|PEREZ O'BRIEN, ANA - University Of Natural Resources & Applied Life Sciences - Austria|
|HOLLER, DANIELA - University Of Natural Resources & Applied Life Sciences - Austria|
|BOISON, SOLOMON - University Of Natural Resources & Applied Life Sciences - Austria|
|MILANESI, MARCO - Collaborator|
|UTSUNOMIYA, YURI - Sao Paulo State University (UNESP)|
|CARVALHEIRO, ROBERTO - Universidade Estadual Paulista (UNESP)|
|NEVES, HAROLDO - Universidade Estadual Paulista (UNESP)|
|DA SILVA, MARCOS - Embrapa|
|BOMBA, LORENZO - Collaborator|
|Van Tassell, Curtis - Curt|
|AJMONE-MARSAN, PAOLO - Collaborator|
|GARCIA, FERNANDO - Sao Paulo State University (UNESP)|
|SOLKNER, JOHANN - University Of Natural Resources & Applied Life Sciences - Austria|
Submitted to: Genetics Selection Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2015
Publication Date: 4/17/2015
Citation: Perez O'Brien, A.M., Holler, D., Boison, S.A., Milanesi, M., Utsunomiya, Y.T., Carvalheiro, R., Neves, H.H., Da Silva, M.V., Bomba, L., Van Tassell, C.P., Sonstegard, T.S., Ajmone-Marsan, P., Garcia, F., Solkner, J. 2015. Levels of taurine introgression in the current Brazilian Nelore and Gir indicine cattle populations. Genetics Selection Evolution. 47(1):31.
Interpretive Summary: Nelore and Gir are the two most important indicine cattle breeds for production of beef and milk in Brazil, respectively. Historical records state these breeds were introduced to Brazil from the Indian subcontinent, crossed to local taurine animals to quickly increase the population size, and backcrossed to the original breeds to recover indicine adaptive and productive traits. Previous sparse DNA markers investigations have detected taurine admixture in these breeds. High density genome-wide analyses provide high resolution information about the genetic composition, estimate more precisely the levels and nature of taurine introgression, and shed some light into the history and strategies used for expansion of Nelore and Gir. This method of analysis can be used to identify potential retention of taurine genes important for improved beef production.
Technical Abstract: A high density panel of more than 777000 genome-wide single nucleotide polymorphisms (SNPs) were used to investigate the population structure of Nelore and Gir, compared to seven other populations worldwide. Principal Component Analysis and model-based ancestry estimation clearly separate the indicine, European taurine and African taurine ancestries. Less than 1% average taurine introgression was observed in the autosomal genomes of Nelore and Gir, while in Brahman 9% taurine ancestry was estimated. The analyses of mitochondrial SNPs from the commercial SNP chip were unable to clearly differentiate taurine and indicine haplotype grouping. The low levels of taurine ancestry observed in Nelore and Gir confirm historical records of crossbreeding, supporting strong directional selection against taurine haplotypes via backcrossing. Random sampling and genotyping of production herds 57 across the country is recommended for a more complete view of the admixture levels in commercial populations.