Yaojing Yue

Sertoli cells are essential for testicular development and spermatogenesis, but the post-transcriptional mechanisms regulating their function in sheep remain incompletely understood. This study investigated the regulatory relationship between miR-132-y and Yes-associated protein 1 (YAP1), a core effector of the Hippo pathway, in primary Sertoli cells isolated from Southdown × Hu F1 sheep. Target prediction and dual-luciferase reporter assays supported a direct interaction between miR-132-y and the YAP1 3′ untranslated region. YAP1 overexpression was associated with increased CCK-8-based cell viability and altered mRNA expression of selected viability-associated, YAP1-related, and Sertoli cell function-associated genes, whereas YAP1 silencing showed opposite trends. Conversely, miR-132-y overexpression reduced YAP1 mRNA abundance and was associated with decreased CCK-8-based cell viability and corresponding transcriptional changes, while miR-132-y inhibition produced the opposite pattern. Rescue experiments showed that ectopic YAP1 expression partially attenuated miR-132-y-associated changes. Overall, these findings provide in vitro, cell-based evidence that miR-132-y targets YAP1 at the transcript level and is associated with viability-related transcriptional responses in sheep Sertoli cells.

Objective: To dissect host transcriptional reprogramming in naturally SPA‑infected sheep lungs via whole‑transcriptome sequencing and identify core regulatory factors in JSRV‑induced oncogenesis.Methods: Whole‑transcriptome sequencing was performed on SPA and healthy lung tissues to profile mRNAs, lncRNAs, miRNAs, and circRNAs. Differential expression, functional enrichment, and ceRNA network analyses were conducted, followed by RT‑qPCR validation.Results: We identified 2,067 DE‑mRNAs, 72 DE‑lncRNAs, 210 DE‑miRNAs, and 477 DE‑circRNAs. Enriched pathways included MAPK, PI3K–Akt, mTOR, and Hippo. A ceRNA network revealed key axes: novel_circ_008415–oar‑miR‑16b–ALDH1A2, MSTRG.36927.2–oar‑miR‑16b–CD22, and MSTRG.36932.1–oar‑miR‑16b–BCL2/CCND1.Conclusion: This study provides a comprehensive whole‑transcriptome landscape of naturally SPA‑infected sheep lungs, uncovering ceRNA‑mediated regulation of tumor apoptosis, immune evasion, and proliferation, offering insights into JSRV‑induced oncogenesis and potential biomarkers.

With the increasing consumer demand for high-quality lamb, crossbreeding has become a key technology for improving the production performance and meat quality of sheep. To evaluate the meat quality advantages and characteristics of Suffolk (SFK) and Hu sheep (HH) and their F₁ crossbreds (SH), thirty-six 3-month-old male lambs of SFK (n = 12), HH (n = 12), and SH (n = 12) were selected and raised in individual pens under the same nutritional and management conditions. After standardized feeding until 6 months of age, the Longissimus dorsi muscle was collected to determine meat quality traits, amino acid and fatty acid profiles, and volatile flavor compounds. The results indicated that the L*, a* and b* values of the SH group were significantly lower than those of the parental breeds (p < 0.05), with tenderness being intermediate between the two parent breeds. Notably, drip loss and cooking loss were significantly lower in the SH group (p < 0.05), indicating superior water-holding capacity. In terms of amino acid profiles, the contents of non-essential amino acids (NEAAs) and sweet-tasting amino acids in the SH group were significantly higher than those of the parent breeds (p < 0.05), with the overall profile meeting the FAO/WHO ideal protein pattern. Analysis of fatty acid profiles revealed that the SH group had significantly lower total saturated fatty acids (SFAs) (p < 0.05) and significantly higher levels of functional fatty acids (such as CLA), resulting in a significantly higher UFAs (unsaturated fatty acids)/SFAs (saturated fatty acids) ratio (p < 0.05) and superior nutritional value of fat. Furthermore, 32 volatile flavor compounds were detected in the SH group; among them, key aroma-active compounds such as isoamyl formate, 3-methyl-1-butanol, and acetoin were significantly higher than in the parental breeds (p < 0.05), contributing to a unique flavor profile. Consequently, this study systematically reveals the advantages of Suffolk × Hu F₁ crossbreds in terms of meat quality, nutritional value, and flavor characteristics, providing fundamental data for the optimization of crossbreeding systems, breeding selection, and the quality improvement of sheep meat products.

Objective: Although Hu sheep are renowned for their high fecundity, the multi-tissue regulatory networks governing spermatogenesis, particularly within the hypothalamic–pituitary–testicular (HPT) axis, remain poorly understood. This study aimed to elucidate these mechanisms by performing a comparative proteomic analysis of the HPT axis in Hu sheep and three other breeds. Methods: We utilized data-independent acquisition (DIA) proteomics to analyze hypothalamic, pituitary, and testis tissues from 36 samples across four breeds. The experimental workflow included protein extraction, enzymatic digestion, LC-MS/MS, and subsequent bioinformatic analyses, complemented by histological examination. Results: Hu sheep exhibited accelerated testicular development and an earlier onset of spermatogenesis. Comprehensive proteomic profiling identified a total of 10,528 proteins, with 771 differentially expressed proteins (DEPs) detected in the testis. These testicular DEPs were significantly enriched in pathways related to spermatogenesis, the blood–testis barrier, and steroid hormone biosynthesis. Notably, the cAMP signaling pathway was consistently enriched across all three tissues, underscoring its pivotal role in regulating spermatogenesis. Protein–protein interaction (PPI) network analysis further highlighted hub proteins, such as MET, suggesting their potential involvement in somatic cell functions and the spermatogenic microenvironment. Key findings were validated by Western blot analysis. Conclusion: This study is the first multi-tissue proteomic investigation proposing a model in which the high reproductive performance of Hu sheep is potentially linked to the efficient, coordinated regulation of spermatogenesis-related proteins and signaling pathways—particularly in the testis. These findings offer novel insights into the molecular mechanisms of male reproduction in sheep and identify potential targets for future research and breeding applications.

