The test-tube puppies with Nagashima & Songsesen
WORLD's FIRST TEST-TUBE PUPPIES
Rarely is a major scientific breakthrough so darn cute. Researchers at the Cornell University in New York and the Smithsonian Institution in Washington announced this week (Dec 2015) the world's first test-tube puppies born by in vitro fertilisation (IVF) on July 10, 2015 in the US. The study is published in the science journal PLOS ONE. Jennifer Nagashima and Nucharin Songsesen are the authors.
The surrogate hound gave birth to seven puppies which are a mix of beagle, labrador and cocker spaniel. IVF efforts with dogs failed all these decades as it is an extremely difficult exercise in dogs unlike in the case of humans.
This huge scientific breakthrough could prove useful in everything from conserving endangered species to removing 'deleterious traits from breeds' using gene-editing technology, with research potentially applicable to 'models for human disease' as well. Canines share more than 350 heritable diseases and traits with humans, almost twice the number as any other species.
Dr. T. Rama Prasad,
'Pay what you can' Clinic, Perundurai, Erode Dt., TN, India., Former Medical Superintendent (Special), RTS & IRT Perundurai Medical College and Research Centre.
'Pay what you can' Clinic, Perundurai, Erode Dt., TN, India., Former Medical Superintendent (Special), RTS & IRT Perundurai Medical College and Research Centre.
7 Bundles Of Scientific Joy: 'Test Tube Puppies' Prove IVF Can Work In Dogs
Mike Carroll/Cornell University College of Veterinary Medicine
Jeffrey MacMillan/Cornell University
Seven tussling puppies could bring a smile to anyone's face. But one litter has a team of scientists beaming more than usual.
The puppies — five beagles and two "bockers," or beagle-cocker spaniel mixes — are the first ever born through in vitro fertilization.
IVF has been used successfully in other animals — including, notably, humans — for decades. But despite numerous attempts, scientists had never succeeded in using IVF in dogs.
But this year, researchers at Cornell transferred 19 embryos into a female host dog. In July, after a scheduled cesarean section, they welcomed seven new puppies into the world.
They described the breakthrough in a paper published Wednesday in Plos One.
As NPR's Rob Stein reported earlier this year, dogs have successfully been cloned before: In fact, for a cool $100,000, you can have your own pet dog cloned. But where cloning involves transferring one dog's existing DNA into a donor egg, IVF involves the creation of a new genome through fertilization, so each animal has a unique set of DNA.
Mike Carroll/Cornell University
Previous attempts to use IVF in dogs had resulted in very low rates of fertilization, and no live births at all after IVF embryos were transferred to a host.
There are numerous reasons why, the Cornell scientists explain in their paper.
First, female dogs only ovulate once or twice a year. And their eggs appear dark under a light microscope — which makes it harder to see the structures inside of the egg, the scientists note. The eggs are also released before they're fully matured.
The Cornell researchers found that if they waited an extra day, compared to IVF procedures for other mammals, before extracting eggs, success was more likely. Adding magnesium to the environment where the sperm and egg met also helped with fertilization, the team found.
Once they had successfully created embryos, the scientists froze them until the host dog was ready to become pregnant — a key part of overcoming the difficulty of timing IVF, given how few times a year a dog can get pregnant, a Cornell press release notes.
Then, for the first time, the scientists saw IVF puppies carried to term.
The seven surviving puppies are genetically the offspring of two different fathers (a cocker spaniel and a beagle) and three different beagle mothers, carried by the same beagle host.
The achievement could eventually help endangered canine species, the scientists say: Frozen eggs and sperm from "genetically valuable individuals" could be used to continue to create offspring after the animals themselves have died.
And there are also implications for disease research, the scientists say. Successful IVF procedures will allow scientists to more efficiently explore gene editing in dogs, which could help eradicate inherited diseases.
Dogs get spontaneous cancer, like humans do, and pet dogs are exposed to many of the same environmental factors as humans, the scientists note. Overall, they say, dogs share more than 350 disorders or traits with humans — almost twice the number as any other species — so advancing research into canine disease could ultimately help treat humans.
But first the scientists had to master canine IVF. And the success was a joyful one, as one co-author of the paper told The Guardian:
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