ABSTRACT
The genomes of farmed animals, such as pigs, cattle and chickens are being mapped in order to identify genes controlling traits of economic importance. There is evidence of extensive conservation of genome organisation amongst higher vertebrates including these farm animals and more extensively characterised species, such as humans and mice. The primary goal of comparative mapping is to define relationships between species in terms of chromosomal evolution by mapping break-points and gene evolution by evaluating the structural and functional similarities between homologous genes. Amongst the benefits of comparative genome mapping are that a gene mapped in one species is effectively mapped in all other species for which the conserved genome structures have been identified. The observed conservation of genome organisation will allow the wealth of information being generated by the Human Genome Project to be exploited in the search for trait genes in farmed animals. Thus, comparative genome mapping in livestock will not only contribute to the understanding of genome evolution but is critical to current strategies for trait gene identification.
