Animal Research and One Health最新文献

Conditional gene regulation systems can control gene expression in predefined tissues or organs at a desired time. Site-specific recombinase systems and chemically induced gene expression systems are the two most widely used approaches for creating genetically modified (GM) animals with conditional regulation of gene expression. Generation of GM pigs with controllable elements, usually involving multiple gene editing, used to be a major challenge due to a lack of germ line-competent pluripotent stem cells. With the emergence of artificial endonuclease-mediated gene editors, a variety of GM pigs with recombinase-specific recognition elements or chemically induced elements for conditional regulation of gene expression have been generated by the combination of site-directed knock-in of somatic cells and somatic cell nuclear transfer technology, allowing conditional deletion of endogenous genes or overexpression of exogenous genes in pigs. These inducible tool pig models will greatly facilitate the production of GM pigs and broaden the applications of transgenic pigs in biomedicine and agriculture fields. In this paper, we review the progress in the construction and application of pigs with controllable elements using gene editing techniques.

Reserve mesenchyme cells (RMCs) of deer antlers have been considered as the promising cell source for repairing injury-induced articular cartilage or cartilage degeneration. However, systematic investigation of RMC differentiation to repair injured cartilage and its combination with biomaterials has not been reported. The aim of this study was to evaluate the role of RMCs in combination with hyaluronic acid (HA) in promoting chondrogenic differentiation through simulating native environments and their efficacy in articular cartilage repair. The RMCs were cultured in vitro for the characterization of these cells, including morphology, surface marker expression, and multipotent differentiation potential (adipogenesis, chondrogenesis, and osteogenesis). When combined with HA in vitro, RMCs increased expression levels of the chondrogenic marker gene (COL II and COMP) but decreased levels of the hypertrophic marker gene (COL X). Using a rat articular cartilage defect model, we evaluated the effects of RMCs in combination with HA on cartilage defect repair at 4 and 8 weeks through macroscopical, histological, and immunohistochemical examinations. Compared with other groups, treatment with RMCs + HA reduced cartilage loss and degree of cartilage surface worn, whereas cartilage content was significantly increased. These results suggest that the combination of RMCs with HA can effectively repair cartilage defects. We believe that effective cartilage defect repair will benefit from the use of RMCs together with favorable biomaterials, such as HA.

A range of studies indicates that keeping farm animals in crowded, stressful conditions leads to an increased risk of the emergence, transmission, and amplification of pathogens including zoonoses. Some such zoonoses could lead to a pandemic. Biosecurity, though essential, is not on its own sufficient to prevent the entry of disease into large, intensive livestock housing. To minimize disease risks, both biosecurity measures and the keeping of animals in conditions that are supportive of good health and effective immunocompetence are necessary. A further threat to human health arises from the routine use of antimicrobials in intensive livestock production to prevent disease. This high use of antimicrobials contributes significantly to the emergence of antimicrobial resistance in animals, which can then be transferred to people, thereby undermining the efficacy of the antimicrobials that are so important in human medicine. If we want to save our antimicrobials and minimize the risk of future zoonoses and pandemics, we need to move to “health-oriented systems” for the rearing of animals, systems in which good health is inherent in the farming methods rather than being dependent on the routine use of antimicrobials. Health-oriented systems should avoid high stocking densities and large group size, should minimize stress and mixing of animals, and ensure that animals can perform their natural behaviors as the inability to do so is highly stressful. They should avoid the use of animals selected for excessive production levels as these appear to involve an increased risk of immunological problems and pathologies.

Animal welfare closely depends on its ability to adapt and thrive in a harmonious relationship with its environment, ensuring both physical and psychological well-being. Over the years, the welfare of farm animals has gathered global attention and has become increasingly important to the general public and scientific communities. The connection between the environment and animal welfare is primarily established through the provision of suitable and controllable environment for animals. However, it is essential to recognize that the impact of environment extends beyond merely ensuring freedom from discomfort. The environment plays a crucial role in shaping an animal's response to challenges such as disease, stress, and pathogen. While animals may be housed in controlled environments that provide optimal conditions for health, production, and welfare, it is important to acknowledge that specific scenarios can significantly affect and alter the environmental requirements. Even with access to fresh air, certain factors can have a substantial impact on the well-being of animals. Furthermore, providing appropriate environmental conditions goes beyond meeting basic needs and can greatly contribute to allowing animals to engage in their natural behaviors. It serves as a relevant tool for ensuring and maintaining adequate welfare standards. This review takes a comprehensive approach to environmental welfare by considering the welfare of animals managed in different stocking systems, considering environmental stress, stocking systems, and the provision of environmental enrichment items. By examining these factors, a broader understanding of the relationship between environment and welfare is achieved and recommendations for future research are outlined.

Milk serves two nutritional functions: it provides nutrition while also maintaining a healthy intestinal microenvironment. Thus, the safety and quality of milk products are critical for consumers' health. To evaluate liquid milk and infant formula products in China, we analyzed nine indices of 294 batches of pasteurized milk (PM), 92 batches of ultra-high temperature milk (UHT), and 20 batches of infant formula milk powder (IF) collected from 21 provinces in 2022. All PM, UHT, and IF samples were satisfactory concerning aflatoxin M₁ contamination, contamination by heavy metals, and residues of veterinary drugs and pesticides. The contents of lactoferrin, α-lactalbumin, β-lactoglobulin, furosine, and lactulose in the majority of samples met the group standards. Moreover, the contents of lactoferrin, α-lactalbumin, and β-lactoglobulin were higher in PM than in UHT, while furosine and lactulose contents showed the opposite trend. The findings concerning the safety and quality of milk products in China provide important insights to aid consumer preferences for milk products.

Multiple trait genomic selection incorporating correlated traits can improve the predictive ability of low-heritability traits. In this study, we evaluated genomic prediction accuracy using multi-trait BayesCπ method (MT-BayesCπ), which allows for a broader range of mixture priors for important traits in beef cattle. We compared the prediction performance of MT-BayesCπ with single-trait genomic best linear unbiased prediction (ST-GBLUP), multi-trait GBLUP (MT-GBLUP), and single-trait BayeCπ (ST-BayesCπ) methods. We found that ribeye area (REA) and ribeye weight (REWT) showed high heritability, while slaughter weight (SWT) and carcass weight (CWT) displayed medium heritability, and slaughter rate (SR) and feedlot average daily gain (FDG) showed low heritability. Highly positive genetic correlations were observed between CWT and SWT (0.981) and SR and REWT (0.921). Notably, the MT-BayesCπ method showed superior predictive abilities compared to other models. Using MT-BayesCπ method, the accuracy increased from 0.272 to 0.694 for CWT compared to ST-GBLUP and ST-BayesCπ. MT-GBLUP and ST-BayesCπ showed similar prediction accuracies, while MT-BayesCπ showed the least biased evaluations. Additionally, our results suggested that prediction accuracy of low-heritability traits significantly increased when they were combined with traits with high genetic correlation in a multi-trait prediction. Our study suggests that multi-trait genomic predictions using GBLUP and Bayesian mixture prior models is feasible for genomic selection in beef cattle. Our findings indicate that MT-BayesCπ outperforms other models (ST-GBLUP, MT-GBLUP and ST-BayesCπ), especially for low-heritability traits.

Supplementation of diets with a modest amount of zinc methionine (ZM) has been documented to improve the growth performance and antioxidant function of dairy calves, but the underlying mechanisms remain elusive. In the present study, 16 dairy calves were allocated to a control (CON) group (calves consumed a basal diet) and a ZM group (calves ingested the basal diet and had an additional 455 mg ZM/day, corresponding to 80 mg zinc/day). The calves were fed these diets for 2 weeks, after which their serum antioxidant parameters, lipids, and jejunal mucosal proteome and microbiota were analyzed. The ZM group had lower levels of total cholesterol, triglycerides, and malondialdehyde but higher high-density lipoprotein cholesterol and glutathione peroxidase activity in the serum. A total of 142 differentially expressed proteins in the intestinal mucosa between the CON and ZM groups had been identified (ZM upregulated 117 proteins and downregulated 25 proteins). In addition, the protein expression of acyl-coenzyme A oxidase 1, fatty acid binding protein 2, and peroxisome proliferator-activated receptor gamma was higher in the ZM group. 16S rRNA gene sequencing indicated beneficial microbes, such as Veillonellaceae, Akkermansia_muciniphila, and Bifidobacterium adolescentis, which were more abundant, whereas Acinetobacter lwoffii was less abundant in calf jejunal mucosa in the ZM group. Finally, the propionate, butyrate, and iso-valerate concentrations in the jejunal digesta were greater in the ZM group than those in the CON group. Collectively, the present study shows that ZM supplementation improves the serum and intestine mucosal lipid metabolism associated with the alterations in mucosal fatty acids β-oxidation and microbiota.

