How Studying Dog DNA Helps Scientists Understand Human Disease
This series is brought to you by our partner, Purina ONE®. These stories share the innovations that are changing how we care for and learn from our pets. Read more about how pets—and the people who love them—can brighten lives and strengthen our communities at the GOOD Pets hub.
If you were challenged with unlocking the secrets of hereditary disease in humans, you would probably look first to your parents for insight into your family’s health history.
But why not also look at your family pet?
Dogs have roughly the same number of genes as humans and share nearly 400 hereditary diseases with us. This is why scientists studying human health can benefit from the research tools that have been developed in canine genomics — the study of the structure and function of dog DNA — and genetics. With so many similar genes and health issues shared between dogs and humans, medical researchers now have a new tool, the canine genome, for uncovering the biology behind certain diseases in humans. For example, the studies of epilepsy, retinal disease, Type 1 Diabetes, and prostate cancer have been advanced by this new way of looking at correlations between humans and dogs.
“Genomics has allowed a paradigm shift in the way science is done,” says Steven Hannah, Director of Molecular Nutrition at Purina. “When I was a student, a scientist might hypothesize how one protein is involved in a biological process and spend an entire career conducting research around that single protein. But since scientists can now monitor the expression of the entire genome, we can let the cells tell us what biological adaptations they are making in response to changes in their environment.”
A key innovation in this type of study is Purina’s recent development of what’s called a global canine gene-expression microarray — described by Hannah as a “fancy microscope slide.” Before microarrays existed, scientists could only study one gene at a time. Now they can examine the expression of thousands of genes at once.
In living things, “gene expression” refers to the cellular process of turning the information found on DNA into functional proteins such as hormones, enzymes or cell signals — the “machines” that actually do biological work within the body.
So why is this technology considered to be a scientific breakthrough? Since they can now observe 30,000 canine genes at the same time, researchers are able to observe how cells are changing in response to things such as exercise, health issues or specific nutrients.
This can help determine which specific genes (or sequences) are involved in these processes, adding a completely new layer of evidence beyond the symptoms and diseases that your dog’s veterinarian might diagnose. Simply put, it’s not just confirming what is occurring, it’s also helping to answer why.
But the ability to analyze thousands of genes in a single pass has created another challenge: what to do with the mountains of data.
Bioinformatics— a field that uses computer programs to store, organize, and analyze huge amounts of biological data— now lets researchers interpret the biological significance of gene-expression changes over time within the microarray. Without bioinformatics, it would be impossible to see if nutrition affects the expression of specific genes — for instance, monitoring the ways omega-3 fatty acids can help control inflammation within the body.
“We’re rapidly moving towards a day when we’ll be able to examine the genomes of both dogs and humans, and assess risk factors that both have, and what you can do early in life nutritionally to proactively maximize your health,” Hannah says.
At Purina and elsewhere, many studies are currently being conducted using canine microarrays. As more genomic tools and genetic tests are developed for both dogs and humans, future generations will be able to gain a deeper understanding of their own genomes. This understanding could lead to customized lifestyles, behaviors and nutrition that promote ongoing health and longevity, allowing people and their pets to enjoy longer, more fulfilling lives together.
Illustration by Stacia Burtis