production, the growth of Pseudo-nitzschia diatoms is of particular interest. They produce this toxin, whose capability of accumulation and biomagnification through the food web impacts other organisms in the ecosystem. Domoic acid targets nervous system receptors inducing amnestic shellfish poisoning, among other less severe health-related problems. However, the impact of domoic acid on non-target cells is rather unknown, so we reviewed the currently available literature on cytogenetic effects on human and animal cells. The results of different studies indicate that domoic acid has the potential to induce early molecular events, such as oxidative imbalance and DNA damage, thus posing an additional threat which needs to be thoroughly addressed and monitored in the future. Full article

Background/Objectives: Accipitridae mitogenomes exhibit unique structural variations, including duplicated control regions (CRs) that undergo gradual degeneration into pseudo-CRs, revealing a complex evolutionary landscape. However, annotation of this characteristic in a subset of accipitrid genomes is lacking. Due to the taxonomic diversity of Accipitridae and the presence of understudied species, comprehensive mitogenomic studies are essential. This study sought to expand and investigate the evolutionary characteristics of Accipitridae mitogenomes. Methods: A comparative analysis was conducted using the newly acquired complete mitogenomes of Haliastur indus and Accipiter badius poliopsis along with 22 available accipitrid mitogenomes. Codon usage, selective pressure, phylogenetic relationships, and structural variations were comparatively analyzed. Results: Accipitrid mitogenomes showed a strong AT bias with adenine preference. Most protein-coding genes (PCGs) were under purifying selection except for ND3, which underwent positive selection. The ATP8 gene exhibited relaxed purifying selection on codon usage patterns and showed high genetic variation. Selection for ATP8 and ND3 genes was specific to certain clades of accipitrids. Gene order re-examination revealed both non-degenerate CRs and highly degenerate CR2 fragments in the Accipitridae family. Non-degenerate CRs were found in early diverging species, such as Elanus caeruleus and Pernis ptilorhynchus orientalis, while more recent lineages had highly degenerate CR2 fragments with missing conserved element. Repeat motifs and sequence variations were observed in the functional CR. Conclusions: These findings suggest that ATP8 and ND3 genes reflect metabolic adaptations, while CRs indicate potential diversification of these accipitrid species. This study provides valuable insights into mitochondrial genome evolution within the Accipitridae family. Full article

Reactive oxygen species (ROS) are intermediates in oxidation–reduction reactions with the capacity to modify biomolecules and temporarily or permanently alter cell behaviour through signalling pathways under physiological and pathophysiological conditions where there is an imbalance between oxidative factors and the antioxidant response of the organism, a phenomenon known as oxidative stress. Evidence suggests that the differential modulation of ROS-mediated oxidative stress occurs in the pathogenesis and progression of melanoma, and that this imbalance in redox homeostasis appears to be functionally linked to microRNA (miRNA o miRs)-mediated non-mutational epigenetic reprogramming involving genes and transcription factors. The relationship between ROS-mediated stress control, tumour microenvironment, and miRNA expression in melanoma is not fully understood. The aim of this review is to analyse the involvement of miRNAs in the modulation of the signalling pathways involved in ROS-mediated oxidative stress in melanoma. It is hoped that these considerations will contribute to the understanding of the mechanisms associated with a potential epigenetic network regulation, where the modulation of oxidative stress is consolidated as a common factor in melanoma, and therefore, a potential footprint poorly documented. Full article

Genome instability is a characteristic trait of tumours and includes changes in DNA and in chromosomes. The aim of the study was to identify chromosome damage using the sister chromatid exchange assay and DNA fragmentation by the comet assay in dogs with cancer, as well as to determine the suitability of these techniques for the assessment of chromatin stability in healthy and sick dogs. The assays identified genomic instabilities in dogs with cancer (squamous cell carcinoma) and in healthy dogs. The genetic assays are very sensitive and can be used as biomarkers of normal DNA replication and repair potential and the maintenance of control over the entire cell cycle. The use of the cytogenetic tests will enable the more precise assessment of genome stability and integrity in animals and make it possible to determine the number of chromosomal instabilities generated in a given individual, which can be indicative of its health status. The identification of instabilities can be used in routine diagnostic examination in dogs with cancer for more accurate diagnosis and prognosis. Full article

