Mary C. Wakeman, D.V.M.
Ashford Animal Clinic
Canine Fertility Center
269 Mansfield Road
Ashford, CT
860-429-2110

Freezing Canine Ovarian Tissue
Samples for Cloning


Yes, we can freeze your bitch's ovaries.

Freezing ovaries is less difficult than freezing canine semen.

Yes, eggs can be matured from frozen ovaries. Not all the time, and not by everybody. Not necessarily from the samples we have frozen.

Here's the situation in a nutshell. The world at large thinks that there is a 'canine over-population problem'. This being the case, very little funding ever goes into research which would allow the Dog Fancy and Ethical Dog Breeders to catch up to the world of sheep, cattle, horses, and homo saps. Imagine the response of PETA, were the AKC to fund a graduate student at the University of Georgia, where Dr. Richard Fayrer-Hoskins has what is essentially the only academic research program with emphasis on canines. So, when your local or breed club starts handing out money to the Baker Institute and other institutions, to pay for a graduate student's room and board for a year, whether or not anything of real benefit to dogs is likely to result, you might think about mentioning the canine reproductive program at the University of Georgia. With techniques for collecting mature eggs, fertilizing them in vitro, implantation in a host dam, all worked out in great detail and done routinely for other species, the steps between the freezing of semen and ova, and the production of normal healthy offspring should fall in place very quickly once there is a program for this research funded. So, it's up to us as breeders and exhibitors to think about advancing this knowledge base.

At the other end of the country, at the San Diego Zoo, Dr. Barbara Durrant has been developing an endangered canid program, which engages in freezing semen and ovaries of endangered canid species, among other things. Zoo researchers, working with the group at the U. of GA, have successfully matured ova from these frozen ovaries.

So, we can freeze ovaries at this time. We do this at the Canine Fertility Center in Ashford, CT. What we can't do is guarantee that a given frozen sample will reliably result in ova which may be matured and fertilisable at some future date. However, the technique - while fussy - is still no more difficult than freezing canine sperm, which we can do very reliably. In the case of ovarian tissue, since the skills for maturing the eggs from the frozen ovarian tissue are only available in a couple of places, we can't test these samples to see if they can produce suitable ova.

How do we get the ovaries? They are taken at the time of spaying, or as part of a euthanasia process. These are then transported as quickly as possible to the freezing center, in the appropriate solution and at the appropriate temperature.

The freezing is done according to Dr. Durrant's protocol, and the ovaries are stored in liquid nitrogen tanks, just as the semen is.

The AKC does not have a program for overseeing the record keeping as regards this process, or for sanctioning breedings from banked ovarian tissue.

We at the Canine Fertility Center are a CLONE semen bank. We have undertaken to keep genetic material, ranging from blood clots through tissue samples and cheek mucosal brushes (the same way cells are obtained for DNA certification) for our clients for some years. Our record keeping and storage conditions are the same as we use for frozen semen. The objective is to have all our ducks in a row should the AKC get to the point of recognizing the efforts of early practitioners of this technique. We keep the records just as they specify for frozen semen. However, we cannot give you any certainty as to when the AKC will consider sanctioning such sample banking, and if, when they do, they will apply their sanction retroactively to banks which keep samples as we do. We can only say, that we are keeping records appropriately, and are processing and storing the tissues in what we understand to be the best manner available at this time.

 

Samples for Cloning

Samples including other tissues (somatic tissues) such as blood clots (the portion of the blood sample left after the serum has been removed), other body tissue specimens, and cheek swabs, will not be of any use for breeding puppies. Rather they are kept to provide material for further DNA analyses, or even for cloning at some future date, should these techniques become available. Those of us who have very small amounts of semen frozen on a great dog might think seriously about the best use of that semen; is it best to use it to try to impregante a bitch, or for genetic testing, or for cloning. Note: clones can't be developed from an egg or a sperm cell. However, semen also contains some epithelial cells and some white blood cells from the donor and these have the complete genetic material.

Please understand that the techniques discussed above - maturing ova from frozen ovarian tissue, in-vitro fertilisation, and cloning companion animals - are not yet available for us to try. The point to taking these tissues and preserving them is very much one of nothing ventured, nothing gained.

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