Search Results (51)

To identify molecular markers associated with wool traits in fine-wool sheep, we examined genetic polymorphisms in the NOTCH2 and CD1A genes in 944 Subo Merino sheep in this study. Subsequently, we performed association analyses between mutation sites in the NOTCH2 and CD1A genes and wool traits using SAS 9.4 software, followed by linkage disequilibrium (LD) analysis of different mutation sites using Haploview 4.2 software. Additionally, bioinformatics tools were employed to predict the potential impacts of missense mutations on protein secondary and tertiary structures. Finally, quantitative PCR (qPCR) was used to assess the expression levels of the NOTCH2 and CD1A genes. Genetic analysis revealed six polymorphic sites in NOTCH2 and CD1A, all of which were missense mutations. Two SNPs in NOTCH2 (SNP1 and SNP2) showed significant associations with the coefficient of variation of fibre diameter, and SNP1 was also associated with greasy fleece weight. Four SNPs in CD1A (SNP3–SNP6) were significantly associated with fibre diameter standard deviation, and SNP3, SNP4, and SNP5 were additionally associated with crimp number. LD analysis revealed that SNP3, SNP4, and SNP5 were closely linked. Bioinformatics analysis indicated that the mutations caused alterations in the secondary and tertiary structures of the NOTCH2 and CD1A proteins. qPCR results showed that the CD1A gene was highly expressed in the fine wool fibre group compared with the ultra-fine wool fibre group. In conclusion, this study revealed a genetic association between NOTCH2 and CD1A and wool traits. The results are expected to provide a theoretical foundation for breeding wool traits in Subo Merino sheep, thereby enhancing the economic value of fine wool. Full article

The keratin-associated proteins (KAPs) are a class of wool proteins. They form a matrix that cross-links the wool intermediate filament keratins. The KAPs are thought to affect wool fibre structure and properties and have been associated with variation in wool fibre traits. There are many KAP genes in sheep, but not all have been identified. Recently a second member of the KAP22 gene family, KRTAP22-2, was identified in goats, and variation in this caprine gene was associated with cashmere fibre traits. In this study, we identified ovine KRTAP22-2. To ascertain the extent of variation in KRTAP22-2, sheep from eight breeds were investigated using polymerase chain reaction (PCR) followed by single-strand conformational polymorphism (SSCP) analysis. This revealed two unique banding patterns, which upon sequencing gave two novel DNA sequences. These differed by two single nucleotide polymorphisms in the coding region. Three genotypes of the novel KRTAP22-2 sequences were observed in the eight sheep breeds studied. The ovine KRTAP22-2 variant sequences were similar to a goat KRTAP22-2 variant, but a search of ovine expressed sequence tags revealed no matching mRNA sequences in the ovine databases. In a second part of the study, no association was found between the KRTAP22-2 genotypes and mean fibre diameter, fibre diameter standard deviation, coefficient of variation in fibre diameter, and mean fibre curvature, for either the fine wool or heterotypic hair fibres of 255 Chinese Tan lambs. These results suggests that sheep have a KRTAP22-2 gene, but that there may be species-specific differences in the gene’s expression or function. The gene may not affect wool traits in the way that it appears to in goats. Full article

This study evaluated marbling and meat quality traits in lambs of three genotypes under a uniform high-energy fattening regimen. Male lambs (6–7 months old, n = 12 per group) from purebred Kazakh Finewool (control) and two independent Suffolk × Kazakh Finewool F₁ crossbred lines (Groups 1 and 2) were fed identical diets and raised under the same conditions. Meat samples were analyzed for composition, fatty acid profile, micronutrients, color, visual marbling, and microbiological safety. Group 2 crossbreds had significantly higher intramuscular fat (~9.0%) than the controls (~6.5%) (p < 0.05), with corresponding increases in monounsaturated and polyunsaturated fatty acids. Vitamin A, vitamin E, and zinc levels were also higher in Group 2 (p < 0.05), while other nutrients were similar across groups. All samples had normal pH (~5.7–5.8) and high water activity (~0.985) and met microbial safety standards. Visual marbling was more pronounced in crossbreds, and meat color remained bright red with no significant group differences in redness (a value). These findings suggest that crossbreeding Kazakh Finewool with Suffolk sheep, combined with controlled grain fattening, enhances marbling and nutritional traits without compromising safety or appearance, offering a viable approach to improving lamb meat quality. Full article

