Search Results (99)

Lumpy skin disease (LSD) is a transboundary viral disease of cattle, including Asian water buffalo and yaks, and certain wild ruminants (e.g., African buffalo, giraffe, wildebeest, eland, and Arabian oryx). It is caused by lumpy skin disease virus (LSDV), a member of the genus Capripoxvirus (family Poxviridae) together with goatpox virus (GTPV) and sheeppox virus (SPPV). High nucleotide identity and serological cross-reactivity among these viruses hinder differential diagnosis. The aim of this study was to develop a Duplex TaqMan-MGB qPCR Assay for Differential Detection of Chinese Epidemic Lumpy Skin Disease Virus Strains and Goatpox Virus. We developed a duplex TaqMan-MGB real-time PCR (qPCR) assay targeting the LSDV GPCR and GTPV RPO30 loci. Virus-specific primers and MGB probes were designed, and the reaction was optimized for single-tube, two-target detection. The assay showed no cross-amplification, limits of detection of 1 × 10¹ copies/μL (LSDV) and 1 × 10¹ copies/μL (GTPV), and coefficients of variation < 1%. The assay was applied to 175 yak-derived field specimens from Qinghai–Tibet Plateau, of which 16 and 36 were positive for LSDV and GTPV, respectively. LSDV- and GTPV-positive samples showed specific amplification in the FAM and VIC channels, respectively. The duplex format enables concurrent detection and unambiguous differentiation of LSDV and GTPV and is compatible with high-throughput screening. This sensitive, specific, and reproducible assay supports surveillance and control of LSD in endemic and at-risk regions. Full article

Background/Objectives: The domestic yak (Bos grunniens) is a livestock species of major relevance in high-altitude environments and an important model for studying adaptation and reproductive isolation within Bovini. Despite its close phylogenetic relationship with cattle (Bos taurus), yak × cattle hybrids show a marked sex-biased fertility pattern, with fertile females and generally sterile F1 males, suggesting that subtle chromosomal or genomic differences may underlie post-zygotic reproductive barriers. In this study, we performed a cytogenetic characterization of eight adult yak bulls imported and reared in Central Italy using conventional and molecular cytogenetic approaches. Results: GTG-, RBG-, RBA- and CBA-banding confirmed the yak diploid number as 2n = 60 and the fundamental number as NF = 62, with banding patterns highly comparable to the standardized cattle karyotype. CBA-banding showed an X chromosome lacking evident constitutive heterochromatin and a Y chromosome with distal C-positive blocks. Chromosome instability was low, with 3.75% abnormal metaphases, mainly represented by chromatid and iso-chromatid breaks, while the mean sister chromatid exchange (SCE) rate was 5.19 ± 2.14 per cell. Sequential Ag-NOR/RBA staining localized nucleolar organizer regions (NORs) at the telomeres of autosomes 2, 3, 4, 11 and 25, as in cattle. Zoo-FISH using bovine chromosome paints for X, Y, 5 and 15 showed complete hybridization to the corresponding yak chromosomes, and BAC-FISH mapped the Y-linked ZFY and SRY genes to positions homologous to those reported in cattle. A comparative bioinformatics analysis of available yak genome assemblies confirmed the overall genome-wide correspondence with cattle, while revealing chromosome orientation issues and small local inconsistencies that may be relevant for comparative mapping and probe design. Conclusions: Overall, at the resolution tested, these findings support broad macrostructural conservation of yak and cattle karyotypes and provide cytogenetic reference data for yak populations reared outside of their traditional range. The persistence of F1 male sterility despite this large-scale chromosomal conservation suggests that fine-scale sex chromosome differences, particularly involving pseudoautosomal regions, recombination boundaries, or heterochromatin organization, may deserve targeted investigation. Full article

