畜產試驗所

Abstract Napier grass ( Cenchrus purpureus syn. Pennisetum purpureum ), a perennial C 4 forage and bioenergy crop, exhibits strong drought resilience, yet the integrative mechanisms underlying this tolerance remain incompletely understood. This study examined physiological, hydraulic, and metabolic responses of four Napier grass cultivars under PEG-induced osmotic stress and progressive soil water deficit. Drought significantly increased the root-to-shoot ratio, indicating preferential biomass allocation to roots, which supported maintenance of shoot growth and tissue water status. All cultivars showed an approximate twofold increase in water-use efficiency (WUE) under water deficit, with cv2 and cv7 displaying superior performance. Upregulation of aquaporin genes ( PIP2;2 and PIP2;3 ) suggested active hydraulic regulation that sustained carbon assimilation under reduced transpiration. Metabolic profiling revealed pronounced root-centered osmotic adjustment, including accumulation of galactinol, myo-inositol, raffinose family oligosaccharides, proline, and several amino acids. Enhanced expression of the galactinol synthase gene confirmed activation of raffinose biosynthesis pathways. Genotypic variation highlighted cv2 as particularly drought resilient. Rapid post-stress regrowth further underscored the importance of perennial root persistence. In conclusion, drought tolerance in Napier grass arises from coordinated hydraulic resilience, osmotic adjustment, and C 4 photosynthetic efficiency, supporting its suitability for forage and bioenergy production in water-limited environments. Significant This study shows drought tolerance in Napier grass relies on root-driven hydraulic and metabolic regulation with efficient water-use efficiency, rather than avoidance, and that PEG responses predict field performance.

This study investigated whether maternal origin affects boar semen thermotolerance and its seasonal reproductive performance. Crossbred boars with different maternal origins were evaluated (K and KD boars with Meishan-derived cytoplasm and DK boars with Duroc-derived cytoplasm). Heat stress treatment (42 and 39 °C) on semen samples significantly reduced sperm viability and acrosome/membrane integrity while increasing mitochondrial damage. Notably, the decline in semen quality under heat stress was significantly lower (p < 0.05) in K and KD boars than in DK boars. The farrowing rates during the hot season were significantly higher (p < 0.05) in the K and KD breed compared with the DK breed. No significant differences among groups were observed during the cool season. Collectively, these findings indicate that maternal origin may contribute to mitochondrial stability and semen resilience under tropical heat stress, thereby influencing reproductive performance in hot seasons. Maternal inheritance should therefore be considered in breeding strategies of improving heat tolerance in pigs.

Background and Aim:Uterine receptivity is critical for successful embryo implantation, yet epithelial-specific proteomic changes during this transition remain incompletely characterized. This study aimed to profile changes in protein expression in isolated mouse endometrial epithelial cells between the pre-receptive (Day 1) and receptive (Day 4) phases of pregnancy to identify key pathways associated with uterine receptivity. Materials and Methods:Endometrial epithelial cells were isolated from pregnant CD-1 mice on Days 1 and 4 of pregnancy. Protein extracts were analyzed using two-dimensional gel electrophoresis followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for identification. Differentially expressed proteins were functionally annotated using Gene Ontology. Key candidates, including Gstm2 and vimentin, were validated by immunofluorescence and quantitative real-time polymerase chain reaction. Results:Approximately 674 protein spots were detected, of which 80 were differentially expressed (p < 0.05, ≥2-fold change) and 52 were successfully identified. These proteins were primarily associated with cellular metabolism, redox regulation, protein folding, and endoplasmic reticulum (ER) stress responses. Coordinated upregulation of antioxidant proteins (Gstm2, Gstm7, Prdx2, Cat) and ER stress-associated proteins (PDIA3, HSPA5) was observed on Day 4. Gstm2 showed consistent upregulation at both protein and transcript levels (p < 0.05) with enhanced epithelial localization, while vimentin expression remained stable, supporting cytoskeletal readiness. These changes indicate integrated redox homeostasis and stress adaptation during the acquisition of uterine receptivity. Conclusion:This epithelial-specific proteomic analysis reveals coordinated redox and ER stress-associated pathways during the transition to uterine receptivity in mice. The findings provide a focused proteome resource that highlights Gstm2 as a candidate regulator within antioxidant networks and establishes a foundation for understanding molecular mechanisms at the embryo-maternal interface.

Large full-thickness (LFT) skin wounds remain a major clinical challenge, and progress in regenerative medicine has been limited by poor translation from animal models to humans. A key limitation is that commonly used species such as mice, rats, and rabbits are loose-skinned, whereas humans are tight-skinned with distinct skin architecture. Although pigs more closely resemble human skin, widely used breeds have lost secondary (vellus-like) hair follicles through artificial selection, restricting their utility for studying ectodermal organ regeneration. Here, we characterize the development, patterning, and molecular features of secondary hair follicles in the Lanyu pig (Sus scrofa taivanus), an indigenous breed that retains these structures. Whole-mount and histological analyses revealed two distinct follicle populations: primary follicles arranged in stable triplet clusters and smaller secondary follicles distributed interstitially. A developmental time course using alkaline phosphatase (ALP) staining identified sequential stages of secondary follicle morphogenesis—placode, hair germ, hair peg, and mature follicle—occurring after primary follicle establishment. Immunohistochemical analysis demonstrated conserved epithelial–mesenchymal interactions, progressive epithelial stratification, and dynamic β-catenin signaling during secondary follicle development. Keratin expression patterns and follicular architecture closely resembled those of human vellus hair follicles, supporting the translational relevance of this model. Notably, secondary follicles were retained into adulthood, and genetic analyses of outcrossed animals suggest that this trait follows an autosomal dominant inheritance pattern. Together, these findings establish the Lanyu pig as a tight-skinned mammalian model that preserves vellus-like hair follicles, providing a platform for investigating hair follicle–mediated skin regeneration and improving translational relevance for human wound healing.

Dry aging enhances meat quality, yet the interplay between microbial communities and metabolite composition remains insufficiently understood. To address this, we investigated the microbial and metabolomic shifts during low-temperature dry aging of black pig loins to identify key drivers of flavor development. Black pig loins were aged at 2 ± 1 °C temperature and 75 ± 10% humidity for 4 weeks. After the aging process, increased meat elasticity and free amino acid content were associated with significant improvements in quality. Integrated microbial and metabolomic analysis revealed a strong positive correlation between Debaryomyces abundance and key flavor-active metabolites, specifically those derived from amino acid metabolism. This pinpointed Debaryomyces as a primary metabolic driver. To validate these functions, Debaryomyces hansenii strains OFMDh-412 and OFMDh-413, isolated from naturally dry-aged pork, were used as starter cultures. This targeted intervention significantly enhanced flavor development, increased total free amino acid content, and confirmed the role of these strains in flavor formation. In conclusion, this study provided evidence that the targeted application of D. hansenii demonstrated potential as a starter culture for dry-aged pork, enhancing flavor development and meat quality. These findings highlight the significance of microbe-metabolite interactions in flavor development and support the development of innovative dry-aging strategies to produce high-value meat products.