Buffalo meat is gaining popularity for its nutritional properties, such as its low fat and cholesterol content. However, it is often unsatisfactory to consumers due to its dark color and low tenderness. There is currently limited research on the regulatory mechanisms of buffalo meat quality. Xinglong buffalo are raised in the tropical Hainan region and are undergoing genetic improvement from draught to meat production. For the first time, we evaluated the meat quality traits of Xinglong buffalo using the longissimus dorsi muscle and compared them to Hainan cattle. Furthermore, we utilized a multi-omics approach combining transcriptomics and metabolomics to explore the underlying molecular mechanism regulating meat quality traits. We found that the Xinglong buffalo had significantly higher meat color redness but lower amino acid content and higher shear force compared to Hainan cattle. Differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were identified, with them being significantly enriched in nicotinic acid and nicotinamide metabolic and glycine, serine, and threonine metabolic pathways. The correlation analysis revealed that those genes and metabolites (such as: GAMT, GCSH, PNP, L-aspartic acid, NADP+, and glutathione) are significantly associated with meat color, tenderness, and amino acid content, indicating their potential as candidate genes and biological indicators associated with meat quality. This study contributes to the breed genetic improvement and enhancement of buffalo meat quality.

Pasteurella multocida (Pm) infection causes severe respiratory disease in goats. We investigated the effects of the Pm infection intratracheally on the histopathology, miRNA and mRNA expression dynamics in the lung of goats infected for 1, 2, 5 and 7 days. Pm infection caused fever, which significantly (p < 0.05) increased the body temperature of the goats from day 1 to 5. Haemotoxylin–eosin staining of the infected lung tissue showed characteristics of suppurative pneumonia with inflammatory cells infiltration and the lung structure destruction. During the Pm infection of the goats, compared with the control group, there were 3080, 3508, 2716 and 2675 differentially expressed genes and 42, 69, 91 and 108 significantly expressed miRNAs (|log₂Fold Change| > 1, p < 0.05) in the Pm_d1, Pm_d2, Pm_d5 and Pm_d7 groups, respectively. Five miRNAs and nine immune-related genes were selected for confirmation by reverse transcription–polymerase chain reaction. The results indicated that the expression patterns of the miRNAs and genes were consistent with those determined by next-generation sequencing. The differentially expressed genes were enriched in cytokine–cytokine receptor interaction, cell adhesion molecules, complement and coagulation cascades, tight junction and phagosome Kyoto Encyclopedia of Genes and Genomes pathways and cytokine production, leukocyte migration, myeloid leukocyte migration, cell periphery, plasma membrane, extracellular region part, extracellular region and other Gene Ontology terms. The differentially expressed genes were mapped to marker genes in human and mouse lung cells. The results showed the presence of some marker genes of the immune cells. Compared with the CK group, five miRNAs and 892 common genes were differentially expressed in the Pm_d1, Pm_d2, Pm_d5 and Pm_d7 groups. The target relationships between the common 5 miRNAs and 892 differentially expressed genes were explored and the miRNAs involved in the host immune reaction may act through the target genes. Our study characterized goats’ reaction in the lung from histopathological and molecular changes upon Pm infection, which will provide valuable information for understanding the responses in goats during Pm infection.

(1) Background: Mannheimia haemolytica (M. haemolytica) is an opportunistic pathogen and is mainly associated with respiratory diseases in cattle, sheep, and goats. (2) Methods: In this study, a mouse infection model was established using a M. haemolytica strain isolated from goats. Histopathological observations were conducted on various organs of the mice, and bacterial load determination and RNA-seq analysis were specifically performed on the spleens of the mice. (3) Results: The findings of this study suggest that chemokines, potentially present in the spleen of mice following a M. haemolytica challenge, may induce the migration of leukocytes to the spleen and suppress the release of pro-inflammatory factors through a negative feedback regulation mechanism. Additionally, an interesting observation was made regarding the potential of hematopoietic stem/progenitor cells congregating in the spleen to differentiate into immune cells, which could potentially collaborate with leukocytes in their efforts to counteract M. haemolytica invasion. (4) Conclusions: This study revealed the immune regulation mechanism induced by M. haemolytica in the mouse spleen, providing valuable insights into host–pathogen interactions and offering a theoretical basis for the prevention, control, and treatment of mannheimiosis.

Peripheral blood mononuclear cells (PBMCs) represent a critical component of the immune system, orchestrating both cellular and humoral responses while maintaining immunological homeostasis. This study investigates the PBMC immune response to Pasteurella multocida ( P. multocida ) infection in goats using single-cell RNA sequencing (scRNA-seq). PBMCs from goats before and after P. multocida infection were used for scRNA-seq), and pathological examinations were performed on different tissues of the infected hosts. Results demonstrated that recombinase polymerase amplification—lateral flow dipstick (RPA-LFD) detected P. multocida in peripheral blood and lungs, with histopathology confirming lesions. A total of 42 615 cells were annotated as nine cell subgroups, revealed dynamic alterations in immune cell populations, including significant increase in B cells and monocytes alongside decreased T cells and megakaryocytes post-infection. Further analysis identified 48 differentially expressed genes consistently modulated across comparison groups, with significant enrichment in immune-related Gene Ontology (GO) terms, as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways including IL-17 signaling pathway and cytokine–cytokine receptor interactions. Pseudotime trajectory uncovered four B cell and two T cell differentiation lineages. Inter-cell communication exhibited enhanced activity post-infection. Integration with RNA-seq data revealed key genes ( IL1R2 , RBM34 , EDEM3 , and MZB1 ) potentially critical in early infection. These findings substantially advance the understanding of PBMCs-mediated immune responses during the early stage of P. multocida infection in goats, identifying key genes and immune pathways. The study not only provides valuable insights into goat immunology but also establishes a foundation for developing improved diagnostic tools and targeted therapeutic interventions against this economically significant pathogen.

Mycoplasma capricolum subsp. capricolum (Mcc), a member of the Mycoplasma mycoides cluster, has a negative impact on the goat-breeding industry. However, little is known about the pathogenic mechanism of Mcc. This study infected mice using a previously isolated strain, Mcc HN-B. Hematoxylin and eosin staining, RNA sequencing, bioinformatic analyses, RT-qPCR, and immunohistochemistry were performed on mouse lung tissues. The results showed that 235 differentially expressed genes (DEGs) were identified. GO and KEGG enrichment analyses suggested that the DEGs were mainly associated with immune response, defensive response to bacteria, NF-kappa B signaling pathway, natural killer cell-mediated cytotoxicity, and T cell receptor signaling pathway. RT-qPCR verified the expression of Ccl5, Cd4, Cd28, Il2rb, Lck, Lat, Ptgs2, S100a8, S100a9, and Il-33. The up-regulation of S100A8 and S100A9 at the protein level was confirmed by immunohistochemistry. Moreover, RT-qPCR assays on Mcc HN-B-infected RAW264.7 cells also showed that the expression of S100a8 and S100a9 was elevated. S100A8 and S100A9 not only have diagnostic value in Mcc infection but also hold great significance in clarifying the pathogenic mechanism of Mcc. This study preliminarily elucidates the mechanism of Mcc HN-B-induced lung injury and provides a theoretical basis for further research on Mcc–host interactions.