Various signalling molecules and pathways critical for wool production and quality regulate wool secondary follicle (SF) development. Circular RNAs (circRNAs) regulate SF morphogenesis through a competing endogenous RNA (ceRNA) mechanism; these novel cyclic non-coding RNAs are not known to regulate the development of SFs in the foetal period of fine-wool sheep. Here, we analysed circRNA expression profiles in the foetal skin of Gansu Alpine fine-wool sheep at 10 developmental stages (E87, E90, E93, E96, E99, E102, E105, E108, E111, and E138) using RNA sequencing. Among the differentially expressed circRNAs (DE circRNAs), 173 were significantly enriched in signalling pathways related to hair follicle (HF) development, such as Wnt/β-catenin, transforming growth factor-β/Smad, Notch, and mitogen-activated protein kinase. Six HF-development-related circRNAs were expressed at different stages and potentially regulated SF development through the ceRNA network. In total, 16 DE circRNAs and their targets, 44 miRNAs, and 65 mRNAs were screened, and 88 ceRNA regulatory network pathways related to SF development were constructed. These key DE circRNAs could be candidate genes for further exploration of the molecular HF development mechanism, providing an important theoretical basis for unravelling the regulatory network of SF development in fine-wool sheep and genetic wool trait improvement. Full article

Fiber fineness is a critical determinant of wool quality and is of great significance in enhancing the overall quality of wool. The aim of this research was to pinpoint the key proteins that participate in the regulation of wool fineness. To achieve this, we utilized Astral—DIA proteomics technology to examine the disparities in proteins, pathways, and GO terms among the wool tissues of Gansu alpine fine-wool sheep with varying mean fiber diameters (MFD). The experiment was divided into two groups: coarse (group C, MFD = 22.36 ± 0.75 μm, n = 4) and fine (group F, MFD = 16.89 ± 0.36 μm, n = 4). The results indicated that 67 differentially expressed proteins (DEPs) were identified from the wool tissues of Gansu alpine fine-wool sheep in groups C and F. Functional enrichment analysis demonstrated that several key differential proteins, including MGST3, KRT26, KRT72, KRT74, KRT71, etc., were mainly enriched in multiple functional pathways. These pathways included glutathione metabolism, oxidative phosphorylation, the degradation of valine, leucine, and isoleucine, intermediate filaments, serine protease activity, and cysteine protease activity (p < 0.05). Furthermore, protein–protein interaction (PPI) network analysis suggested that type II keratin and type I keratin (such as CTSF, PSAP, TMEM106B, LYPD3, KRT71, KRT72), along with glutathione metabolism (MGST3, W5QDB7), are closely related to hair follicle development and the regulation of wool fineness. In summary, this study enriches the existing sheep proteinome database and offers novel perspectives on the regulatory mechanisms of wool fineness. Full article

In this study, 944 Subo Merino sheep, a high-quality fine wool breed, were selected as research subjects. The SNP typing of the FAT3 gene was performed using the Fluidigm BiomarkTM HD system, and 11 missense mutation sites were identified. The analysis of population polymorphism of single-nucleotide polymorphisms was conducted. It is noteworthy that a substantial strong linkage disequilibrium was identified between SNP 5 and SNP 6 (r² > 0.8). The association between SNPs of the FAT3 gene and wool traits showed that multiple SNPs were significantly correlated with several different wool traits (p < 0.05). Furthermore, the investigation delved into the impact of the FAT3 gene on wool fiber through the utilization of quantitative polymerase chain reaction (qPCR), which yielded findings that this gene was notably expressed in fine wool fiber (FW) (p < 0.001). To predict the subcellular localization and protein transmembrane structure of FAT3, we employed the PSORT II Prediction and TMHMM online software. It was determined that the protein contains a transmembrane domain. This study provides molecular markers for the improvement of the selection and breeding of ultrafine-wool sheep and offers experimental evidence for accelerating the genetic breeding of sheep. Full article

