Skeletal myogenesis is an extremely complex process that mononuclear myoblasts undergo proliferation, differentiation, and fusion to form multinucleated contractile muscle fibers, involving a balance between synthesis and degradation metabolism. Skeletal muscle requires an effective mechanism to balance rapid proliferation by degrading supernumerary or damaged organelles/proteins, or by activating cellular signals to regulate subsequent muscle differentiation. In recent years, three important cellular processes-apoptosis, ubiquitin-proteasome system (UPS), and autophagy-have received extensive attention in skeletal myogenesis. The UPS supports the early differentiation process and initiates apoptosis, and the increase in apoptosis activates autophagy to clear damaged organelles and proteins, which in turn inhibits apoptosis, preventing excessive cell death and maintaining cellular stability. The coordination among apoptosis, UPS, and autophagy is more intricate, as they interact through a dynamic balancing mechanism, determining the balance between cell death and survival, and enabling proper muscle differentiation. Here, we explore the molecular signals that mediate apoptosis, UPS, and autophagy, with a focus on analyzing their interrelationship in skeletal myogenesis. Studying the regulatory mechanisms of these molecules will help in understanding the role of cell death in skeletal muscle development, especially how they affect muscle cell differentiation, providing new insights into mammalian skeletal myogenesis.

This study profiled the nutritional, safety, and metabolic evolution of milk from Chuanzhong Black (CBG) and Jianzhou Big-Ear (JBG) goats during early lactation (days 1-35). Results revealed that colostrum in both breeds contained superior levels of total solids, fat, and protein compared to mature milk. Notably, CBG colostrum exhibited significantly higher IgG concentrations (81.29 mg/mL) than JBG, indicating stronger passive immunity potential. However, safety analysis showed that Aflatoxin M1 (AFM1) concentrations also peaked in colostrum. Untargeted metabolomics identified 804 (in CBGs) and 790 (in JBGs) differentially expressed metabolites (DEMs), revealing a distinct functional shift from immunity-supporting compounds in colostrum to energy-provision metabolites in mature milk. Additionally, CBG generally displayed elevated metabolite levels compared to JBG. These findings confirm that milk quality is strictly governed by both breed and lactation stage, providing valuable metabolic insights for evaluating milk quality and establishing baseline grading standards for meat goats.

Background Intramuscular fat (IMF) is a critical determinant of rabbit meat quality, influencing tenderness, juiciness, and flavor. miRNAs are crucial for IMF synthesis by regulating genes involved in lipid deposition, but the mechanisms by which miRNAs regulate IMF deposition in rabbits remain poorly understood. This study aimed to investigate the role of microRNAs (miRNAs) in IMF deposition in Hycole rabbits (HR) and Rex rabbits (RR) at three developmental stages (35, 75, and 150 days of age) using small RNA sequencing. Results A total of 195 differentially expressed (DE) miRNAs were identified in HR across the three stages, including 49 co-expressed DE miRNAs (e.g., ocu-miR-29c-5p, ocu-miR-382-3p, ocu-miR-29b-3p). In RR, 222 DE miRNAs were detected, with 45 co-expressed DE miRNAs (e.g., ocu-miR-182-5p, ocu-miR-486-5p, ocu-miR-370-5p). Comparative analysis between breeds identified 128 DE miRNAs, but none were co-expressed. GO and KEGG enrichment analyses showed DE miRNAs and their target genes were significantly enriched in pathways like PI3K-Akt, MAPK, Hippo, and HIF-1, which were closely associated with lipogenesis, metabolism, and obesity. Conclusions This study elucidates the transcriptional regulatory mechanisms of IMF deposition in rabbits and identifies key miRNAs influencing IMF accumulation. Our findings provide new insights into the molecular mechanisms underlying rabbit IMF deposition and offer important resources to support future genetic improvement and management strategies in rabbit production.

Yaks have long inhabited the Qinghai-Tibetan Plateau. This region features low-oxygen, frigid temperatures and pronounced seasonal variation in nutrient availability. They have evolved adaptive phenotypes centered on energy metabolism reprogramming, tissue structure remodeling, and stress homeostasis maintenance. In recent years, non-coding RNAs (ncRNAs) have been confirmed as an important component of the yak’s post-transcriptional regulatory network. They play a key bridging role between environmental stress perception and phenotypic output through mechanisms such as influencing RNA splicing, stability, translation activity, and constructing competitive endogenous RNA (ceRNA) networks. This article systematically reviews the biogenesis pathways and core regulatory patterns of circular RNAs (circRNAs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). It focuses on summarizing the expression profile characteristics and dynamic spatiotemporal changes of these three types of ncRNAs in physiological contexts such as muscle and fat deposition, mammary gland lactation, testicular development, and hypoxia response in the heart, lungs, and vascular system of yaks. Current research evidence indicates that the regulatory network of yaks ncRNAs shows significant convergence on multiple key signaling pathways, mainly concentrating on lipid metabolism (PPAR/AMPK), nutrition and growth signals (PI3K-Akt/MAPK/mTOR), extracellular matrix remodeling (ECM-receptor interaction, Wnt/TGF-β), and cell stress fate determination (apoptosis, oxidative stress/ferroptosis) modules. Among them, some core circRNA and lncRNA-miRNA-mRNA regulatory axes have been functionally validated in vitro. Despite the phased progress, current research on ncRNA in yaks still faces bottlenecks: the multi-omics molecular atlases (encompassing genomics, transcriptomics, proteomics, and metabolomics) of key high-altitude adaptive organs remain incomplete, analysis processes lack sufficient standardization, and most studies stay at the association network level with limited causal mechanism validation. To address these limitations, future research should focus on building a standardized evidence chain, integrating multi-omics and single-cell/spatial transcriptome technologies, and conducting mechanism verification for traits in independent populations, thereby providing a solid theoretical basis for understanding the extreme environmental adaptation mechanisms of yaks and molecular breeding improvement.

Intramuscular fat (IMF) is a pivotal determinant of meat quality in yaks (Bos grunniens). While nutritional factors are well-documented, the epigenetic landscape, particularly the transcriptional architecture governed by super-enhancers (SEs), remains largely unexplored in the context of IMF deposition. To investigate SE-associated genes, Chromatin immunoprecipitation sequencing (ChIP-seq) assays using H3K27ac antibodies and RNA-sequencing (RNA-Seq) were conducted on longissimus dorsi (LD) muscle tissues with high and low IMF contents. Integrated multi-omics analysis identified 82 enhancer-associated genes exhibiting significant upregulation in high-IMF samples, with 63 loci characterized as SE-associated. In particular, H3K27ac signal distribution analysis indicated that SEs were distributed across functional regions such as promoters, gene bodies, exons, and introns. Among these SE-related genes, 3-hydroxybutyrate dehydrogenase 1 (BDH1) was further investigated to understand its function and regulatory mechanisms. To address this, overexpression or knockdown experiments were conducted, followed by CCK-8, EdU, Bodipy functional assays, and Real-time quantitative PCR (RT-qPCR) analysis. Functional experiments revealed that BDH1 acts as a key positive regulator of yak preadipocyte differentiation and is a prime SE-associated candidate regulatory gene. Furthermore, dual-luciferase reporter assays were performed to identify its SE region, revealing that the activity of 4 enhancer regions was significantly upregulated. Collectively, these findings implicate SE-associated genes in IMF deposition in yaks, provide a valuable resource for future research, and underscore the functional relevance of BDH1 in this process.

Hypertension represents a major global public health challenge and is the primary risk factor for target organ damage (TOD), including cardiovascular disease, stroke, and chronic kidney disease. Extracellular vesicles (EVs), as a class of nanoscale membrane structures secreted by cells that encapsulate bioactive molecules such as proteins, nucleic acids, and lipids, have emerged as key mediators of intercellular communication. Increasing evidence in recent years indicates that EVs play a pivotal role in the pathophysiology of hypertension development, target organ damage, and associated complications. They regulate key pathological processes—including endothelial function, inflammatory responses, vascular remodeling, and fibrosis—through their specific cargo (e.g., microRNAs, proteins). This review systematically summarizes recent advances in extracellular vesicle research concerning hypertension and target organ damage, emphasizing the molecular mechanisms of EVs in hypertension and its cardiovascular, renal, and pulmonary circulatory target organ damage, as well as their potential as biomarkers, thereby laying the foundation for future clinical applications.

Although large-scale studies and potential pathways of genes on intramuscular fat (IMF) in livestock have been reported, research on circRNAs in yaks-a unique, low-IMF-content animal species that is native to the Qinghai-Tibetan Plateau-is still lacking. Based on previous high-throughput sequencing results on longissimus dorsi with different IMF content, a novel circRNA encoded by the VPS13C gene (designated as circVPS13C) was found to exhibit significant differential expression. Here, we systematically characterized the function and mechanism of circVPS13C on IMF deposition in yaks by adopting a series of experiments. Sequencing, RNase R processing, and nucleoplasmic separation experiments confirmed the circular structure feature of circVPS13C, and it was predominantly distributed in the cytoplasm. Furthermore, these experiments demonstrated that circVPS13C was mainly distributed in the cytoplasm. The circVPS13C/miR-5606-x/ECHDC3 axis was constructed through ceRNA network analysis and validated by dual-luciferase reporter and rescue experiments. Furthermore, the function of these three potential regulators during IMF deposition was investigated through CCK-8, BODIPY, Oil Red O staining, and qRT-PCR analyses, and results showed that both circVPS13C and miR-5606-x promoted the differentiation and inhibited the proliferation of yak intramuscular preadipocytes, while the function of ECHDC3 was the opposite. In conclusion, circVPS13C could act as a competitive endogenous RNA (ceRNA) sponge to sequester miR-5606-x, thereby relieving the inhibitory effect of miR-5606-x on ECHDC3.

[This corrects the article DOI: 10.3389/fvets.2023.1272238.].

Emerging evidence suggests that mitochondrial-nuclear genomic crosstalk plays a role in phenotypic regulation. However, the molecular mechanisms underlying functional gene coordination and the dynamics of regulatory networks remain incompletely characterized. In the present study, we established bovine cybrid models harboring isogenic nuclear genomes but distinct mitochondria adapted to different environmental oxygen tensions. Multi-omics analyses identified 437 DEmRNAs, 48 DElncRNAs, 169 DEcircRNAs, 154 DEmiRNAs, and 91 DEPs between the isonuclear cybrids with different mitochondrial backgrounds. Reconstruction of the regulatory network elucidated two ceRNA networks consisting of 112 mRNAs, 11 miRNAs, and 21 lncRNAs. Cross-omics integrative analysis revealed 37 concordantly regulated targets that exhibited significant expression alterations at both transcriptional and translational levels, including DSG3, DSC2, ISG15, and IGFBP2. Functional enrichment analysis indicated that these molecular determinants were critically involved in steroid biosynthetic processes, cGMP-PKG signal transduction, and NLR-mediated inflammatory responses. Collectively, our findings demonstrate that mitogenomes orchestrate cellular energy homeostasis and hypoxic adaptation through synergistic regulation of nuclear gene expression and post-translational modifications.

High-altitude hypoxia poses a sustained energetic and oxidative challenge to the heart, often leading to mitochondrial dysfunction and metabolic inflexibility in nonadapted mammals. Yaks (Bos grunniens) exhibit remarkable cardiac tolerance to chronic hypoxia; however, the underlying intracellular mechanisms remain poorly defined. Herein, we identify A-kinase anchoring protein 1 (AKAP1) as an important regulator of hypoxia tolerance in yak cardiac fibroblasts. Through the genetic manipulation of AKAP1 combined with live-cell mitochondrial imaging, functional assays, and untargeted metabolomics, we demonstrate that AKAP1 confers a robust survival advantage under hypoxic stress. AKAP1 preserves mitochondrial membrane potential, maintains ATP production, limits reactive oxygen species accumulation, and sustains cell viability. Mechanistically, AKAP1 stabilizes mitochondrial network integrity by restoring the balance between fission and fusion, particularly by suppressing excessive fission. At the metabolic level, AKAP1 orchestrates cellular metabolic reprogramming, modulates lipid metabolism, maintains energetic flexibility, and regulates cAMP-associated pathways. These findings provide new insights into the molecular mechanisms underlying hypoxic stress tolerance in yaks and highlight the potential role of AKAP1 in maintaining mitochondrial homeostasis and metabolic flexibility under oxygen-limited conditions.

This study explored the patterns and mechanisms influencing changes in silage quality, mycotoxin accumulation, and microbial community structure in oat silage after lodging. Upright oat forage (control, CK), lodging oat forage (upper layer (UL), lower layer (LL), and mixed layers (MLs) were harvested at 0, 7, 25, and 45 days after lodging and ensiled for 60 days. The results showed that the dry matter (DM) and water-soluble carbohydrate (WSC) content decreased significantly (p < 0.05), whereas crude protein (CP) and fiber content increased significantly compared to upright oats (p < 0.05). The WSC and CP content in silage decreased with increasing lodging duration. The fiber content increased in late harvest after lodging. The risk of mycotoxin infection increased after lodging, with aflatoxin levels exceeding EU limits. The mycotoxins in UL silage were the lowest when lodging lasted for seven days. Lodging oat silage was dominated by Lactobacillus, and the Pseudomonas in the lodging group was less than 4%. The fungi in lodging oat silage was lower, and the UL (upper layer) treatment was the lowest when lodging for 7 days. Overall, the transfer of microorganisms, especially Plectosphaerella, Fusarium, Alternaria, Cladosporium, and Botryotrichum, from soil to silage following oat collapse is of interest. The results suggest the soil-plant microbial interactions and their effects on silage fermentation and mycotoxins in lodging oats.

Through long-term natural and artificial selection, yaks (Bos grunniens) have evolved diverse coat colors with important aesthetic and economic value. Previous studies indicate that these traits may also serve as important indicators of adaptation to cold, high-altitude environments. However, the genetic mechanisms underlying these traits remain unclear. Here, we systematically analyzed the genetic architecture of coat color in 511 yaks by combining red-green-blue (RGB)-based quantitative phenotyping with the QingXin 1st 30 K single nucleotide polymorphism (SNP) genotyping chip. RGB components were highly correlated within body regions, but moderately correlated between the head and rump, indicating region-specific pigmentation patterns. Genome-wide association studies (GWAS) of head and rump coat color using five models (general linear model (GLM), mixed linear model (MLM), multiple loci mixed model (MLMM), fixed and random model circulating probability unification (FarmCPU), and Bayesian information and linkage disequilibrium (LD) iteratively nested keyway (BLINK)), together with genotype-by-environment interaction (GbyE) analyses revealed region-specific genetic regulation. Candidate genes associated with yak coat color included KIT and DISP3. KIT was detected in both GWAS and GbyE analyses, underscoring its potential key role in coat color. Heritability (h2) was higher for the head coat color (42.8

The intramuscular fat (IMF) content of yak beef is critical for determining its quality. Circular RNAs (circRNAs) are a group of endogenous non-coding RNAs that have emerged as important factors in the regulation of IMF deposition. However, the molecular mechanisms through which circRNAs regulate IMF deposition, particularly in yaks, remain unclear. In the present study, a novel circRNA, circCDK14 (originating from the yak’s CDK14 gene), was identified by sequencing and RNase R treatment. In our previous study, we successfully established a ceRNA network map and identified miR-4492-z, which interacts with circCDK14. Furthermore, using methylation prediction software, we predicted two genes, SRSF3 and hnRNP A1, that have a strong binding relationship with circCDK14; existing research has confirmed their close association with m6A methylation modifications. On the basis of these findings, we comprehensively evaluated the effects of circCDK14, miR-4492-z, SRSF3 and hnRNP A1 on the proliferation and differentiation of yak intramuscular pre-adipocytes using EdU, CCK-8, BODIPY, Oil Red O and qRT-PCR analyses. Mechanistically, the interaction between circCDK14 and miR-4492-z was validated using a dual-luciferase reporter gene assay and rescue experiments. RIP assays revealed the binding interaction of circCDK14 with SRSF3 and hnRNP A1. The MeRIP experiments showed modification of circCDK14 methylation, with SRSF3 and hnRNP A1 promoting the methylation and translocation of circCDK14 from the nucleus to the cytoplasm. In summary, our results suggest that m6A-modified circCDK14 plays a crucial role as an miR-4492-z sponge in regulating IMF deposition in yaks and that the nuclear export of circCDK14 correlates with the expression levels of SRSF3 and hnRNP A1. This study provides a theoretical basis for the improvement of yak meat quality and promotes the development of molecular yak breeding.

Skeletal muscle is the most widespread tissue in mammals and mediates several functions, and whose development is controlled by a coordinated transcriptional hierarchy that regulates the activities of a range of muscle genes. Skeletal muscle comprises various cells that create communication strategies for exchanging biological information. Nevertheless, the features and developmental programs of several of these cell lines remain unknown. We constructed a complete single-cell landscape of prenatal to postnatal developing bovine skeletal muscle and compared its single-cell transcriptomic characteristics with those of humans and mice. This landscape involved cellular heterogeneity, dynamic gene expression profiles, critical regulons during cell fate decisions, extensive networks of intercellular communication, and a gene regulation network. Overall, our results identify a developmental coordinate of the pluripotency spectrum among bovines, humans, and mice. This finding suggests evolutionary conservation and species-specific differences in the skeletal muscle systems, extending to cell types, gene expression, and regulatory elements. These results offer insights into evolutionary conserved and divergent processes during mammalian skeletal muscle development.

Circular RNAs (circRNAs) play a crucial role in post-transcriptional regulation during the development and physiology of mammals. However, the role of superenhancer (SE)-associated circRNAs (SE-circRNAs) in adipogenesis remains largely unexplored. In this study, RNA and H3K27ac chromatin immunoprecipitation sequencing analyses of yak muscle tissues with varying IMF contents were performed, and 81 differentially expressed SE-circRNAs were identified in the high IMF (intramuscular fat) group. Among them, circRHOQ was notably associated with SEs, with H3K27ac signals enriched at its genomic locus. Enhancer activity assays identified two key regulatory regions (chr9:49134487-49135239 and chr9:49136018-49136614) with significant transcriptional activation. Treatment with JQ-1 suppressed circRHOQ expression, confirming that circRHOQ is an SE-driven regulatory circRNA. Functional assays validated that circRHOQ is a cytoplasmic circRNA that promotes yak intramuscular preadipocyte adipogenic differentiation, as indicated by the increased lipid accumulation, triacylglycerol content, and adipogenic gene expression. Mechanistically, circRHOQ acts as a competing endogenous RNA by binding to miR-5093, thereby derepressing its target IRF5 and promoting adipogenesis. Dual-luciferase assays validated the direct interactions among circRHOQ, miR-5093, and IRF5. This study revealed that circRHOQ promotes yak IMF development via the SE-circRHOQ/miR-5093/IRF5 axis, thus providing a basis for further investigation into IMF deposition and improvement of high-altitude livestock breeds.

The yak (Bos grunniens) has exceptional hypoxia resilience, making it an ideal model for studying high-altitude adaptation. Here, we investigated the effects of oxygen concentration on yak cardiac fibroblast proliferation and the underlying molecular regulatory pathways using RNA sequencing (RNA-seq) and metabolic analyses. Decreased oxygen levels significantly inhibited cardiac fibroblast proliferation and activity. Intriguingly, while the mitochondrial DNA (mtDNA) content remained stable, we observed coordinated upregulation of mtDNA-encoded oxidative phosphorylation components. Live-cell metabolic assessment further demonstrated that hypoxia led to mitochondrial respiratory inhibition and enhanced glycolysis. RNA-seq analysis identified key hypoxia adaptation genes, including glycolysis regulators (e.g., HK2, TPI1), and hypoxia-inducible factor 1-alpha (HIF-1α), with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses highlighting their involvement in metabolic regulation. The protein–protein interaction network identified three consensus hub genes across five topological algorithms (CCNA2, PLK1, and TP53) that may be involved in hypoxia adaptation. These findings highlight the importance of metabolic reprogramming underlying yak adaptation to hypoxia, providing valuable molecular insights into the mechanisms underlying high-altitude survival.

Membrane-less condensates (MLCs) are highly concentrated non-membrane-bounded structures in mammalian cells, comprising heterogeneous mixtures of proteins and/or nucleic acids. As dynamic compartments, MLCs can rapidly exchange components with the cellular environment, and their properties are easily altered in response to environmental signals, thus implicating that they can mediate numerous critical biological functions. A basic understanding of these condensates’ formation, function, and underlying biomolecular driving forces has been obtained in recent years. For example, MLCs form through a liquid-liquid phase separation (LLPS) phenomenon similar to polymer condensation, which is primarily maintained via multivalent interactions of multi-domain proteins or proteins harboring intrinsically disordered regions (IDRs) as well as RNAs with binding sites. Moreover, an accumulating body of research indicates that MLCs are pathophysiologically relevant and involved in gene expression regulation and cellular stress responses. Here, we review the emerging field and explore what is currently known about the varied progress in LLPS of MLCs and how their features affect various cellular process, focusing on RNAs, including in skeletal myogenesis.

Intramuscular fat (IMF) is a critical determinant of meat quality in rabbits, influencing attributes such as tenderness, juiciness, and flavor. A moderate increase in IMF content is associated with enhanced meat quality. In this study, we evaluated the growth performance, slaughter performance, and meat quality traits of the longissimus dorsi (LD) muscles in Hycole and Rex rabbits across various growth stages. Utilizing transcriptome sequencing, we identified and analyzed differentially expressed mRNAs (DE mRNAs) and long non-coding RNAs (DE lncRNAs), and constructed lncRNA-mRNA regulatory networks to investigate candidate genes influencing IMF content in Rex rabbits at different developmental stages. The results demonstrated an age-dependent increase in IMF content for both breeds, with Rex rabbits consistently exhibiting higher IMF levels compared to Hycole rabbits at equivalent ages. Through whole transcriptome sequencing, we identified several DE mRNAs and DE lncRNAs associated with fat deposition across various developmental stages and breeds. These include KCNQ5, POSTN, TMEM182, CASQ2, ME1, and COL6A6, as well as lncRNAs such as TCONS_00009631, TCONS_00082976, TCONS_00040377, TCONS_00051990, and TCONS_00069025. Enrichment analysis revealed that these genes are implicated in key signaling pathways related to fat deposition, including the Wnt, TGF-β, and PPAR signaling pathways. RNA sequencing data further revealed that age significantly impacts IMF deposition, with the most pronounced differences observed between 35-day-old and 150-day-old rabbits. Additionally, through comprehensive lncRNA-mRNA regulatory network, short time-series expression miner (STEM) analyses, and weighted gene co-expression network analysis (WGCNA), we identified 10 lncRNA-mRNA target gene pairs associated with IMF deposition, including critical genes implicated in fat accumulation such as STARD13, HSPB8, and CBLB. This work provided regulatory networks of rabbits and revealed STARD13, HSPB8, and CBLB as the key genes responsible for IMF deposition. Our findings highlight that IMF deposition in rabbits triggers dynamic transcriptional alterations. These findings provide a robust theoretical foundation for advancing genetic breeding strategies and elucidating the regulatory mechanism underlying adipose development in rabbits.

BACKGROUND:The yak is a unique livestock species bred on the Qinghai-Tibet Plateau. We utilized genotypic data obtained from the yak sequencing chip "Qingxin-1" and phenotypic data measured from image photographs using conversion between pixel and distance. The primary objective of this study was to conduct genome-wide association studies (GWAS) using five models to analyze seven body size traits. Specifically, the goals were to (1) characterize the genetic structure of three major yak breeds: Maiwa, Yushu, and Huanhu; (2) identify candidate genes that significantly influence yak body size traits; and (3) compare the prediction accuracy of single-trait and multi-trait genomic selection(GS). RESULTS:A total of 94 markers were significantly (P<1e-05) associated with yak body size traits. GWAS results revealed that PRKAA2 and SNX9 were important candidate genes affecting the body size traits of yaks. The GS results indicated that combining marker-assisted selection and best linear unbiased prediction significantly improved the accuracy of predicting body size traits, the average accuracy in multi-trait GS was higher than that in single-trait GS. CONCLUSIONS:Our findings provide valuable insights into the genetic architecture underlying yaks, with implications for the development and selection of yak body size traits. The identification of key genes such as PRKAA2 and SNX9 offers promising targets for breeding programs aimed at optimizing body size traits, thereby supporting genetic improvements in yak populations.

Runs of homozygosity (ROH) are continuous segments of homozygous genotypes inherited from both parental lineages. These segments arise due to the transmission of identical haplotypes. The genome-wide patterns and hotspot regions of ROH provide valuable insights into genetic diversity, demographic history, and selection trends. In this study, we analyzed whole-genome resequencing data from 117 rabbits to identify ROH patterns and inbreeding level across eleven rabbit breeds, including seven Chinese indigenous breeds and four exotic breeds, and to uncover selective signatures based on ROH islands. We detected a total of 31,429 ROHs across the autosomes of all breeds, with the number of ROHs (NROH) per breed ranging from 1316 to 7476. The mean sum of ROHs length (SROH) per individual was 493.84 Mb, covering approximately 22.79