Submitted to: Animal Genetics International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 14, 2000
Publication Date: N/A
Technical Abstract: Interleukin (IL)-8 encodes a pro-inflammatory cytokine that plays a central role in cell-mediated immunity by attracting and activating neutrophils in the early stages of host defense against bacterial invasion. This report estimates the genetic structure of commercial cattle populations for the IL8 locus, a requisite for studies designed to test whether IL8 alleles are ecorrelated with infection phenotypes. Five previously unknown single nucleotide polymorphism(SNP) markers were identified by electrophoretic DNA sequencing of two IL8 introns that were amplified from a novel collection of 96 individuals representing 17 popular cattle breeds. Assays for automated genotype scoring by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were developed and used to independently verify the five new SNP alleles and two previously known SNPs. These MALDI-TOF MS assays were used to determine the allele and genotype frequencies of breed groups in the SNP discovery panel. Three haplotypes for the set of seven SNPs were assigned and confirmed by analyzing segregation in 313 individuals from MARC reference population. Two additional haplotypes were unambiguously deduced from a homozygous sire and an allele cloned from a heterozygous sire, respectively. A sixth haplotype was identified in a related species, American bison, but was not present in the group of cattle analyzed. The identification of IL8 haplotype structures from commercial populations and the development of robust automated genotype assays provides a means for efficiently using IL8 markers in a variety of genetic studies in production environments.