Characterization of DEFB103 gene structure, gene expression and its haplotype association with three common diseases in Beef and Holstein cattle
The DEFB103 gene is a member of the β-defensin gene family, and it has not been well studied in cattle. In this study DEFB103 gene expression, gene structure and its haplotypes association with three diseases were studied. DEFB103 gene expression was profiled for 27 tissues in nine two-week old calves and the transcript was most abundant in tissues with stratified squamous epithelium. An age-dependent decrease (P <0.05) in DEFB103 gene expression was observed in buccal epithelium when comparing healthy two-week old and 10- to 12-month-old calves. A bovine herpesvirus-1 respiratory infection did, however, significantly (P < 0.05) up-regulate DEFB103 gene expression in the buccal epithelium of 6- to 8-month-old calves. Immunohistochemistry was used to identify cells expressing DEFB103 protein within tissues with stratified squamous epitheliums to confirm the DEFB103 gene expression results. DEFB103 protein was most abundant in basal epithelial cells and was present in these cells before birth. A close association was observed between the dendritic cells and epithelial cells expressing DEFB103 in both the fetus and newborn calf, and this is consistent with the β-defensin regulatory effect on dendritic cell responses. DEFB103 cDNA boundaries were determined using RT-PCR. A newly discovered non-coding exon 1a and a 261 bp intron 1a were identified in cattle. At least two complete copies of DEFB103 with an ATG start codon are present in cDNA in some cattle. DEFB103 sequence assemblies and partial cloning cloning sequences revealed two types of deletion (4-bp and 8-bp) in the 5′UTR. Two novel SNPs were identified in the 5′UTR of the DEFB103 (c.-383A>G, c.-241G>A) in addition to five (c.-319A>G, c.-264C>T, c.-69A>G, c.-42A>G, and c.-34G>A) previously reported SNPs in the 5′UTR of DEFB103 gene. The association among three diseases and four haploid haplotypes was studied. Diploid haplotype analysis shows a trend toward increased risk of mastitis (1/4; P= 0.053) in the Saskatchewan population and a decreased risk of mastitis (4/4; P= 0.06) in the Pennsylvania population. An inconsistent trend toward decreased (2; P=0.09) or increased (4; P=0.09) risk of mastitis also were determined when the haploid haplotypes were compared to others in the Saskatchewan and the Pennsylvania populations. There was no significant difference in the haplotype frequencies of the control group and cattle with Cancer-eye (P= 0.43). No significant difference was determined in the survival curve (P=0.50), the level of serum haptoglobin (P=0.65), or the level of interferon-gamma (P= 0.50) between cattle with diploid haplotypes 2/2 and 2/4 and shipping fever.
DegreeMaster of Science (M.Sc.)
DepartmentAnimal and Poultry Science
CommitteeSchmutz, Sheila M; Griebel, Philip; Laarveld, Bernard; Buchanan, Fiona C; Van Kessel, Andrew
Copyright DateMay 2016
Copy number variation