As a typical psychrophilic bacterial pathogen, Aeromonas salmonicida causes furunculosis in wild and farmed freshwater and marine fish, leading to substantial economic losses in the global aquaculture industry. Previous studies have shown that A. salmonicida is unable to grow above 25°C, hence limiting its infection to cold-water fish. However, we isolated A. salmonicida SRW-OG1, a mesophilic pathogenic strain from the warm-water fish Epinephelus coioides. Through RNA-seq analysis, we observe significant upregulation of the zupT gene at 28°C. ZupT is a member of zinc-regulated transporters and iron-regulated transporter-like proteins (ZIP family) and is closely associated with transcriptional regulation of virulence in certain pathogens. Consequently, our study aimed to examine the role of zupT during A. salmonicida SRW-OG1 infection at high temperatures. Our findings demonstrate that the zupT-RNAi strain exhibits severe growth restriction under limited Zn²⁺ and Fe²⁺ conditions. Notably, this strain shows significantly reduced mortality rates and colonization abilities. Moreover, its motility, biofilm formation, adhesion, and hemolytic activities are significantly diminished. Confocal laser scanning microscopy reveals earlier and accelerated biofilm dissociation in the zupT-RNAi strain. Analysis of extracellular products at 36 h indicates a considerable reduction in relative extracellular protein content in the zupT-RNAi strain. Taken together, our results highlight the vital role of the zupT gene in zinc transport and the fitness of A. salmonicida SRW-OG1 within the host.

Proliferation of granular cells (GCs) plays an important role in ovary development, providing energy and a microenvironment for oocyte ovulation. In this study, we explored the spatiotemporal expression of SEMA4G and its effects on the growth and development of goat GCs using primary GCs cultured in vitro as a model. The results showed that the expression level of SEMA4G was significantly higher in the ovaries of high-fertility goats than in those of low-fertility goats (p < 0.05). The mRNA and protein expression levels of the cell proliferation markers of GCs were significantly increased after the overexpression of SEMA4G in goat primary GCs. The EdU and CCK8 results showed that cell viability was elevated in goat GCs and that proliferation was promoted by an increase in the number of proliferating cells. The proliferation of goat GCs was significantly inhibited by SEMA4G inhibition (p < 0.05). The results of online miRNA and target gene prediction software and dual luciferase activity analysis confirmed that SEMA4G could bind to mi-363-5p and was one of its target genes. The RT‒qPCR results showed that the expression level of miR-363-5p was significantly lower in the ovaries of high-fertility goats than in those of low-fertility goats in contrast to the expression level of SEMA4G (p < 0.05). After the overexpression of miR-363-5p in goat GCs, the expression of SEMA4G was significantly suppressed (p < 0.05). Collectively, the results of this study could lay the foundation for exploring the molecular mechanisms by which SEMA4G and miR-363-5p regulate the growth and development of goat GCs and provide targets for breeding high-fertility goats.

Exploring the genetic loci underlying economic traits is foundational for innovation in modern animal breeding technology. Genome-wide association studies (GWAS) have been valid and commonly used tools to dissect the genomic variants associated with phenotypes for the past ∼20 years and have contributed to our understanding of genetic and molecular bases of various traits. Here, we comprehensively review the recent research progress on GWAS methods. We highlight the methodological advancements enabled by the combination of new proteome, transcriptome, epigenome, and metagenome information and multi-omics analysis algorithms. The advances in GWAS investigations of chickens, pigs, cattle, and other animals during the last 5 years are also described. Finally, we discuss the current applications of GWAS in cutting-edge breeding technologies and overall future perspectives of the post-GWAS era.