The analyses, which involved comparing the domestic cattle genome sequence to those of the human, dog, mouse, rat, opossum and platypus, provide critical insights into the structure and function of the human genome. The findings will also assist researchers working to improve the quality and safety of beef and dairy products. In addition, genomic information can be used to develop better strategies for treating and preventing diseases that affect cattle. Some of those diseases, including bovine spongiform encephalopathy, commonly known as mad cow disease, also can be transmitted although very rarely to humans.
Like humans and other mammals, the chromosomes of domestic cattle contain segmental duplications, which are large, almost identical copes of DNA present in at least two locations in a genome. Segmental duplications in the human genome are associated with a variety of human disorders, including a form of mental retardation and other neurological and birth defects.
In the domestic cattle genome, researchers found that some of these chromosomal rearrangements affect genes related to immunity, metabolism, digestion, reproduction and lactation. For instance, researchers think some of these changes may explain the unique ability of cattle to convert grass and other low-energy food sources into high-energy muscle, fat and milk.
Segmental duplications in the domestic cattle genome have also resulted in specialized roles for genes involved in immune response, such as those that make antimicrobial proteins in milk and their intestines. Researchers think these genes developed over time in response to the diversity of microbes that domestic cattle encounter and the vulnerability of animals that live in large herds to the spread of infectious diseases.
The breed of cattle selected for genome sequencing was Hereford, which is used in beef production. The effort to sequence a
|Contact: Geoff Spencer|
NIH/National Human Genome Research Institute