02333nam a2200289 a 450000100080000000500110000800800410001910000190006024501060007926001500018550000130033552013880034865000140173665000180175065000170176865300400178570000220182570000170184770000200186470000250188470000230190970000230193270000160195570000230197170000260199470000230202018629302018-08-21       2010    bl uuuu     u00u1 u    #d1 aMACHADO, M. A.  aFine-mapping of BTA 10 and BTA 11 for tick resistance in Gyr x Holstein cross.h[electronic resource]  aIn: WORLD CONGRESS ON GENETICS APPLIED TO LIVESTOCK PRODUCTION, 9., 2010, Leipzig. Proceedings... Leipzig: German Society fo Animal Sciencec2010  a1 CD-ROM  aIn tropical regions, the incidence of the bovine tick Rhipicephalus (Boophilus) microplus deeply impacts dairy cattle production systems, decreasing milk production and affecting reproduction traits and eventually may cause the death of highly susceptible animals. The identification of DNA markers linked to tick resistance would provide a better strategy for selecting resistant animals. Mapping QTL and identification of causative genes that affect tick resistance will allow the use of marker assisted selection (MAS) in breeding programs. MAS could be used to pre-select young animals, shortening generation interval and increasing genetic gain (Beckmann and Soller, 1987). Previous studies by our group (Azevedo et al., 2009) detected six QTL for tick resistance in a Gyr x Holstein F2 population. These QTL were detected with moderate resolution because the distances between markers were relatively large. In order to reduce the confidence intervals, new markers were added in regions where QTL were detected. Typically, confidence intervals for the most likely QTL positions are in the order of 20 to 30 cM. Since most practical implementations of marker information require QTL to be mapped to intervals of 1 to 2 cM, methods of higher precision are needed to refine the region (Olsen et al., 2004). The aim of the present study was refine the position of the detected QTL.  aCarrapato  aGado Leiteiro  aResistência  aRhipicephalus (Boophilus) microplus1 aAZEVEDO, A. L. S.1 aGASPARIN, G.1 aBERNARDO, K. B.1 aPEIXOTO, M. G. C. D.1 aSILVA, M. V. G. B.1 aPRATA, M. C. de A.1 aFURLONG, J.1 aPIRES, M. de F. A.1 aREGITANO, L. C. de A.1 aVERNEQUE, R. da S.