If you can remember back to high school biology class, you may recall learning about a monk who studied pea plants – Gregor Mendel, often considered the father of modern genetics. Mendel discovered through selective breeding of pea plants that two pea plants could pass on traits to their offspring that they themselves didn’t express. He found that some genes are dominant over other recessive genes. In his experiments some yellow podded pea plants produced green podded pea plant offspring. This sounds simple, yet it is actually quite profound. When a plant, or animal, mates each parent gives a “package of genes” to the offspring, some of these genes are dominant and some are recessive. Recessive genes can cause hidden traits. When each parent gives the same recessive gene to the offspring, the hidden trait appears. If, on the other hand, one parent plant gives a dominate gene and the other gives a recessive, only the dominate trait will appear, but the recessive can still be passed onto future generations. These same principles apply to dogs.
Here’s a basic Punnett square showing two parent dogs: both are carriers (have a dominate normal retina gene and a silent recessive PRA (progressive retinal atrophy) gene). Because both parents have a dominate gene for normal retinas, they themselves will have normal retinas. When these dogs are bred statistically 3⁄4 of the puppies will have normal eyes since they will each receive at least one dominate gene for normal retinas, however, the other 1⁄4 of their puppies will receive two copies of the recessive gene for PRA and will likely become blind sometime during their adult lives. Basically, if at least one parent tests clear (has two copies of the dominate good gene), all of the puppies will have normal vision. By DNA testing our parent dogs, we ensure that no goldendoodle puppy will receive two copies of a recessive gene that could result in an unwanted health problem.
DNA testing doesn’t hurt our goldendoodles. We collect DNA via a buccal swab (cheek swab) and then send the swab to Spokane, Washington. Paw Print Genetics conducts tests on the DNA samples and notifies us of the results. You can visit our page on Paw Print Genetics’ website to view our dogs’ results for yourself. They also have lots of information about genetic testing if you want to learn more about it.