The Min pig (Sus scrofa) is a well-known indigenous breed in China. One of its main advantages over European breeds is its high meat quality. Additionally, different cuts of pig also show some different traits of meat quality. To explore the underlying mechanism responsible for the differences of meat quality between different breeds or cuts, the longissimus dorsi muscle (LM) and the biceps femoris muscle (BF) from Min and Large White pigs were investigated using transcriptome analysis. The gene expression profiling identified 1371 differentially expressed genes (DEGs) between LM muscles from Min and Large White pigs, and 114 DEGs between LM and BF muscles from the same Min pigs. Gene Ontology (GO) enrichment of biological functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the gene products were mainly involved in the IRS1/Akt/FoxO1 signaling pathway, adenosine 5′-monophosphate-activated protein kinase (AMPK) cascade effects, lipid metabolism and amino acid metabolism pathway. Such pathways contributed to fatty acid metabolism, intramuscular fat deposition, and skeletal muscle growth in Min pig. These results give an insight into the mechanisms underlying the formation of skeletal muscle and provide candidate genes for improving meat quality. It will contribute to improving meat quality of pigs through molecular breeding.

The porcine epidemic diarrhea virus, PEDV, which causes diarrhea, vomiting and death in piglets, causes huge economic losses. Therefore, understanding how to induce mucosal immune responses in piglets is essential in the mechanism and application against PEDV infection with mucosal immunity. A method of treatment in our research was used to make an oral vaccine that packaged the inactive PEDV with microencapsulation, which consisted of sodium alginate and chitosan, and adapted the condition of the gut in mice. The in vitro release experiment of microcapsules showed that inactive PEDV was not only easily released in saline and acid solutions but also had an excellent storage tolerance, and was suitable for use as an oral vaccine. Interestingly, both experimental groups with different doses of inactive virus enhanced the secretion of specific antibodies in the serum and intestinal mucus, which caused the effective neutralization against PEDV in the Vero cell by both IgG and IgA, respectively. Moreover, the microencapsulation could stimulate the differentiation of CD11b+ and CD11c+ dendritic cells, which means that the microencapsulation was also identified as an oral adjuvant to help phagocytosis of dendritic cells in mice. Flow cytometry revealed that the B220⁺ and CD23⁺ of the B cells could significantly increase antibody production with the stimulation from the antigens’ PEDV groups, and the microencapsulation could also increase the cell viability of B cells, stimulating the secretion of antibodies such as IgG and IgA in mice. In addition, the microencapsulation promoted the expression of anti-inflammatory cytokines, such as IL-10 and TGF-β. Moreover, proinflammatory cytokines, such as IL-1, TNF-α, and IL-17, were inhibited by alginate and chitosan in the microencapsulation groups compared with the inactivated PEDV group. Taken together, our results demonstrate that the microparticle could play the role of mucosal adjuvant, and release inactivated PEDV in the gut, which can effectively stimulate mucosal and systemic immune responses in mice.

Soil physicochemical properties affect crop growth and yield. The addition of fertilizers can improve the soil quality during crop cultivation, leading to increased agricultural production. Organic fertilizers may be produced by composting straw that would otherwise be discarded as agricultural waste, with potential implications for sustainable agricultural development. However, the mechanism underlying the effects of straw compost on crop growth is unknown. In this study, a microbial agent suitable for straw decomposition in cold regions was used for a large-scale biological fermentation. Organic compost was obtained after the decomposition of straw. The straw compost was mixed with soil in different proportions and then used to cultivate Songjing 2 rice plants. The addition of straw compost significantly increased the growth and yield of the rice plants and enhanced various physiological indices. Moreover, the straw compost treatment significantly improved soil physicochemical properties (e.g., pH, enzyme activity, nutrient composition, and microbial diversity) and optimized the soil conditions for crop growth. In addition, the application of straw compost influenced the expression of genes in rice metabolic pathways as well as pathways mediating secondary metabolite synthesis and plant hormone signal transduction. The study data reflect the potential applicability of low-temperature straw fermentation technology for maximizing crop production.