This study was conducted to investigate potential regulatory mechanisms of hybridization increased the meat production performance in sheep. Thirty-six 3-month-old male lambs of Suffolk sheep (SFK, n = 12), Hu sheep (HH, n = 12), and their F₁ hybrids (SH, n = 12) were selected and raised in individual pens under identical nutritional supply and husbandry management regimes over a 95-day (including a 15-day pre-trial period) experimental period. At the end of the feeding trial, six sheep closest to the average body weight were selected from each group for the subsequent trial, involving the collection of Longissimus dorsi samples and the determination of production performance, muscle fiber characteristic and transcriptomic and metabolomic analysis. The results showed that the SH sheep had significantly higher pre-slaughter live weight and carcass weight than the HH sheep, while lower than those of the SFK sheep (p < 0.05). The muscle fiber density of the SH group was significantly higher than that of the parental groups, while the muscle fiber diameter and cross-sectional area were significantly smaller (p < 0.05). The collagen fiber content of the SH group was intermediate between the two parental groups and significantly higher than that of the SFK group (p < 0.05). Transcriptomic analysis identified 2920 differentially expressed genes (DEGs), which were mainly enriched in the AMPK, PI3K-Akt, and PPAR signaling pathways. Metabolomic analysis detected 1617 differential metabolites (DMs), which were enriched in the fatty acid degradation and steroid hormone biosynthesis pathways. Integrated analysis revealed that core genes SESN3 and metabolites (malate, testosterone) enhance energy supply capacity through AMPK pathway, thereby promoting muscle fiber proliferation and increasing meat yield in the hybrid sheep. In conclusion, the heterosis of the SH group originates from the remodeling of muscle fiber structure and the synergistic regulation of related pathways, which provides a theoretical basis for sheep crossbreeding.

Accurate EMA assessment in live sheep is crucial for genetic breeding and production management within the meat sheep industry. However, the segmentation accuracy and reliability of existing automated methods are limited by challenges inherent to B-mode ultrasound images, such as low contrast and noise interference. To address these challenges, we present MPG-SwinUMamba, a novel deep learning-based segmentation network. This model uniquely combines the state-space model with a U-Net architecture. It also integrates an edge-enhancement multi-scale attention module (MSEE) and a pyramid attention refinement module (PARM) to improve the detection of indistinct boundaries and better capture global context. The global context aggregation decoder (GCAD) is employed to precisely reconstruct the segmentation mask, enabling automated measurement of the EMA. Compared to 12 other leading segmentation models, MPG-SwinUMamba achieved superior performance, with an intersection-over-union of 91.62% and a Dice similarity coefficient of 95.54%. Additionally, automated measurements show excellent agreement with expert manual assessments (correlation coefficient r = 0.9637), with a mean absolute percentage error of only 4.05%. This method offers non-invasive and efficient and objective evaluation of carcass performance in live sheep, with the potential to reduce measurement costs and enhance breeding efficiency.

The epididymis is a crucial organ for sperm maturation and storage, with metabolic microenvironmental differences across its functional segments (Caput, Corpus, Cauda) being pivotal to this process. However, the underlying metabolic regulatory mechanisms remain incompletely defined. This study systematically characterized region-specific metabolic profiles in the epididymis of Hu sheep and elucidated their functional associations with sperm maturation. Tissues from the caput, corpus, and cauda of the epididymis from eight Hu rams were subjected to untargeted metabolomic analysis using UHPLC-Q-Exactive HF-X. Differential metabolites were screened by combining multivariate statistical analysis (OPLS-DA, VIP >1) and univariate statistical analysis (student t -test, p < 0.05), with key metabolic networks identified through KEGG pathway enrichment. We detected 3,393 metabolites, including 1,844 differentially abundant metabolites: 1,038 between the caput and corpus, 1,243 between the cauda and caput, and 1,159 between the cauda and corpus. KEGG analysis revealed significant enrichment in biosynthesis pathways, cAMP signaling, and protein digestion/absorption. Our findings demonstrate that compartmentalized metabolic reprogramming—particularly involving choline and L-carnitine—drives sperm maturation, providing critical targets for optimizing semen cryopreservation technologies in Hu sheep.

Fecundity limits sheep industry development, but crossbreeding can help. Yet, mechanisms of testis development in Southdown × Hu F1, especially differential mechanisms at key stages, are rarely studied. Recent miRNA-mRNA analyses have enhanced our understanding of testicular sexual development stages. We conducted histological, physiological, and transcriptomic analyses on neonatal (M0) and adult (Y1) testis tis-sues of Southdown × Hu F1. Results showed Y1 testes were fully developed with more germ cells than M0. miRNA-seq identified 405 differentially expressed miRNAs (DEMIs) (43 existing, 212 known from 175 families, and 150 novel), and mRNA-seq found 9794 differentially expressed mRNAs (DEMs). miRNA-mRNA integration analysis yielded 20 miRNA-target gene pairs (20 DEMIs and 145 DEMs). Key pathways like Rap1 signaling, ECM-receptor interaction, and MAPK were identified. miR-29a, miR-544-z, and miR-128-z were found to regulate ITGB1, MAP3K13, and Rap1 respectively, along with key genes KITLG, GATA4, and CDC42 in testicular development, affecting male reproduction. This study clarifies testicular development mechanisms and offers candidate genes for molecular breeding.