The first ever litter of puppies conceived through in vitro fertilisation has been unveiled by scientists.
The technique, developed by a team at Cornell University in Ithaca, New York, could help save endangered species, preserve rare breeds of dogs and remove inherited diseases.
Nineteen embryos were placed into a host female dog, which gave birth to seven healthy puppies, two from a beagle mother and a cocker spaniel father, and five from two pairings of beagle fathers and mothers.
Dogs share more than 350 similar heritable disorders and traits with humans, almost twice the number as any other species.
Associate professor of reproductive biology, Alex Travis, said: “Since the mid-1970s, people have been trying to do this in a dog and have been unsuccessful.”
For successful in vitro fertilization, a mature egg must be fertilized with a sperm in a lab, to produce an embryo. The embryo must then be returned to a host female at the right time in her reproductive cycle.
The first challenge the team the Baker Institute for Animal Health at Cornell faced was to collect mature eggs from the female oviduct.
Through experimentation Jennifer Nagashima and colleagues found if they left the egg in the oviduct one more day, the eggs reached a stage where fertilization was greatly improved.
The findings have wide implications for wildlife conservation because in vitro fertilization allows conservationists to store semen and eggs and bring their genes back into the gene pool in captive populations.
In addition to endangered species, this can also be used to preserve rare breeds of show and working dogs.
With new genome editing techniques, researchers may one day remove genetic diseases and traits in an embryo, ridding dogs of heritable diseases.
While selecting for desired traits, inbreeding has also led to detrimental genetic baggage.
“With a combination of gene editing techniques and IVF, we can potentially prevent genetic disease before it starts,” Travis said.
Since dogs and humans share so many diseases, dogs now offer a “powerful tool for understanding the genetic basis of diseases.”