Genetic polymorphisms in immune- and inflammation-associated genes and their association with bovine mastitis resistance/susceptibility

Abstract

Bovine mastitis, the inflammation of the mammary gland, is a contagious disease characterized by chemical and physical changes in milk and pathological changes in udder tissues. Depressed immunity and higher expression of inflammatory cytokines with an elevated milk somatic cell count can be observed during mastitis in dairy cattle. The use of somatic cell count (SCC) and somatic cell score (SCS) as correlated traits in the indirect selection of animals against mastitis resistance is in progress globally. Traditional breeding for mastitis resistance seems difficult because of the low heritability (0.10-0.16) of SCC/SCS and clinical mastitis. Thus, genetic-marker-selective breeding to improve host genetics has attracted considerable attention worldwide. Moreover, genomic selection has been found to be an effective and fast method of screening for dairy cattle that are genetically resistant and susceptible to mastitis at a very early age. The current review discusses and summarizes the candidate gene approach using polymorphisms in immune- and inflammation-linked genes (CD4, CD14, CD46, TRAPPC9, JAK2, Tf, Lf, TLRs, CXCL8, CXCR1, CXCR2, C4A, C5, MASP2, MBL1, MBL2, LBP, NCF1, NCF4, MASP2, A2M, and CLU, etc.) and their related signaling pathways (Staphylococcus aureus infection signaling, Toll-like receptor signaling, NF-kappa B signaling pathway, Cytokine-cytokine receptor, and Complement and coagulation cascades, etc.) associated with mastitis resistance and susceptibility phenotypic traits (IL-6, interferon-gamma (IFN-γ), IL17, IL8, SCS, and SCC) in dairy cattle.

Divergent Immune Responses to Minor Bovine Mastitis-Causing Pathogens

“…These findings suggest that different pathogens may utilize distinct MAMPs and TLRs for recognition by bovine circulating/milk neutrophils, potentially influencing the subsequent immune response [ 16 , 25 , 27 ]. While bovine neutrophils might have evolved specific recognition mechanisms for different levels of pathogenic threat, mutations in the coding regions of TLR2 , 4 , and 6 genes elevated mastitis susceptibility, suggesting a crucial genetic link to resistance [ 29 , 30 ]. The minimal TLR2 response to minor pathogens could indicate alternative pathways for the recognition and/or prioritization of other defense mechanisms like phagocytosis, as well as the mitigation of apoptosis [ 25 , 31 ].…”

Enhancing bovine immune, antioxidant and anti-inflammatory responses with vitamins, rumen-protected amino acids, and trace minerals to prevent periparturient mastitis

“…Mastitis, characterized by the inflammation of mammary glands (1,2), is intricately associated with immune suppression and an imbalance between free radicals and antioxidants within the animal's physiological framework (3)(4)(5). Dairy cows confront the challenge of negative energy balance (NEB) during the periparturient period, precipitating a cascade of detrimental effects such as reduced dry intake, metabolic stress, hormonal fluctuations, heightened oxidative stress, and compromised immune responses (6,7).…”

Advancements in copy number variation screening in herbivorous livestock genomes and their association with phenotypic traits

“…In recent years, the exploration of genomic variation has emerged as a central focus of scientific inquiry in the fields of animal production and health regulation, as evidenced by numerous studies (4)(5)(6)(7)(8)(9)(10). This emphasis on genetic variation holds significant significance in our quest to comprehend the intricate interplay between genetic diversity and a wide array of phenotypic and economic traits exhibited by animals (11)(12)(13).…”