Lactobacillus casei (L. casei) has four possible mechanisms: antimicrobial antagonism, competitional adhesion, immunoregulation, and the inhibition of bacterial toxins. To delineate the metabolic reactions of nucleotides from L. casei that are associated with mechanisms of inhibiting pathogens and immunoregulation, we report that a PyrR-deficient L. casei strain was constructed using the CRISPR-Cas9^D10A tool. Furthermore, there were some changes in its basic biological characterization, such as its growth curve, auxotroph, and morphological damage. The metabolic profiles of the supernatant between the PyrR-deficient and wild strains revealed the regulation of the synthesis of genetic material and of certain targeting pathways and metabolites. In addition, the characteristics of the PyrR-deficient strain were significantly altered as it lost the ability to inhibit the growth of pathogens. Moreover, we identified PyrR-regulating pyrimidine biosynthesis, which further improved its internalization and colocalization with macrophages. Evidence shows that the PyrR gene is a key active component in L. casei supernatants for the regulation of pyrimidine biosynthesis against a wide range of pathogens.

In recent years, outbreaks of Seneca Valley virus (SVV) in pig farms have raised concerns about disease resistance in different pig breeds. Min pigs are an excellent local pig breed in China, but the breed’s strong disease resistance mechanism has not been clearly investigated. In this study, Min pigs and Landrace pigs were challenged with SVV, and the differences in pathogenicity between SVV-infected Min and Landrace pigs were evaluated in terms of production performance, survival rate, immune cell activity, pathological changes, viral titer, and cytokine expression. The results show that the mortality rate in Min pigs was significantly lower than that in Landrace pigs without substantial weight loss. The copy number of SVV RNA in the intestinal mucosa of Min pigs was lower than that in Landrace pigs. Additionally, the IgA and IgG titers in Min pigs were higher than those in Landrace pigs. Both the absolute number and percentage of M1 macrophages were elevated in Min pigs relative to Landrace pigs. This study is the first to identify differences in macrophage activity between SVV-infected Min pigs and Landrace pigs. The presented results indicate the potential research value of studying innate immunity differences in disease resistance between pig breeds.

Serine is crucial for maintaining proper immune system function in both humans and animals. This study aimed to investigate the effects of dietary serine supplementation on microbial interactions and intestinal immunity in weaned piglets. In Exp. 1, a total of 35 weaned piglets (age 21 d, initial body weight [BW] 7.01 ± 0.07 kg, n = 7) were allocated to five dietary treatments for 42 d, a basal diet with no serine and supplemented with 0.25%, 0.50%, 0.75%, or 1.00% serine. The results showed that supplementation with 1.00% serine in the diet increased final BW and significantly elevated serum concentrations of immunoglobulin (Ig) A, IgG, and IgM (P < 0.05), supporting its selection for subsequent experiments. In Exp. 2, a total of 21 weaned piglets (age 21 d, initial BW 7.09 ± 0.09 kg, n = 7) were divided into three groups and fed for 28 d: basal diet (Ctrl), basal diet with D-galactose (D-Gal), and basal diet with 1.00% serine and D-galactose (Ser). D-galactose treatment significantly reduced average daily feed intake and aggravated intestinal morphological damage (P < 0.05), whereas serine supplementation effectively alleviated these effects (P < 0.05). Serine also enhanced systemic humoral immunity by increasing serum IgG and IgM on d 14 (P < 0.001) and serum IgA on d 28 (P = 0.003), and improved intestinal barrier function as evidenced by higher villus height to crypt depth ratios in the jejunum (P = 0.041) and ileum (P = 0.033). Furthermore, serine supplementation significantly downregulated the ileal mRNA expression of autophagy markers (becline, microtubule associated protein 1 light chain 3 beta [Lc3b-1], enhancer of polycomb 2 [Ep2c], and sequestosome 1 [P62]) and reduced phosphorylated- nuclear factor-kappa B (NF-κB) p65 subunit protein levels in the ileum of D-galactose-treated piglets (P < 0.05). It also enhanced microbial diversity and increased Bacteroidetes abundance while lowering Firmicutes abundance and the Firmicutes/Bacteroidetes ratio (P < 0.05). In addition, Spearman correlation analysis showed that ileal secretory immunoglobulin G (SIgG) was positively correlated with Acidobacteria, Chloroflexi, Streptococcus, and Actinobacteria, but negatively correlated with Firmicutes and Lactobacillus (P < 0.05). Collectively, these findings indicated that serine improves growth performance, mitigates chronic oxidative stress, and regulates NF-κB signaling and gut microbiota composition in weaned piglets.