Geographic distribution and frequency of taurine Bos taurus and zebu B. indicus Y chromosome incidence amongst Argentine and Bolivian Creole cattle breeds

GIOVAMBATTISTA, G.; RIPOLI, M.V.; DE LUCA, J.C.; MIROL, P.M.; LIRÓN, J.P.; DULOUT, F. N.

ANIMAL GENETICS

WILEY-BLACKWELL PUBLISHING, INC

Año: 2000 vol. 31 p. 302 - 305

0268-9146

The geographic distribution and frequency of Bos taurus and Bos indicus Y chromosome haplotypes amongst Argentine and Bolivian Creole cattle breeds were studied, using cytogenetic and molecular genetic techniques. A complete correspondence between Y chromosome morphology and the haplotype of the Y-linked microsatellite marker INRA 124 was found in all males examined. The taurine and indicine haplotypes were detected in 85·7 and 14·3% of the males studied, respectively, although these frequencies varied amongst the different breeds examined. The geographic distribution of this polymorphism suggests a pattern of zebu introgression in South America. The highest frequencies of the Zebu Y-chromosome are found in Brazilian populations (43–90%), in the eastern part of the continent, while it is absent in the southermost breeds from Uruguay and Argentina. Bolivan breeds, at the centre of the continent, exhibit intermediate values (17–41%). This east:west and north:south gradient of male Zebu introgression could be explained by historical events and environmental factors.Bos taurus and Bos indicus Y chromosome haplotypes amongst Argentine and Bolivian Creole cattle breeds were studied, using cytogenetic and molecular genetic techniques. A complete correspondence between Y chromosome morphology and the haplotype of the Y-linked microsatellite marker INRA 124 was found in all males examined. The taurine and indicine haplotypes were detected in 85·7 and 14·3% of the males studied, respectively, although these frequencies varied amongst the different breeds examined. The geographic distribution of this polymorphism suggests a pattern of zebu introgression in South America. The highest frequencies of the Zebu Y-chromosome are found in Brazilian populations (43–90%), in the eastern part of the continent, while it is absent in the southermost breeds from Uruguay and Argentina. Bolivan breeds, at the centre of the continent, exhibit intermediate values (17–41%). This east:west and north:south gradient of male Zebu introgression could be explained by historical events and environmental factors.