Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/11/2004
Publication Date: 9/24/2004
Citation: Casas, E., Thallman, R.M. 2004. The challenge of molecular genetics in animal breeding. Proceedings of Biotechnology for Livestock in the 21st Century. September 20-24, 2004. Montecillo, Mexico. pp. 27-39. Interpretive Summary: It has been possible to identify chromosomal segments carrying genes affecting production traits. Variation in individual genes having major impact on phenotypes in cattle have been identified. However, approaches to develop tests to assess the genetic merit for important production traits are being developed. The objective of this review is to describe the methodology used to develop genetic markers, and their potential use in selection programs. Some discussion centers on how this information will be used to improve economically relevant traits.
Technical Abstract: The objective of the present review was to describe the detected quantitative trait loci (QTL) and how to select candidate genes under the QTL, develop genetic markers and use them in breeding evaluations. Productive and carcass composition traits are quantitative in nature. Searches for the detection of QTL have been identified for growth and carcass composition traits. The genomic region under the QTL is the region where candidate genes reside. Genetic markers need to be developed from the sequence of the gene. These markers need to be evaluated in several populations to establish if the genetic markers developed are associated with the quantitative trait of interest. Once this association has been established, it will be possible to use the genetic marker information in animal breeding programs.