Background and overview of comparative genomics

Abstract

Comparative genomics - the cross-referencing of information on genome organization between species - provides an additional dimension to the Human Genome Project and can derive much information from it for the benefit of animal health and animal breeding. Arrangements of genes and other DNA sequences may be determined by a variety of genetic and physical techniques, at resolutions from the gross cytological level to the level of the single base pair. Gross arrangements and rearrangements can also be charted by comparative chromosome painting. Genome organization may then be compared across mammal - and other vertebrate - species. Genetic mapping is well advanced in several live-stock species as well as rodent model species, and outline maps are available for at least 30 mammal species in 8 orders. At the time of this writing, maps are being rapidly constructed for chicken and fish species. Comparisons, even over vast evolutionary time scales, show that the mammal genome - indeed, the vertebrate genome - has been highly conserved. Thus information about location and function of genes is directly transferable across species and should greatly speed up the search for genes that specify inherited diseases in domestic mammals and humans as well as genes that specify economically important traits.