First puppies born by in vitro fertilisation

In a major breakthrough, researchers at Cornell University in the US successfully used in vitro fertilisation technique on a dog that resulted in the birth of a litter of puppies.

Nineteen embryos were transferred to the host female dog, that 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.

"Since the mid-1970s, people have been trying to do this in a dog and have been unsuccessful," said Alex Travis from Cornell's college of veterinary medicine.

For successful in vitro fertilization, researchers must fertilise a mature egg with a sperm in a lab, to produce an embryo. They must then return the embryo into a host female at the right time in her reproductive cycle.

The breakthrough opens the door for conserving endangered canid species, using gene-editing technologies to eradicate heritable diseases in dogs and for study of genetic diseases.A

Canines share more than 350 similar heritable disorders and traits with humans, almost twice the number as any other species.

"We can freeze and bank sperm, and use it for artificial insemination. We can also freeze oocytes, but in the absence of in vitro fertilisation, we couldn't use them. Now we can use this technique to conserve the genetics of endangered species," Travis said.

In vitro fertilisation allows conservationists to store semen and eggs and bring their genes back into the gene pool in captive populations.A

In addition to endangered species, this can also be used to preserve rare breeds of show and working dogs.

The study appeared online in the journal Public Library of Science ONE.