Clostridium perfringens type A causes neonatal clostridial enteritis, hemorrhagic enteritis, and sudden death syndrome in cattle. This study examined a fatal outbreak at a fattening farm housing 58 adult yaks in Southwest China, with an incidence of 22.41% (13/58) and a 100% case fatality rate. Histopathology of deceased yaks showed widespread multi-organ hemorrhage and severe hemorrhagic enteritis. A specific PCR assay amplified the alpha-toxin gene of Clostridium perfringens, while no other pathogens were detected. Clostridium perfringens was isolated from small intestinal contents using TSC agar, designated strain CQ1, and identified as type A through toxinotyping. Whole-genome sequencing revealed that strain CQ1 carries the core alpha-toxin gene along with key accessory virulence determinants (pfoA, colA, and cloSI). Phylogenomic analysis based on core single-nucleotide polymorphisms revealed that strain CQ1 is clustered into a distinct, independent evolutionary lineage with an existing historical yak isolate and a canine-origin isolate. Intraperitoneal challenge in mice confirmed its extreme lethality, causing 100% mortality within 36 h with severe intestinal necrosis. These findings provide fundamental genetic resources for understanding the virulence mechanisms and genetic background of this pathogen and offer critical insights for preventing and controlling clostridial diseases in high-altitude yak farming. Full article

The Qinghai–Tibet Plateau presents extreme environmental challenges, including hypobaric hypoxia and nutritional scarcity, to which indigenous yaks (Bos grunniens) are remarkably adapted, whereas introduced Holstein cattle (Bos taurus) often exhibit severe maladaptation. This study compared the gut microbiota of grazing yaks (n = 20) and feedlot Holstein cattle (n = 20) under high-altitude conditions using 16S rRNA gene amplicon sequencing (for community composition) and shotgun metagenomic sequencing (for direct functional profiling of CAZy, COG, and KEGG pathways), combined with in vitro fermentation, digestive enzyme assays, and serum immune- and growth-related indicators. Results: The yak gut microbiota was dominated by Proteobacteria (35 ± 4%) and Actinobacteria (15 ± 2%), whereas Holstein cattle were dominated by Firmicutes (40 ± 4%) and Bacteroidetes (25 ± 3%). At the species level, NR-based metagenomic annotation suggested that Acinetobacter-related taxa, putatively assigned as Acinetobacter pseudolwoffii and A. lwoffii, were abundant in yaks. Functional profiling revealed that the yak microbiota was enriched in CAZy families CE1, GT2, and GT4, whereas the feedlot Holstein cattle microbiota showed enrichment of several KEGG orthologs related to multidrug efflux and carbohydrate transport, including dinF/mepA/vmrA and susC/susD. In vitro fermentation using enriched culturable fecal bacterial consortia showed higher dry matter digestibility and digestive enzyme activities in yak-derived consortia than in Holstein-derived consortia. For serum immune indicators, IgG was significantly higher in feedlot Holstein cattle, whereas IgA and IgM did not differ significantly between groups. Yaks showed higher serum levels of TNF-α, IL-6, TGF-β1, IL-4, IL-10, and IL-13, but lower IL-1β. Conclusions: These findings indicate that divergent gut microbiota configurations are associated with contrasting physiological profiles (e.g., digestive and immune functions) in grazing yaks and introduced feedlot Holstein cattle under the same high-altitude environment. However, due to the confounding effects of diet and management system, causal relationships cannot be inferred from this comparative study. Full article

Yaks (Bos grunniens) are large mammals endemic to the Qinghai–Tibet Plateau. Efficient lung development is crucial for their adaptation to high-altitude hypoxia. As progenitor cells of the alveoli, type II alveolar epithelial (AT2) cells warrant further investigation into their physiological functions; however, relevant studies remain limited. In this study, primary AT2 cells were isolated from the lungs of yaks. Concurrently, lung tissues were collected from yaks at distinct developmental stages to investigate the role of the EGF/EGFR axis in regulating AT2 cell proliferation and apoptosis, as well as its essential contribution to yak lung development. Here, we demonstrate that the EGF/EGFR axis plays a beneficial role in yak alveolar development. Exogenous EGF supplementation or EGFR activation upregulated the downstream factors AKT and STAT3, enhanced AT2 cell proliferation, and reduced apoptosis. In contrast, EGFR inhibition promoted AT2 cell apoptosis and suppressed proliferation. Cell cycle analysis revealed that both exogenous EGF and EGFR activation increased the proportion of AT2 cells in the S and G2 phases, whereas EGFR inhibition caused cell cycle arrest at the G0/G1 phase. Moreover, the expression of cell cycle regulators cyclin D1, CDK4, and CDK6 was upregulated, while p16 and p21 expression was downregulated. Further comparative analyses indicated that the EGF/EGFR axis positively contributes to alveolar development in juvenile yaks. Collectively, these findings confirm that in plateau environments, activation of the EGF/EGFR axis promotes AT2 cell proliferation and inhibits apoptosis, thereby facilitating alveolar development in juvenile yaks. A key limitation is the lack of parallel comparisons with low-altitude cattle and other plateau-endemic species (e.g., Tibetan sheep), which precludes definitive assessment of the specificity of the EGFR/EGF axis in yak AT2 cell proliferation and lung development. Full article

The Ili River Valley and adjacent Xinjiang regions contain introduced cattle, local cattle, and yak and therefore provide a useful regional system for examining cattle–yak genomic differentiation. Using whole-genome resequencing data from 79 individuals, we analyzed Angus (ANG), Simmental (SIM), Holstein (HOL), Xinjiang Brown Cattle (XH), Kazakh Cattle (KAZ), Altay White-headed Cattle (AWH), and yak (WY). The six domestic cattle groups were merged into a composite domestic cattle group (PTN, n = 69) and compared with WY (n = 10). Sequencing generated 2996.28 Gb of raw data and 2939.56 Gb of clean data. Alignment to the Bos taurus ARS-UCD1.2 reference genome yielded mapping rates of 96.71–99.78% and depths of 5.98×–17.26×. Genome-wide PTN-WY comparisons showed extremely high differentiation: the median weighted F_ST was 0.846 and the 95th percentile was 0.943. The joint F_ST–π scan identified 832 candidate highly differentiated windows and 533 unique ENSBTAG gene IDs, whereas the low-differentiation set contained only five windows and three genes. The longest contiguous highly differentiated segments were located on chromosomes 26, 29, 8, 21, and 7. WY had the highest median Tajima’s D (1.173) and the slowest LD decay, while KAZ had the lowest median Tajima’s D (0.345) and the fastest LD decay. Treemix supported non-tree-like covariance components, and PSMC indicated broadly similar deep-time demographic profiles across individuals. Overall, the dominant genomic signal between PTN and WY is deep phylogenetic divergence, with locally enhanced highly differentiated segments superimposed on this background. These segments were enriched for functions and pathways related to reproductive behavior, neuroendocrine regulation, circadian rhythm, and membrane transport, but they are not interpreted here as recent within-species selective sweeps. The results provide a cautious regional framework for conservation and breeding of bovine genetic resources in Xinjiang. Full article

This study investigates the genetic diversity, population structure, and adaptive differentiation of Yunnan native cattle (YNC) using whole-genome SNP data from 457 individuals, representing eight cattle populations and two closely related bovine species (Zhongdian yak and Dulong gayal). Genetic diversity analyses revealed a distinct latitudinal gradient from north to south, with the highest diversity observed in the northern Diqing (DQC) and Zhaotong (ZTC) populations. The observed population structure was largely consistent with geographic distribution, identifying distinct ancestral components and complex admixture patterns. Genome-wide selective sweep scans revealed several key candidate genes underlying local adaptation. Notably, GRIA4 and DUOXA2 were associated with cold tolerance in northern populations, and ST3GAL3 and MST1 were implicated in heat stress adaptation in southern populations. Genome-wide balancing selection analyses further detected significant loci, such as MGST1 and SLC36A1, where divergent haplotype frequencies reflected differential selective pressures on milk-related traits between northern and southern populations. Additionally, we detected signals of historical introgression from Zhongdian yak into DQC cattle, highlighting the introgressed gene SLIT3 as a potential candidate associated with high-altitude thermogenesis. Collectively, these results provide a comprehensive genomic framework for the management and conservation of indigenous bovine genetic resources in Southwest China. Full article

As the hybrid offspring of cattle and yak, cattle–yaks suffer from male sterility, manifesting as cascading spermatogenic failure. Despite the Y chromosome’s pivotal role in spermatogenesis, the absence of a high-quality yak Y assembly has long impeded mechanistic understandings from this perspective. Here, a near-complete 42.4 Mb yak Y chromosome is constructed through a multi-stage assembly strategy that integrates de novo assembly with pangenome graph construction and Hi-C guided refinement. By developing a rigorously standardized gene annotation pipeline for precise cross-species comparison, we find that yaks have undergone a greater expansion of Y-linked ampliconic genes than cattle. Integrating this ampliconic landscape with short-read and full-length transcriptomics further demonstrates that yaks exhibit a drastic 2-to-4-fold increase in transcriptionally active copies of spermatogenesis-related ampliconic genes (including TSPY1, ZNF280BY, HSFY and PRAMEY) relative to cattle. Given negligible homology outside the pseudoautosomal region and conservation of key meiotic proteins, we propose a ‘cis-trans regulatory mismatch’ model driven by divergent Y-linked amplification as a working hypothesis to explain the primary genetic mechanism of cattle–yak male sterility. Together, these findings offer critical insights for addressing cattle–yak male sterility and establish the Y chromosome as an active driver of reproductive isolation beyond its traditional degenerate characterization. Full article

Volatile fatty acids (VFAs), the primary end-products of microbial fermentation in the ruminant forestomach, supply approximately 70% of the host’s energy requirements and play a pivotal role in maintaining energy homeostasis. While the mechanisms governing ruminal VFA production, absorption, and metabolism are well-characterized in common ruminants like dairy and beef cattle, a systematic integration of these processes in yaks, an iconic species long-adapted to the extreme Qinghai–Tibet Plateau, remains incomplete. This review synthesizes current knowledge on the entire VFA pathway in the yak rumen, from production to tissue metabolism. We detail the critical roles of functional microbes, including fibrolytic bacteria and Prevotella, in VFA synthesis and how their activity is dynamically regulated by dietary composition and seasonal shifts. Building on the unique structural features of the yak rumen epithelium, the review analyzes VFA absorption mechanisms involving both passive diffusion and carrier-mediated transport. Furthermore, we systematically outline the metabolic fates and energy partitioning strategies of VFAs across the rumen epithelium, liver, and peripheral tissues. This synthesis aims to elucidate the highly efficient and adaptive physiological basis of VFA metabolism that underpins the yak’s exceptional ability to utilize energy under the low-energy conditions of the high-altitude environment. Ultimately, this work seeks to provide a theoretical foundation for understanding plateau-adapted energy efficiency and to inform precision nutritional strategies for ruminants in alpine regions. Full article

The bovine tongue is a complex and very important muscular and gustatory organ, yet a comprehensive understanding of its gustatory apparatus across diverse genetic resources remains elusive. In this study, we conducted a multidimensional analysis of the lingual morphology and taste bud (TB) distribution in 40 specimens from 12 representative bovine breeds and species across China, encompassing Bos taurus taurus (Taurine cattle), Bos taurus indicus (Zebu cattle), Bubalus bubalis (water buffalo), and Bos grunniens (domestic yak). Morphometric measurements and histological quantifications were integrated to evaluate the influence of species, sex, age, and geographical factors. Given the relatively limited sample size per breed, these findings are presented as exploratory research. Our results revealed that yak and water buffalo showed the most distinct morphological patterns of mechanical papillae compared to the other populations. Taurine and Zebu cattle displayed more similar lingual morphology traits. Although high phenotypic correlations were observed between lingual morphometric parameters and quantitative papillae indicators, factors such as age, altitude, and feeding methods showed minimal influence on lingual phenotypic variation within this cohort (p > 0.05). Furthermore, we constructed a topological atlas of TB distribution, revealing that TB distribution patterns are decoupled from macro-anatomical dimensions, highlighting the complexity of the bovine gustatory system. These findings provide a quantitative baseline for ruminant comparative anatomy and offer structural insights into the evolutionary adaptation and nutrient regulation mechanisms of diverse bovine species in varying environments. Full article

Milk is a primary source of vital nutrients and bioactive components fundamental to the growth and development of both newborn animals and humans. Produced by economically significant livestock species (including cattle, buffaloes, goats, sheep and camels), milk is a complex matrix rich in caseins, vitamins, fats, and proteins. Beyond its classical nutritional profile, milk serves as a pivotal vehicle for milk-derived extracellular vesicles (mEVs). These specialized food-derived EVs (fEVs) exert pleiotropic effects that resonate with the One Health paradigm, linking animal well-being and human nutrition to broader ecosystem stability. mEVs offer unique advantages, such as high biocompatibility and gastrointestinal stability, also rendering them potential therapeutic tools as drug delivery systems. However, challenges remain regarding the standardization of mEVs and the variability of their molecular cargo. This review provides a comprehensive comparative analysis of mEVs across a diverse taxonomic range, including bovines, water buffaloes, yaks, camels, goats, pigs, horses, donkeys, and humans, highlighting their distinct functional signatures. Indeed, a critical issue in mEV research is the isolation process: recommendations to minimize contamination from milk fat globules and casein micelles (which can cover EV signals) are given. Finally, current detection methods and instrumentation, with a specific focus on advancing flow cytometry (FC) approaches are discussed. Key insights include the use of conventional FC (with fluorescence triggering, the necessity of rigorous controls and calibration, and the utility of bead-based assays to overcome resolution limits) and imaging flow cytometry (IFC). In both technical approaches, the application of different EV generic fluorescent markers and the strategic selection of tetraspanins (i.e., CD9, CD63, CD81), is mandatory: we emphasize that selecting the correct antibody clones and accounting for inter-species cross-reactivity are essential steps for ensuring the accuracy and reproducibility of mEV research across mammalian species. Full article

The yak represents a distinct domestic animal species that predominantly inhabits the Qinghai–Tibet Plateau and adjacent areas, possessing considerable value in both scientific and economic contexts. Compared to animals that mainly dwell on plains, such as cattle, the sperm maturation process in yak exhibits a certain degree of species specificity to adapt to their unique reproductive needs in high-altitude environments. Serving as the main storage site for functionally competent sperm, the cauda epididymis plays an integral role in mediating their post-testicular maturation. MiRNAs are vital regulatory molecules in the epididymis, influencing sperm maturation by modulating gene expression after transcription. To investigate the unique regulatory mechanisms of sperm maturation in yak, this study compared the miRNA expression profiles in the cauda epididymis of yak and cattle using high-throughput small RNA (sRNA) sequencing. The comparative analysis identified and characterized sRNA populations in the cauda epididymis of yak and cattle, revealing a similar length distribution that peaked at 22 nt and a predominance of known miRNAs. Notably, eight miRNAs were found to be highly expressed in both species. Furthermore, the first-nucleotide bias differed significantly between known and novel miRNAs within each species. A total of 31 differentially expressed (DE) miRNAs were identified, with 11 upregulated and 20 downregulated in yak compared to cattle. Among these, bta-miR-1298 exhibited the most significant upregulation, while bta-miR-2344 displayed the most pronounced downregulation. Bioinformatic analysis linked the predicted target genes of these miRNAs to numerous critical signaling pathways, including calcium signaling, the mitogen-activated protein kinase (MAPK) signaling pathway, the Ras-associated protein 1 (Rap1) signaling pathway, and the cyclic guanosine monophosphate-protein kinase G (cGMP-PKG) signaling pathway. Furthermore, eight significantly DE miRNAs, including bta-miR-2443, bta-miR-503-3p, bta-miR-6517, bta-miR-2440, bta-miR-2431-3p, bta-miR-2436-3p, bta-miR-6523a, and bta-miR-6775, were predicted to target genes involved in various aspects of sperm structural and functional maturation. These aspects include flagellum formation, sperm motility, chromatin remodeling, acrosome reaction, acrosome structure, sperm capacitation, chemotaxis, and nuclear chromatin condensation. Multiple miRNAs and their corresponding predicted target genes were analyzed by quantitative real-time PCR (qPCR), demonstrating an inverse correlation between miRNA expression and target gene levels. These findings reveal a distinct, species-specific miRNA signature in the yak cauda epididymis, which suggests a potential contribution to regulating the epididymal luminal environment and the process of sperm maturation. This study provides preliminary foundational data for elucidating the differences in sperm maturation mechanisms between yak and cattle, and offers potential novel targets for improving reproductive efficiency in plateau livestock. Full article

Milk fat globule membrane (MFGM) phospholipids could promote the development of infants’ brain, nervous system and digestive system. This research conducted a comparative analysis of phospholipid composition in MFGM of colostrum from different bovine species (Holstein cattle, yak, and Buffalo), with a particular focus on analyzing phospholipid variations in yak MFGM across different lactation stages. Chromatographic quantification revealed phosphatidylcholine (PC) as the predominant phospholipid class (34.7–47.44%) in all examined species. Notably, Holstein cow milk contains significantly higher levels of phosphatidylethanolamine (PE). Distinct phospholipid profiles emerged between species: yak milk demonstrated significantly higher concentrations of sphingomyelin (SM), lysophosphatidylethanolamine (LPE), dimethylphosphatidylethanolamine (dMePE), and bis-methylphosphatidic acid (BisMePA), whereas buffalo milk showed preferential accumulation of phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylglycerol (PG), and lysophosphatidylcholine (LPC). Longitudinal analysis revealed dynamic changes in yak milk phospholipids during lactation: as the lactation period in-creases, PC, PS, LPC, LPE, methylphosphatidylcholine (MePC), BisMePA, and dMePE exhibited progressive decline, while PE, SM, PI and PG showed incremental increases. Analysis of phospholipid metabolism pathways indicates that yak colostrum supports early calf development by enriching phospholipids associated with immune and neuroprotection, while mature milk shifts toward maintaining membrane stability. These compositional characteristics position yak milk as a promising phospholipid-fortified alternative to human breast milk. Full article

Grain feeding is used to alleviate grazing pressure on the Tibetan Plateau. This study employed metabolomics and transcriptomics to elucidate the regulatory mechanisms of grain feeding on yak (Bos grunniens) meat quality, intramuscular fat, and amino acids. The results demonstrate that grain feeding significantly reduces meat shear force (11.05 vs. 18.98) and increases intramuscular fat content (1.48 g/100 g vs. 0.75 g/100 g). This is accompanied by elevated levels of monounsaturated and saturated fatty acids, alongside a decreased proportion of n-3 PUFAs, leading to a higher n-6/n-3 ratio of 5.13. Mechanistically, metabolomic analysis identified 83 differential metabolites, including flavor-related nucleosides, amino acids, and key lipids, such as palmitoleic and oleic acid, which collectively contribute to improved flavor and tenderness. Concurrently, transcriptomics revealed 1047 differentially expressed genes enriched in lipid metabolism pathways, including PPAR signaling, steroid biosynthesis, and glycerolipid metabolism. The PPAR signaling pathway plays a central role in coordinating lipid synthesis, and critical genes, such as PNPLA2, PPARA, SREBF1, and PRKAA1, were highlighted. In conclusion, grain feeding improves yak meat tenderness and fat deposition by modulating lipid metabolism at both the transcriptional and metabolic levels. This improvement, however, is balanced against a less favorable n-6/n-3 PUFA ratio. Full article

The growing demand for robust food authentication methods has driven the establishment of fast, sensitive, and field-based detection systems for identifying meat species. This study presents a colorimetric-based PSR approach for identifying yak (Bos grunniens) meat within fresh, thermally processed, and blended meat samples. Targeting the mitochondrial D-loop locus, the assay incorporates a simple alkaline lysis (AL) procedure for efficient DNA extraction, eliminating the requirement for specialized instrumentation. The PSR assay demonstrated high specificity, showing no evidence of cross-reactivity with closely associated food animals such as buffalo, cattle, goat, sheep, mithun, and pig. Sensitivity assessment revealed the assay’s capability to detect 1 pg of yak DNA, with reliable performance in samples exposed to thermal conditions up to 121 °C. Additionally, the technique detected yak meat down to a concentration of 0.1% in binary beef mixtures. This method provides a significant improvement in sensitivity over end-point PCR and is particularly well-suited for field applications due to its practical simplicity, affordability, as well as no reliance on sophisticated instrument. This is, to the best of our understanding, the first reported PSR-based approach developed for the identification of yak meat, offering a robust tool for food origin verification, regulatory enforcement, and product integrity monitoring. Full article