Wool has distinctive biological, physical, and chemical properties that contribute to its value both for the sheep and in global fibre and textile markets. Its fibres are primarily composed of proteins, principally keratin and keratin-associated proteins (KAPs). To better comprehend the genes that underpin key wool traits, this study examined the keratin-associated protein 36-1 gene (KRTAP36-1) in Chinese Tan lambs. We identified three previously reported alleles of the gene (named A, B and C) that were present in the lambs studied, with genotype frequencies as follows: 2.0% (n = 5; AA), 6.9% (n = 17; AB), 13.8% (n = 34; AC), 8.9% (n = 22; BB), 33.4% (n = 82; BC) and 35.0% (n = 86; CC). The frequencies of the individual alleles in the Chinese Tan lambs were 12.4%, 29.1% and 58.5% for alleles A, B and C, respectively. The three alleles were in Hardy–Weinberg Equilibrium. In an association analysis, it was revealed that allele C was associated with variation in the mean fibre curvature of the fine wool of the Chinese Tan lambs, but this association was not observed in their heterotypic hair fibres. This finding suggests that KRTAP36-1 might be differentially expressed in the wool follicles that produce the two fibre types, and that along with other KRTAP genes, it may be involved in determining fibre curvature and the distinctive curly coat of the lambs. Full article

Keratin plays a crucial role in wool formation. Conducting polymorphism studies on key keratin genes is helpful in identifying key SNP sites that might influence wool traits. In this research, kompetitive allele-specific PCR (KASP) genotyping and protein immunofluorescence techniques were used to explore the polymorphisms of the KRT71 gene in Gansu alpine fine-wool sheep, analyze the relationship between the gene polymorphisms and wool production traits, and examine the expression and localization of the KRT71 protein in the hair follicles of fine-wool sheep. The results indicated that there were two single-nucleotide polymorphisms (SNPs) in the 5′ UTR and exon 9 of the KRT71 gene, named SNP1 (C.-7G/C) and SNP2 (C.1500G/A), respectively. Regarding SNP1, the mean stable length (MSL) of GG genotype individuals was significantly longer than that of GC genotype individuals (p < 0.05). Similarly, for SNP2, the MSL of GG genotype individuals was significantly greater than that of GA genotype individuals (p < 0.05). Moreover, the KRT71 protein showed moderate positive expression in the cuticle, outer root sheath, and sebaceous gland. It had strong positive expression in the inner root sheath, while no positive expression was detected in the hair medulla and hair papilla. In summary, the sheep KRT71 gene could be an important candidate gene for improvements in wool length. Full article

Dietary protein levels greatly influence gut microbial ecosystems; however, their effects on gut archaea and associated functions in ruminants require further elucidation. This study evaluated the impact of varying dietary protein levels on gut archaeal composition, antimicrobial resistance (AMR) genes, virulence factors, and functional capacities in sheep. Eighteen ewes (Yunnan semi-fine wool breed, uniparous, 2 years old, and averaging 50 ± 2 kg body weight) were randomly assigned to diets containing an 8.5 (low; H_1), 10.3 (medium; H_m), or 13.9% (high; H_h) crude protein level from the 35th day of pregnancy to the 90th day postpartum. The total duration of the experiment was approximately 202 days. A total of nine fecal samples (three from each group) were analyzed via 16S rRNA and metagenomics sequencing. Higher archaeal alpha diversity and richness were observed in the H_m and H_h groups compared to the H_l group (p < 0.05). A Beta diversity analysis revealed the archaeal community’s distinct clustering mode based on protein levels. The methanogenic genera Methanobrevibacter and Methanocorpusculum were dominant across the three groups, and their abundance was influenced by protein intake. A functional prediction analysis indicated moderate changes in amino acid and carbohydrate metabolism, which are particularly associated with methane production, an important source of greenhouse gases. AMR genes (e.g., tetA (60), patA, vat, and Erm methyltransferase) and virulence factors (Bacillibactin, LPS) were significantly enriched when animals were fed high-protein diets. Our results demonstrated that dietary protein levels significantly influence gut archaeal composition, AMR gene enrichment, and related functional pathways. Medium-protein diets promoted greater archaeal diversity, whereas high-protein diets favored resistance gene proliferation and enhanced methanogenic activity. Optimizing dietary protein intake may enhance gut health, mitigate antimicrobial resistance risk, and reduce methane emissions, thereby supporting livestock sustainability and environmental protection. Full article

