title: Geographic distribution of haplotype diversity at the bovine casein locus.
abstract: The genetic diversity of the casein locus in cattle was studied on the basis of haplotype analysis. Consideration of recently described genetic variants of the casein genes which to date have not been the subject of diversity studies, allowed the identification of new haplotypes. Genotyping of 30 cattle breeds from four continents revealed a geographically associated distribution of haplotypes, mainly defined by frequencies of alleles at CSN1S1 and CSN3. The genetic diversity within taurine breeds in Europe was found to decrease significantly from the south to the north and from the east to the west. Such geographic patterns of cattle genetic variation at the casein locus may be a result of the domestication process of modern cattle as well as geographically differentiated natural or artificial selection. The comparison of African Bos taurus and Bos indicus breeds allowed the identification of several Bos indicus specific haplotypes (CSN1S1*C-CSN2*A2-CSN3*AI / CSN3*H) that are not found in pure taurine breeds. The occurrence of such haplotypes in southern European breeds also suggests that an introgression of indicine genes into taurine breeds could have contributed to the distribution of the genetic variation observed.
authors.affiliation: Department for Animal Breeding and Genetics, Justus-Liebig University of Giessen, Germany.
authors.forename: Oliver C
authors.initials: OC
authors.lastname: Jann
authors.forename: Eveline M
authors.initials: EM
authors.lastname: Ibeagha-Awemu
authors.forename: Ceyhan
authors.initials: C
authors.lastname: Ozbeyaz
authors.forename: Pilar
authors.initials: P
authors.lastname: Zaragoza
authors.forename: John L
authors.initials: JL
authors.lastname: Williams
authors.forename: Paolo
authors.initials: P
authors.lastname: Ajmone-Marsan
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Lenstra
authors.forename: Katy
authors.initials: K
authors.lastname: Moazami-Goudarzi
authors.forename: Georg
authors.initials: G
authors.lastname: Erhardt
mesh_terms: D000818:Animals; D002364:Caseins / Q000235:genetics*; D002417:Cattle / Q000235:genetics*; D005787:Gene Frequency; D014644:Genetic Variation; D005843:Geography; D006239:Haplotypes / Q000235:genetics*; D008957:Models, Genetic; D010802:Phylogeny; D025341:Principal Component Analysis; D013045:Species Specificity
chemical_list: D002364:Caseins