Molecular techniques used in the search for genetic determinants to improve meat quality

Abstract

An objective of the red meat industry is to improve the eating qualities of their product. This article focuses on some of the newer techniques used in identifying the genetic factors controlling the eating qualities of red meat animals. Identifying genes in an animal can be achieved either directly, or by linking with genetic markers. Linking a trait with genetic markers has become much easier with the recent development of microsatellite DNA-based genomic maps. The ultimate goal of most molecular biologists is to identify the DNA sequence that defines a unique genetic variant. If the actual sequence mutation is known, animals can be conclusively genotyped without pedigree information. Using microsatellite mapping, genetic variants can be defined in a range of DNA of approximately 100 to 1000 kilobases, which can include more the 50 to 100 genes. Current methods available for identifying specific genetic mutations can analyze approximately 0.4 to 2 kilobases per reaction, but a gene can be more than 60 kilobases long. To conclude, gene mapping can fix a genetic trait quickly, which is useful in controlled breeding programs, but the next step of identifying the genetic variants is very difficult. However, if a trait is defined biochemically, alternative molecular techniques can be applied to a few candidate genes, which might be a riskier approach, but it can give the best result of a simple genetic test. These tests can then be applied to identify and design meat animals according to specific food markets.