Cancer is a complex pathological condition associated with substantial rates of mortality and morbidity in both humans and animals. Mammary gland tumors in intact female dogs are the most prevalent neoplasms. Surgical intervention remains the primary treatment choice. Alternative therapeutic options have emerged, with histopathological examination being fundamental to confirm the diagnosis and to decide the best therapy. This research focused on the clinicopathological, immunohistochemical, and cytogenetic aspects of canine mammary tumors (CMTs). Most of the animals were mixed-breed, with the majority being older than seven years, and only 16.7% had been spayed before surgery. Caudal abdominal and inguinal mammary glands were the most affected, with regional mastectomy being the predominant treatment (75.0%). Of all the tumors, 29.1% were benign, while 70.9% were malignant. Complex adenoma was the most common benign tumor, whereas tubulopapillary carcinoma was the most common malignant type. Grade III tumors (17.6%) were the least encountered, while grades I and II exhibited a similar prevalence (41.2%). All the carcinomas were classified as luminal, and cytogenetics analysis demonstrated a high chromosomal instability with significant aneuploidy observed in all cases and polyploidy detected in 62.5%. This study holds significance as canine and human breast cancers share similar characteristics, suggesting that dogs could be a valuable model for human breast cancer research. Further studies with larger sample sizes are needed to enhance our understanding of CMTs. 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

An important factor for dairy cattle farmers is the profitability of cattle rearing, which is influenced by the animals’ health and reproductive parameters, as well as their genomic stability and integrity. Bovine viral diarrhea (BVD) negatively affects the health of dairy cattle and causes reproductive problems. The aim of the study was to identify genomic instability in cows with reproductive disorders following infection with the BVD virus. The material for analysis was peripheral blood from Holstein-Friesian cows with reproductive problems, which had tested positive for BVD, and from healthy cows with no reproductive problems, which had tested negative for BVD. Three cytogenetic tests were used: the sister chromatid exchange assay, fragile sites assay, and comet assay. Statistically significant differences were noted between the groups and between the individual cows in the average frequency of damage. The assays were good biomarkers of genomic stability and enabled the identification of individuals with an increased frequency of damage to genetic material that posed a negative impact on their health. The assays can be used to prevent disease during its course and evaluate the genetic resistance of animals. This is especially important for the breeder, both for economic and breeding reasons. Of the three assays, the comet assay proved to be the most sensitive for identifying DNA damage in the animals. Full article

Hybrids between the critically endangered Siamese crocodile (Crocodylus siamensis) and least-concern saltwater crocodile (C. porosus) in captive populations represent a serious challenge for conservation and reintroduction programs due to the impact of anthropogenic activities. A previous study used microsatellite and mitochondrial DNA data to establish the criteria for identifying species and their hybrids; however, the results may have been influenced by biased allelic frequencies and genetic drift within the examined population. To overcome these limitations and identify the true signals of selection, alternative DNA markers and a diverse set of populations should be employed. Therefore, this study used DArT sequencing to identify genome-wide single nucleotide polymorphisms (SNPs) in both species and confirm the genetic scenario of the parental species and their hybrids. A population of saltwater crocodiles from Australia was used to compare the distribution of species-diagnostic SNPs. Different analytical approaches were compared to diagnose the level of hybridization when an admixture was present, wherein three individuals had potential backcrossing. Approximately 17.00–26.00% of loci were conserved between the Siamese and saltwater crocodile genomes. Species-diagnostic SNP loci for Siamese and saltwater crocodiles were identified as 8051 loci and 1288 loci, respectively. To validate the species-diagnostic SNP loci, a PCR-based approach was used by selecting 20 SNP loci for PCR primer design, among which 3 loci were successfully able to differentiate the actual species and different hybridization levels. Mitochondrial and nuclear genetic information, including microsatellite genotyping and species-diagnostic DNA markers, were combined as a novel method that can compensate for the limitations of each method. This method enables conservation prioritization before release into the wild, thereby ensuring sustainable genetic integrity for long-term species survival through reintroduction and management programs. Full article