How did the Dog Genome Project Begin?
This aspect of genetics research came in several stages. First of all the genome of a female Boxer dog called Tasha was sequenced. The Boxer was seen as a representative sample of a purebred animal. She acted as a reference sequence for the analysis of the genomes of 10 breeds, and other related canine species such as the coyote.
Mapping the Dog Genome
The dog genome has 39 pairs of chromosomes, humans by comparison have 23 pairs. There are some 25,000 genes in the dog genome and scientists had to sequence around 2.4 billion ‘letter’s of DNA code. The work was carried out by the Broad Institute of MIT and Harvard.
Understanding the dog genome and comparing it with the human genome should help us to learn more about the genetic basis of many diseases that afflict humans. We share many genes with our animal chums and also many disorders. Like us dogs can become afflicted with various cancers such as skin cancer and bone cancer.
About the Research
When scientists go on the hunt for cancer genes in dogs, they are looking for specific genetic markers. These are small DNA sequences that differ between dogs, and their chromosomal locations are known about. If these markers are consistently seen in dogs with cancer and not in healthy dogs, it gives a strong hint that there is a cancer gene nearby.
This sort of genetics research is also carried out in humans, but what makes the dog so valuable is that to carry out effective and meaningful research you need to have generations of afflicted families and a wide DNA sample set. Dogs have shorter generations and many more offspring than humans and so are ideal subjects for this kind of research.
One early success to come out of the Dog Genome Project was the discovery of a gene for kidney cancer. Analysis of the DNA from a pedigree of German Shepherd dogs found the gene on chromosome 5. Scientists then looked at a comparable chromosomal region in humans and found a gene that had been recently implicated in causing cancer of the kidney.
Looking for specific genes in dogs should also be much easier than looking for genes in humans. Although the dog has been domesticated for thousands of years, many breeds are only a few hundred years old. Their genomes have not been subject to the kind of evolutionary shuffling of the deck that happens in many older species. Large sections of their DNA should be the same.
Benefits for Dogs
The genetics research into dog and human genomes will also benefit our pampered pooches. Once disease genes are located, they could be
treated i.e. silenced or removed when the technology is up to it. Or they could be bred out of the population.