Submitted to: World Congress of Genetics Applied in Livestock Production
Publication Type: Proceedings
Publication Acceptance Date: 9/26/2006
Publication Date: 10/10/2006
Citation: Regitano, L., Miyata, M., Gasparin, G., Coutinho, L.L., Martinez, M.L., Machado, M.A., Silva, M., Campos, A.L., Sonstegard, T.S. 2006. A QTL for resistance to Boophilus microplus maps to bovine chromosome 14. Proceedings of 8th World Congress of Genetics Applied in Livestock Production 8(15-32):1-4. Interpretive Summary: The use of microsatellite markers in an interval mapping analysis, using a bovine F2 Holstein x Gyr population, has shown to be an appropriate strategy for mapping tick resistance associated QTL. With only 258 animals, it was possible to detect a QTL of statistical significance associated to resistance or susceptibility to the Boophilus microplus tick. This is the first report of QTL for tick indicator traits. In this study, a QTL was found on chromosome 14. Given the difficulty of tick resistance evaluation, and the impact of this parasite on both cattle production and on the environment, once confirmed in other populations, application of this QTL information on MAS would be of great benefit in tropical and sub-tropical cattle regions of Brazil and the U.S., respectively.
Technical Abstract: In countries of tropical climate like Brazil, the tick Boophilus microplus causes damage to cattle. The main used strategy in the control or eradication of tick is the use of carrapaticides and vaccines. Currently marker assisted selection (MAS) is one of the tools suggested to exploit the genetic variation for resistance to parasites. The objective of this paper was to identify Quantitative Trait Loci (QTL) for resistance to the tick Boophilus microplus on BTA14. An experimental F2 Holstein-Gyr population was produced and a total of 258 F2 animals had tick counts data available for QTL analysis. A significant QTL (P<0.01) was found on BTA 14 for tick resistance at 47 cM from the centromere. Once confirmed in other populations, application of this QTL information on MAS would be of great benefit for tick control in the tropics.