title: Genome-wide association study for somatic cell score in Valdostana Red Pied cattle breed using pooled DNA.
abstract: BACKGROUND
  Mastitis is a major disease of dairy cattle occurring in response to environmental exposure to infective agents with a great economic impact on dairy industry. Somatic cell count (SCC) and its log transformation in somatic cell score (SCS) are traits that have been used as indirect measures of resistance to mastitis for decades in selective breeding. A selective DNA pooling (SDP) approach was applied to identify Quantitative Trait Loci (QTL) for SCS in Valdostana Red Pied cattle using the Illumina Bovine HD BeadChip.
  
  
  RESULTS
  A total of 171 SNPs reached the genome-wide significance for association with SCS. Fifty-two SNPs were annotated within genes, some of those involved in the immune response to mastitis. On BTAs 1, 2, 3, 4, 9, 13, 15, 17, 21 and 22 the largest number of markers in association to the trait was found. These regions identified novel genomic regions related to mastitis (1-Mb SNP windows) and confirmed those already mapped. The largest number of significant SNPs exceeding the threshold for genome-wide significant signal was found on BTA 15, located at 50.43-51.63 Mb.
  
  
  CONCLUSIONS
  The genomic regions identified in this study contribute to a better understanding of the genetic control of the mastitis immune response in cattle and may allow the inclusion of more detailed QTL information in selection programs.
authors.forename: Maria G
authors.initials: MG
authors.lastname: Strillacci
authors.forename: Erika
authors.initials: E
authors.lastname: Frigo
authors.forename: Fausta
authors.initials: F
authors.lastname: Schiavini
authors.forename: Antonia B
authors.initials: AB
authors.lastname: Samoré
authors.forename: Fabiola
authors.initials: F
authors.lastname: Canavesi
authors.forename: Mario
authors.initials: M
authors.lastname: Vevey
authors.forename: Maria C
authors.initials: MC
authors.lastname: Cozzi
authors.forename: Morris
authors.initials: M
authors.lastname: Soller
authors.forename: Ehud
authors.initials: E
authors.lastname: Lipkin
authors.affiliation: Department of Health, Animal Science and Food Safety (VESPA), University of Milan, Via Celoria 10, Milan, 20133, Italy. alessandro.bagnato@unimi.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Bagnato
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics*; D002874:Chromosome Mapping / Q000662:veterinary*; D005260:Female; D055106:Genome-Wide Association Study; D005838:Genotype; D008297:Male; D008414:Mastitis, Bovine / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci