Born the world’s first puppies, conceived by in vitro fertilization – BBC

In February 2013, scientists from Cornell University (NY, USA) reported , the puppy named Klondike – a cross between a Labrador retriever and beagle – reached the age of nine months and his health It does not raise any concerns. The importance of this report was the fact that

Klondike was the first dog that came into being as a result of replanting frozen embryos surrogate mother.

The biological mother of the Klondike – female beagle – scientists fertilized by means of artificial insemination, ie the introduction of the father’s sperm Labrador in her body. Then removed from the body beagle embryos and freeze them, and then transplanted into the body of a surrogate mother – also a beagle. The embryo is successfully caught, bringing to light a Klondike. Biologists call it achieving a breakthrough in the science of “reproductive processes are substantially different from the dog breeding other mammals, – commented lead author Alex Travis. – We are working to understand what exactly are these differences – then it will be possible not only to the development of oral contraceptive for dogs, but also the ability to control reproduction of the canine in order to save endangered species ».

On the night of 9 on December 10, 2015 the magazine PLoS ONE published the article , which tells about another research group reaching the Alex Travis. At this time

scientists were able to successfully carry out the dog in vitro fertilization procedure – first attempts to do so have been taken back in 1970, but success still could not be crowned.

In vitro fertilization – is assisted reproductive technology, which is used in case of infertility. During IVF egg extracted from the woman’s body, fertilized in the laboratory (in vitro), then the resulting embryo is contained in a hatchery, where it begins its development, and then transplanted into a woman’s body, which bears a child.

The effectiveness of IVF, even if people are not very high: the probability of survival of the embryo is affected by many factors, and it may vary from 20 to 50%, so do a single embryo transfer procedure is rarely obtained. In addition, the ECO is fraught with many pitfalls: often a child is born prematurely, the likelihood of developing a variety of malformations of the gastrointestinal tract is increased about 4 times, defects in the atrial or ventricular septal heart occur 2.1 times more frequently, as “hare lip” – 2.4 times more likely than in the case of a natural pregnancy.

However, if the technique of in vitro fertilization of people have worked, in the case of dogs, the situation was quite different. The first difficulty arose at an early stage of the work: the scientists had to take a mature egg in the female body. First, researchers took eggs have reached the same degree of cell differentiation, which is the case with other animals.

However, the reproductive cycle of the dogs is not like the cycles of other mammals, and fertilize the egg did not work. Empirically it has been found that egg must be taken from the body for usual day later – after fertilization began to occur in a much greater number of occasions.

In the second stage of the scientists waited another problem . After the sperm of the male dog enters the body of the female, he is “ready” to fertilize it. Researchers have to simulate the same conditions in a laboratory. Co-author Jennifer Nagashima and Skylar Sylvest understood that this cell culture is necessary to add magnesium. Under its influence the sperm reaches the desired state, after which the procedure of fertilization became succeeds in 80-90% of cases.

After fertilization and embryo formation had to freeze them – but here the scientists already had experience. Biologists have used the same technology that a few years ago in the case of the Klondike. As a result of

19 embryos were puppies podsazheny into the body of the female beagle, seven of them settled down and in due course came to light. Biological parents of five puppies – beagle, two others are a cross between a mother and a father-beagle-labrador.

Now the age of the dog is seven weeks, they are absolutely healthy. According to the study authors, their success is extremely important from a practical point of view. Development of methods for in vitro fertilization dogs could save from extinction certain types of canine: the representatives of this family are extremely susceptible to genetic diseases.

Dogs suffer from some 350 hereditary diseases – almost twice as much than the number of genetic diseases that infect other mammalian species.

Scientists hope that in the future using the methods of genetic editing, they will be able to eliminate these diseases is still at the embryonic development of animals, and then transplanted healthy embryos already in the mother’s body. This will not only save from extinction of some species of canids, but also to make certain breeds of dogs healthier Thus, Labrador Retriever can be rid of predisposition to lymphoma and Dalmatians – from kidney stones.