Cornell scientists create first litter of puppies through in vitro fertilization

Cornell Scientists used in vitro fertilization to create a litter of puppies, a development that could help advance genetic research and animal conservation.--Courtesy of Cornell University

They say that good things come in small packages, and in the case of the latest breakthrough in animal science, the old adage rings true. Cornell University researchers produced the first litter of puppies through in vitro fertilization, a development that could hold big implications for animal conservation and studying genetic diseases.

The latest findings offer a "powerful tool for understanding the genetic basis of diseases," Alex Travis, associate professor of reproductive biology at Cornell, said in a statement. "With a combination of gene editing techniques and IVF, we can potentially prevent genetic disease before it starts," Travis said.

The research also holds promise for wildlife conservation. Cornell scientists froze the embryos before artificially inseminating them into the female dog, allowing researchers to insert them at the right time in the dog's reproductive cycle. The technique could be used to preserve endangered species and rare breeds of dogs by holding onto their genes and introducing them later in captive populations. Travis and his team published their findings in a recent issue of Public Library of Science ONE.

To create the IVF litter, scientists transferred 19 embryos to a host female dog that gave birth to 7 healthy puppies: two from a beagle mother and a cocker spaniel father and 5 from two pairings of beagle fathers and mothers.

But Cornell researchers faced a few obstacles along the way. Female dogs have different reproductive cycles than other mammals, so some of the dogs' eggs did not fertilize right away. And sperm preparation was difficult because scientists had to simulate the conditions of the reproductive tract.

The team addressed both of those challenges head-on, leaving the egg in the female dog's oviduct a day longer to improve the odds of fertilization and adding magnesium to a cell culture to help prep the sperm for insemination. After scientists made the changes, fertilization rates jumped to 80% to 90%, Travis said.

Cornell scientists aren't the only ones exploring in vitro technology for animal health. Colorado State University researchers recently used IVF and artificial insemination to create a herd of American bison that are free of brucellosis, a disease endemic to Yellowstone National Park. Last month, the herd was set free in the Soapstone Prairie Natural Area, marking the first time in 150 years that the species entered the region.

- read the statement