Genome wide scan for quantitative trait loci affecting tick resistance in cattle (<it>Bos taurus</it> × <it>Bos indicus</it>)

• Main Authors: Guimarães Simone EF, Regitano Luciana CA, da Silva Marcos, Furlong John, Prata Márcia, de Freitas Célio, CD Peixoto Maria, Pires Maria A, Teodoro Roberto L, S Azevedo Ana, Machado Marco, Coutinho Luiz L, Gasparin Gustavo, Verneque Rui S
• Format: Article
• Language: English
• Published: BMC 2010-04-01
• Series: BMC Genomics
• Online Access: http://www.biomedcentral.com/1471-2164/11/280

<p><b>Abstract</b></p> <p><b>Background</b></p> <p>In tropical countries, losses caused by bovine tick <it>Rhipicephalus (Boophilus) microplus</it> infestation have a tremendous economic impact on cattle production systems. Genetic variation between <it>Bos taurus</it> and <it>Bos indicus</it> to tick resistance and molecular biology tools might allow for the identification of molecular markers linked to resistance traits that could be used as an auxiliary tool in selection programs. The objective of this work was to identify QTL associated with tick resistance/susceptibility in a bovine F2 population derived from the Gyr (<it>Bos indicus</it>) × Holstein (<it>Bos taurus</it>) cross.</p> <p>Results</p> <p>Through a whole genome scan with microsatellite markers, we were able to map six genomic regions associated with bovine tick resistance. For most QTL, we have found that depending on the tick evaluation season (dry and rainy) different sets of genes could be involved in the resistance mechanism. We identified dry season specific QTL on BTA 2 and 10, rainy season specific QTL on BTA 5, 11 and 27. We also found a highly significant genome wide QTL for both dry and rainy seasons in the central region of BTA 23.</p> <p>Conclusions</p> <p>The experimental F2 population derived from Gyr × Holstein cross successfully allowed the identification of six highly significant QTL associated with tick resistance in cattle. QTL located on BTA 23 might be related with the bovine histocompatibility complex. Further investigation of these QTL will help to isolate candidate genes involved with tick resistance in cattle.</p>