What is a genome?
The word genome is a combination of two words, gene and chromosome. All the genetic material of an organism together is known as a genome. The genes, chromosomes and DNA in the genome determine the characteristics of the organism. DNA has four chemical bases, Adenine, Thymine, Cytosine and Guanine. The innumerable different possible arrangements of these chemical bases are what ensure the wide ranging diversity on the planet.
What have the scientists done about the cow genome?
A group of over 300 scientists from 25 countries, working over a period of six years, have successfully mapped the genome of an eight-year old Hereford cow from Montana. The overall cost of the project, according to news reports, was $53 million.
A cow genome contains all the genetic information about the cow. It contains precise information about what makes the cow a cow, rather like a blueprint. It sheds a revealing light on the importance of genetic make-up.
The mapped cow genome provides information about which genes give the cow immunity from certain diseases, which genes make the cow's metabolism work, which genes help carry out the cow's digestion processes, which genes decide what kind of calf the cow is likely to produce, which genes help step up the milk production and so on.
Why is this a milestone in genome science?
Having this kind of information at hand can be invaluable to farmers. They can select the best animals for breeding and produce high quality calves. They can breed animals that produce high yields of milk and give better quality of beef. They can also produce animals that are sturdy and healthy, thus reducing veterinary bills and overall farm costs.
The researchers are also comparing the Hereford cow genome sequences with the genome sequences of other cattle breeds. They have mapped the differences in genes that affect milk and beef production. They hope to use the information not just for better cattle breeding, but also to find a way for reducing environmental damage caused by large cattle herds.
What else have the scientists learned from mapping the cow genome?
Cows have about 22,000 genes. Of these, 14,000 genes are the same as those in other mammals. The remaining 8000 genes are unique to cows, and it is these unique genes that give cows their characteristic features.
Since humans and cows share 14,000 similar genes, bovine genetic research can shed some illuminating light on human genome research as well. The researchers found that chromosomes in the cow genome are organized in a manner similar to the chromosomal arrangement in humans. Researchers hope their research will offer important clues to human health and disease.