Liangshan Semi-fine Wool Sheep (LSWS, Ovis aries) are widely raised in Liangshan Yi Autonomous Prefecture, Sichuan, China. To provide a scientific basis for LSWS meat processing, our study investigated various parameters across six meat parts of LSWS including the neck, chuck roll, thin flank, outside flat, eye of round, and hind shank. Our findings revealed that thin flank displayed a higher pH₂₄ compared to outside flat (p < 0.05), as well as greater lightness than outside flat and hind shank (p < 0.05), along with higher redness than eye of round (p < 0.05). Hardness among six meat parts ranked in descending order as chuck roll, hind shank, outside flat, eye of round, neck, and thin flank. Meanwhile, the odor activity value decreased in the order of thin flank, eye of round, hind shank, neck, chuck roll, and outside flat. In terms of the nutritional composition, hind shank exhibited the highest protein content (p < 0.05). Thin flank also contained elevated levels of polyunsaturated fatty acids (PUFAs, 4977 μg/g), Σn-3 (1859 μg/g) and Σn-6 (2962 μg/g) fatty acids (p < 0.05). Regarding human health implications, thin flank showed a lower thrombogenicity index (p < 0.05). This study undertook a comprehensive analysis of meat quality and nutritional attributes across six LSWS meat parts, providing a scientific foundation for LSWS meat industry development and assisting consumers in making informed purchasing decisions. Full article

With economic development and improved living standards, the demand for mutton and wool continues to grow, and improving the production performance and genetic potential of sheep breeds has become the key to promoting the high-quality development of the sheep industry. Thus, this study analyzes the influencing factors of the early production traits of Yunnan semi-fine wool sheep, optimizes the genetic evaluation model, and relies on accurate genetic parameter estimation to provide a theoretical basis for formulating a scientific and efficient breeding strategy for this breed. Data were collected from the Laishishan and Xiaohai breeding farms in Qiaojia, Yunnan, covering production records of the core flock from 2018 to 2022. Using the GLM procedure in SAS 9.4 software, this study analyzed the non-genetic influences on early production traits in Yunnan semi-fine wool sheep. Concurrently, Danish Milk Unit 5 (DMU 5) software estimated the variance components across various animal models for each trait. Employing the Akaike Information Criterion (AIC) and likelihood ratio test (LRT), six models were tested, incorporating or excluding maternal inheritance and environmental impacts, to identify the optimal model for deriving the genetic parameters. The results show that the birth year, dam age, sex, flock and litter size significantly affect both the Birth Weight (BWT) and Weaning Weight (WWT) (p < 0.01). Additionally, the birth month was found to exert a significant effect on Birth Weight (BWT) (p < 0.01), the weaning month has a significant effect on the Weaning Weight (WWT) (p < 0.05). No significant effects of farm location were observed on either trait (p > 0.05). The most accurate genetic evaluation model determined the heritability of the Birth Weight (BWT) and Weaning Weight (WWT) as 0.3123 and 0.3471. From a production perspective, improving lamb birth, Weaning Weight (WWT), feed composition, and maternal nutrition during gestation is vital for breeding efficiency. This study not only identified the optimal animal models for early growth traits in Yunnan semi-fine wool sheep, offering a precise basis for estimating genetic parameters but also provides theoretical guidance for genetic selection and breed improvement in this population. Full article

The proliferation and maturation of hair follicles in follicular papilla cells are predominantly governed by miRNAs, which significantly influence the cell cycle, apoptosis, and proliferation. miR-370-3p has been associated with several biological processes and targets SMAD4, a crucial component in hair follicle development. Tissue expression profiling revealed significant differences in miR-370-3p levels between skin tissues of the two sheep breeds in January and October, as well as between tissues of the Xinji fine-wool sheep and Small-tail Han sheep. SMAD4 exhibited significant differences in tissue-specific expression in the heart, spleen, skin, lungs, and muscles from Xinji fine-wool sheep and Small-tail Han sheep. Bioinformatics analysis and dual-luciferase reporter assays validated the regulatory interaction between miR-370-3p and SMAD4. CCK-8 experiments demonstrated that miR-370-3p’s targeting of SMAD4 suppressed cell growth. Cell cycle analysis demonstrated that miR-370-3p’s targeting of SMAD4 influenced the cell cycle. Annexin V-FITC/PI dual labeling demonstrated that miR-370-3p’s targeting of SMAD4 promoted cell apoptosis. RT-qPCR data demonstrated that miR-370-3p’s targeting of SMAD4 elevated the expression of JUN, c-MYC, and TCF7L2 while suppressing β-catenin expression. Western blot (WB) analysis demonstrated that miR-370-3p targeting of SMAD4 significantly promoted c-MYC expression while inhibiting CCND1, CCND2, and β-catenin expression. miR-370-3p and SMAD4 exhibit spatiotemporal expression differences in sheep skin tissues, with widespread expression across various tissues. Furthermore, it confirmed that miR-370-3p targets SMAD4 to inhibit follicular papilla cell proliferation, promote apoptosis, and influence the cell cycle. Full article

Understanding the genetic factors that influence wool quality is essential for enhancing wool quality and uniformity. This study investigated the KRTAP13-3 gene in Chinese Tan sheep, a breed known for its unique wool characteristics. We analysed 232 sheep and revealed five previously identified sequence variants of KRTAP13-3 and then modelled to ascertain whether there was any association between the nucleotide sequence variation and variation in mean fibre diameter (MFD), fibre diameter standard deviation (FDSD), coefficient of variation of fibre diameter (CVFD), and mean fibre curvature (MFC). Twelve genotypes were observed, with the five variants having frequencies that ranged from 64.0% to 1.1%. Among the four variants with frequencies above 5%, nucleotide sequence variation was associated with heterotypic hair fibre diameter variation. The most common variant (A) was linked to increased FDSD and CVFD, while two other variants (B and D) revealed trends towards being associated with decreased CVFD. No associations were found with variation in the fine wool fibres from the Tan sheep. This suggests that KRTAP13-3 plays a role in regulating heterotypic hair fibre diameter variability and that it could possibly be a gene marker for improving wool traits. Full article

Tail fat is essential for sheep survival in extreme environments, yet its significance is often overlooked, leading to the decline of fat-tailed breeds. This study identified a novel lncRNA, lncRSFD1 (TCONS_00054953), through transcriptome sequencing, showing differential expression in the tail adipose tissues of Lanzhou Fat-Tailed (LFT) sheep and Tibetan (TS) sheep. Highly expressed in adipose tissues, lncRSFD1 inhibits preadipocyte proliferation and promotes 3T3-L1 differentiation, suggesting its role in regulating fat deposition. Located in both the cytoplasm and nucleus, lncRSFD1 targets the neighboring gene PDE4DIP and may function as a molecular sponge for conserved miRNAs, including oar-miR-30a-3p, oar-miR-329b-5p, and oar-miR-431, which are known to influence fat and muscle-related physiological processes. Moreover, the core promoter of lncRSFD1 (−2607 bp to −1776 bp) harbors four SNPs (g.-2429G>A, g.-2030T>C, g.-2016C>T, g.-2015G>A) significantly associated with growth traits such as body height in Guiqian Semi-Fine Wool (GSFW) sheep. These findings suggest lncRSFD1 plays a key role in fat deposition and growth regulation, offering new insights into the molecular mechanisms of lncRNAs in sheep. It provides a potential target for genetic improvement and molecular breeding to enhance fat deposition and adaptability in sheep breeds. Full article

Sheep are a vital species in the global agricultural economy, providing essential resources such as meat, milk, and wool. Merino sheep (Junken type) are a key breed of fine wool sheep in China. However, research on fine wool traits has largely overlooked the role of SNPs and their association with phenotypes. Copy number variations (CNVs) have emerged as one of the most important sources of genetic variation, influencing phenotypic traits by altering gene expression and dosage. To generate a comprehensive CNVR map of the ovine genome, we conducted genome-wide CNV detection using genotyping data from 285 fine wool sheep. This analysis revealed 656 CNVRs, including 628 on autosomes and 28 on the X chromosome, covering a total of 43.9 Mbs of the sheep genome. The proportion of CNVRs varied across chromosomes, from 0.45% on chromosome 26 to 3.72% on chromosome 10. Functional annotation through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses highlighted significantly enriched GO terms, including odorant binding, ATP binding, and sulfuric ester hydrolase activity. The KEGG analysis identified involvement in pathways such as neuroactive ligand–receptor interaction, axon guidance, ECM–receptor interaction, the one-carbon pool by folate, and focal adhesion (p < 0.05). To validate these CNVRs, we performed quantitative real-time PCR experiments to verify copy number predictions made by PennCNV software (v1.0.5). Out of 11 selected CNVRs with predicted gain, loss, or gain–loss statuses, 8 (IDs 68, 156, 201, 284, 307, 352, 411, 601) were successfully confirmed. This study marks a significant step forward in mapping CNVs in the ovine genome and offers a valuable resource for future research on genetic variation in sheep. Full article