Identification of regulatory elements in 5' regions of chemokine genes is fundamental for understanding chemokine gene expression in response to infection diseases. The CXCR1 receptor is expressed on the surface of neutrophils and interacts primarily with CXCL8 (IL-8), the most potent chemoattractant for neutrophils. The aim of this study was to characterize the 5' upstream region (2.1 kb) of the bovine CXCR1 chemokine receptor gene for polymorphism content and to identify in silico potential transcription-factor binding sites. The 5' flanking region was found by mining the NCBI GenBank (www.ncbi.nlm.nih.gov/). A DNA sequence from the whole genome shotgun sequence project with reference number AC150887.4 contained the CXCR1 5' flanking sequence. Computer analysis revealed potential binding sites for the transcription factors nuclear factor kappaB (NF-kappaB), binding factor GATA-1, barbiturate inducible element (Barbie), nuclear factor of activated T-cells, and activator protein 1. Polymorphism discovery in this region was conducted by constructing an inclusive DNA pool including 2 phenotypic extreme groups, 20 bulls with high estimated breeding values (EBV) for somatic cell score (SCS), and 20 bulls with low EBV for SCS. Independent amplicons along the 5' flanking region of bovine CXCR1 were generated for polymorphism discovery by sequencing. Three novel single nucleotide polymorphisms (SNP), CXCR1c.-344T>C, CXCR1c.-1768T>A, and CXCR1c.-1830A>G, and a previously identified SNP in the coding region, CXCR1c.777G>C, were identified. The 4 SNP were genotyped in Canadian Holstein bulls (n = 338) using tetra-primer amplification refractory mutation system (ARMS)-PCR. Average allele substitution effects were estimated to investigate associations between the 4 SNP and EBV for SCS in first, second, and third and later lactations. Multiple trait analysis revealed that the SNP CXCR1c.-1768T>A was associated with EBV for SCS in the first and second lactations and over all 3 lactations. Haplotype analysis substantiated this association with EBV for SCS in the first lactation. Given the location of SNP CXCR1c.-1768T>A and the surrounding potential binding recognition sequences for NF-kappaB, GATA-1, and Barbie transcription-factors, this SNP may be implicated in gene regulation and warrants further research.

The aim of this study was to identify the presence of SNPs in the chemokine genes CCL2 and IL8 and the chemokine receptor genes IL8RA and CCR2, and assess their potential contribution to variation in estimated breeding values (EBVs) for somatic cell score (SCS) and four other traits in Canadian Holstein bulls. Pools of DNA for bulls with high (H) and low (L) EBVs for SCS were used for identification of 11 SNPs. Two unreported SNPs were found in the CCL2 gene and one SNP was found in the CCR2 gene. Previously reported SNPs (three in the IL8 gene and five in the IL8RA chemokine receptor) were also identified. Two SNPs in CCL2, three in IL8, one in IL8RA and one in CCR2 were genotyped in Canadian Holstein bulls (n = 338) using tetra primer ARMS-PCR. We investigated associations of these seven polymorphisms with three production traits (milk yield, fat yield and protein yield) and one conformation trait related to mastitis (udder depth). The allele substitution effect for the CCL2 rs41255713:T>C SNP was significant at an experimental-wise level for milk yield (247.5 +/- 79.9 kg) and protein yield (7.4 +/- 2.3 kg) EBVs (P T SNP on SCS was significant at the comparison-wise level (-0.04 +/- 0.02, P = 0.05), which might indicate a possible association in support of other published studies. Lastly, we assigned CCR2 to BTA22q24, where a previously QTL for SCS was identified.

Background: Toll-like receptor-2 (TLR2) and Caspase Recruitment Domain 15 (CARD15) are important pattern recognition receptors that play a role in the initiation of the inflammatory and subsequent immune response. They have been previously identified as susceptibility loci for inflammatory bowel diseases in humans and are, therefore, suitable candidate genes for inflammatory disease resistance in cattle. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the bovine TLR2 and CARD15 and evaluate the association of these SNPs with health and production traits in a population of Canadian Holstein bulls.

SummaryThe objective of this study was to determine the genetic diversity of creole cattle in northwestern Mexico using the BoLA-DRB3.2 locus of the Major Histocompatibility Complex (MHC). A total of 56 creole cattle were sampled from five communities; in the state of Chihuahua (Cerocahui, Guadalupe y Calvo and Cuauhtémoc) and in the state of Baja California Sur (La Paz and Mulegé). The BoLA-DRB3.2 locus was genotyped by PCR-RFLP assay. Thirty-nine alleles were identified, out of which 14 had not been previously reported. The average level of inbreeding in all populations analyzed wasFIS= 0.09 (P< 0.0001), but only two populations (Cerocahui and Guadalupe y Calvo) showed an excess of homozygotes (P< 0.05). The breed differentiation in all populations studied wasFSC= 0.068 (P< 0.0001). The smallest genetic distance was between La Paz and Mulegé (0.022); but Mulegé presented smaller distances (0.028–0.053) with the populations of La Paz (0.071–0.083) and with Chihuahua. Baja California Sur populations are grouped in a separate branch than Chihuahua populations. We conclude that creole cattle from Baja California Sur and Chihuahua show high genetic diversity in the locus BoLA-DRB3.2.

The objectives of the current study were 1) to compare sample preparation workflows and quantitative real-time polymerase chain reaction assays (qPCR) as currently used in veterinary diagnostic laboratories with a study protocol utilizing commercially available reagents for individual Tritrichomonas foetus testing, 2) to assess the accuracy of pooling cultured smegma samples followed by extraction and qPCR testing as used in the study laboratory, and 3) to assess the specificity of the currently used primers and probes by sequencing all positive and presumptive positive samples identified in the study laboratory in an attempt to capture any nucleotide variability between T. foetus isolates and to rule out false-positive results possibly due to Simplicimonas moskowitzi. Eight hundred three cultured smegma samples were collected from different regions of the United States with the collaboration of 5 veterinary testing laboratories. The samples were processed individually by the respective laboratories, and then sent to the study laboratory and retested using the study protocol. Comparison testing showed an overall agreement of 95.89% between the veterinary testing laboratories and the study laboratory. One hundred seventy-six positive or presumptive positive samples plus 625 negative qPCR samples were combined and retested using a pooling protocol. Pools consisted of 1 positive sample and 4 negative samples (1/5). These pools were processed using the same study laboratory protocols, and 96% of the positive samples were detected in these pools. Nested PCR followed by sequencing confirmed 175 of the 178 samples classified as positive or presumptive positive in the study laboratory as containing T. foetus–specific DNA.