Cow genes elucidate evolution
April 24, 2009
A Simon Fraser University-led research team’s analysis of the first genomic sequence of a mammalian livestock animal provides clues about cattle’s evolution. The team’s look at a Hereford cow’s genome may also help scientists pinpoint which genes contribute to disease susceptibility, milk production and other traits.
Working with colleagues at Trinity College Dublin in Ireland, the SFU-led research team was part of a more than 300-member international research consortium spanning 25 countries.
The Bovine Genome Sequencing Project mapped the genome of a Hereford cow—one of North America’s primary breeds for beef production. An associated Bovine HapMap Project, which built upon the sequencing project, mapped the genetic diversity of 19 breeds of cattle worldwide.
The journal Science has published the results of both studies and the BioMed Central journal series has published companion papers about the work.
David Lynn, a postdoctoral research associate in SFU associate professor Fiona Brinkman’s lab, led the analysis of adaptive evolution in the bovine genome. The team discovered that 70 of the cow’s 22,000 genes evolved more rapidly than expected.
Ten of these genes control immune functions; the rest govern a number of biological processes, including milk production.
Scientists have long believed that organisms’ immune-related efforts to overcome infectious diseases have led to adaptive evolution,” explains Lynn, an Irish born geneticist. “Our research helps cement the theory that genes governing the immune system actually evolve more rapidly than other genes to help ensure a species’ survival.”
Lynn predicts that as analysis procedures improve, scientists may discover even more genes that have been subject to adaptive evolution. “This is a start,” observes Lynn, “and informs scientists about which genes are most likely involved in increasing and diminishing cattle’s disease susceptibility.
Our research could help the cattle industry breed livestock that are more resistant to infectious diseases, such as mastitis, a bacterial disease affecting the udder system. Such diseases are dramatically undermining milk production in a world with a rapidly increasing human population that needs food.”
SFU faculty members, Fiona Brinkman, Steven Jones, Marco Marra and Rob Holt, and a graduate student in Brinkman’s lab, Mathew Whiteside, were also involved in these projects. Jones and Marra led sections that involved assembly and analysis of the bovine genome sequence at Canada’s Michael Smith Genome Science Centre in Vancouver.