Three Novel Players: PTK2B, SYK, and TNFRSF21 Were Identified to Be Involved in the Regulation of Bovine Mastitis Susceptibility via GWAS and Post-transcriptional Analysis

Abstract

Bovine mastitis is a common inflammatory disease caused by multiple factors in early lactation or dry period. Genome wide association studies (GWAS) can provide a convenient and effective strategy for understanding the biological basis of mastitis and better prevention. 2b-RADseq is a high-throughput sequencing technique that offers a powerful method for genome-wide genetic marker development and genotyping. In this study, single nucleotide polymorphisms (SNPs) of the immune-regulated gene correlative with mastitis were screened and identified by two stage association analysis via GWAS-2b-RADseq in Chinese Holstein cows. We have screened 10,058 high quality SNPs from 7,957,920 tags and calculated their allele frequencies. Twenty-seven significant SNPs were co-labeled in two GWAS analysis models [Bayesian ( P < 0.001) and Logistic regression ( P < 0.01)], and only three SNPs (rs75762330, C > T, PIC = 0.2999; rs88640083, A > G, PIC = 0.1676; rs20438858, G > A, PIC = 0.3366) were annotated to immune-regulated genes (PTK2B, SYK, and TNFRSF21). Identified three SNPs are located in non-coding regions with low or moderate genetic polymorphisms. However, independent sample population validation (Case-control study) data showed that three important SNPs (rs75762330, P < 0.025, OR > 1; rs88640083, P < 0.005, OR > 1; rs20438858, P < 0.001, OR < 1) were significantly associated with clinical mastitis trait. Importantly, PTK2B and SYK expression was down-regulated in both peripheral blood leukocytes (PBLs) of clinical mastitis cows and in vitro LPS ( E. coli )–stimulated bovine mammary epithelial cells, while TNFRSF21 was up-regulated. Under the same conditions, expression of Toll-like receptor 4 (TLR4), AKT1, and pro-inflammatory factors (IL-1β and IL-8) were also up-regulated. Interestingly, network analysis indicated that PTK2B and SYK are co-expressed in innate immune signaling pathway of Chinese Holstein. Taken together, these results provided strong evidence for the study of SNPs in bovine mastitis, and revealed the role of SYK, PTK2B, and TNFRSF21 in bovine mastitis susceptibility/tolerance.

Comparative Transcriptomic Analysis of the Pituitary Gland between Cattle Breeds Differing in Growth: Yunling Cattle and Leiqiong Cattle

“…Interestingly, SLC38A1 was abundantly expressed in the Yunling cattle's pituitary glands, and SLC38A3 was abundantly expressed in the Leiqiong cattle's pituitary glands. In our previous study, we also found that SLC38A4 was abundantly expressed in the Simmental cattle pituitary gland compared with Wenshan cattle [56]. There are many reports to prove that SLC38A1, SLC38A3, and SLC38A4 are involved in mammalian growth regulation, and SLC38A1 and SLC38A4 are primarily implicated in growth control of the embryo and can positively regulate prenatal growth by regulating the release of insulin [57].…”

Identification of SNPs Associated with Somatic Cell Score in Candidate Genes in Italian Holstein Friesian Bulls

“…A recent study, in which a genotyping-by-sequencing approach was used to find novel SNPs associated with milk traits, showed that the majority of identified SNPs were located within intergenic regions (69%), followed by intronic regions (25%), with only 3.46% of SNPs being coding variants [ 44 ]. Moreover, different studies found that conserved non-coding regions in introns and near genes show large allelic frequency shifts, similar in magnitude to missense variations, suggesting that they are critical for gene function regulation and evolution in many species [ 45 , 46 ]. Most of the significant SNPs detected in our investigation are located inside or in proximity to complete or partial lncRNA-like or miRNA-like sequences, or to repeated regions containing SINEs or LINEs, and it is now established that both intronic and LINE/SINEs repeats could lead to transcriptional regulation of the affected genes [ 47 ].…”

TNFRSF21 participates in Streptococcus agalactiae-induced inflammatory necrosis through the NLRP3 inflammasome pathway

“…Regarding the pathogenic molecular mechanism of mastitis caused by S. agalactiae, the experts' views are highly variable, and no conclusions have been reached. Our previous research found that TNSFRSF21 genetic polymorphisms are signi cantly related to the susceptibility and tolerance of dairy cow mastitis through a genome-wide association analysis [31]; however, the role of TNFRSF21 in S. agalactiae-induced mastitis remains unknown. In this study, we found that the mammary gland tissues of the mice infected with S. agalactiae (bacterial solution with a concentration of 1 × 10 9 CFU/mL) displayed more severe histopathological damage than that of the control groups, and the level of caspase-1, IL-1β, NLRP3, and TNFRSF21 expression was signi cantly increased.…”