By Jason Arunn Murugesu
Thurtell/Getty Images
Genetic analysis of the Australian labradoodle reveals that most of its genes come from the poodle, highlighting how small differences in genomes can result in new distinct breeds.
In the 1980s, a concerted effort began to produce a guide dog with a reduced likelihood of triggering allergic reactions in humans. The result is the Australian labradoodle – a cross between a Labrador retriever and a standard poodle, which doesn’t shed much hair that can trigger an allergic response.
“Australian labradoodles are one of the most popular designer-breeds in the United States,” says Elaine Ostrander at the US National Institutes of Health. “I see three of them on my street alone. Labradors are smart and trainable, but there is a big desire to have dogs that elicit a low allergy response.”
Advertisement
For 30 years, the Australian labradoodle has been selectively bred to establish a population that could be recognised as a true breed rather than a mix. Now, Ostrander and her colleagues have explored how this 30-year-long programme of selective breeding has influenced the Australian labradoodle’s genetics.
They analysed the DNA of 21 Australian labradoodles, and compared this with DNA from purebred Labradors and poodles. The researchers also examined DNA from so-called first-generation labradoodles – which are simply the offspring of any cross between a Labrador and a poodle.
The team looked at over 150,000 random points in the dogs’ genomes and compared them with each other. Unsurprisingly, first-generation labradoodles were a 50:50 mix between Labrador and poodle DNA. But after 30 years of breeding, the Australian labradoodle’s genome is composed nearly entirely of poodle DNA.
They also found that Australian labradoodles had a higher than expected frequency of gene variants related to the dog’s coat. These findings suggest that the genes for a poodle’s coat, which breeders presumably wanted to dominate, have dragged large portions of the rest of the poodle’s chromosomes into the labradoodle along with it.
“The study of the genetics of dog breeds is important because it helps to identify the level of diversity remaining within breeds, and enables specific mutations underlying inherited disease to be located,” says Sarah Blott at the University of Nottingham.
“This information is useful to breeders, enabling them to select matings which reduce the risk of inherited disease in puppies.”
Journal reference: PLoS Genetics, DOI: 10.1371/journal.pgen.1008956
More on these topics:
