Australian Shepherd Health & Genetics Institute

Australian Shepherd Health & Genetics Institute

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DNA Parentage Verification


What is DNA parentage verification?

It uses a set of DNA markers to establish that an individual is the offspring of a particular male and female by verifying that the offspring has a set of markers that reflect potential contributions of markers from the two parents.  Example (deliberately simplified):  If the male had markers A-A, B-B, and C-C and the female had D-D, B-B, E-E, the offspring would have to be A-D, B-B, and C-E.  Any other combination would exclude it as an offspring of one or both parents.

  Is it the same as DNA fingerprinting?

The process used is the same.  A “DNA fingerprint” is a set of markers unique to that particular individual.  Marker sets are also what is used in the parentage verification process.

 Can DNA testing be used to identify parents when the dog’s background isn’t known?

Theoretically.  You might be able to identify a dog’s unknown parents this way but practically it may not be possible.  Both of the dog’s parents would have to be in a parentage verification registry (usually operated by or for studbook registries).  That registry would have to offer a service that would allow you to collect a sample from your unknown dog and submit it to them for comparison to dogs already in the registry.  Both the dog’s parents would have to be in the same registry.  (Different registries use different marker sets.)  If only one of the parents is in the registry they would not be able to match it to the unknown-background dog because there is no way to verify which marker came from a particular parent if tother parent’s set isn’t available.

Can DNA tell the offspring of two brothers apart?

Sometimes.  If the dam(s) have been profiled along with both males it is possible to do so IF the two brother’s marker sets differ sufficiently.  Closely related animals, particularly from inbred or linebred pedigrees, can have very similar DNA and therefore the marker setes might be very similar.  Sometimes additional markers may need to be used to determine parentage.

How is DNA used to determine parentage on multi-sire litters?

Because each sire will generally have a different profile, though closely related sires might prove problematic.  Provided that complication is avoided, results will indicate which pup was sired by which dog.  Multi-sire litters can maximize the production potential of a high-quality brood bitch.  However, you should make sure that the studbook registry the dogs are listed with allows it and, if they do, make sure you follow whatever rules apply to multi-sire litters.

How accurate is DNA parentage verification?

Far more accurate than blood typing ever was, which is why human paternity testing is now done with DNA and why DNA evidence is so frequently used in court cases.

Does it matter what organization you use for DNA parentage verification? 

Any of the extant DNA parentage verification programs or even a private DNA lab can develop a DNA profile on your dog.  They can all verify parentage if the parents and offspring are all profiled.  However, it does matter where the dogs have been profiled.

Work done by direct arrangement with a private lab is useful only for your own purposes.  It will not be accepted by a registry’s program.  Studbook registries that have DNA parentage verification programs will only recognize dogs profiled through their own program.  This applies even if you pay the same lab they use to do the work.  Where dogs hold dual registrations it may be necessary to profile the dog with each registry’s program.

If owners can submit their samples directly to the registry’s DNA program , how can anyone be sure they are submitting  the right dog?

Someone intent on cheating can just as easily present the wrong dog to a vet who is asked to collect the sample as send one in himself.  However, unlike using a dog of the same breed, color and gender for standard screening exams, pulling a switch in a DNA parentage verification program is going to backfire as soon as offspring of that dog are entered into the program.

If you send in Shep’s sample and say that it’s Oso’s, when you breed Oso and someone profiles one of his offspring it isn’t going to match.  You won’t be able to use Oso, ever, because his pups will never match “his” profile unless you always substitute Shep to do the actual breeding.  Likewise, Shep could never be used under his own name because he couldn’t be profiled or the ruse would be uncovered.  If you didn’t profile him all his puppies would come back as “Oso’s” so what’s the point?  If a registry requires that all breeding stock be profiled, falsification is impossible.

Can DNA profiling validate that two dogs are the grandparents of a third dog based on DNA samples from these three dogs alone?

If those three dogs are the only available relatives, the answer is no.  You don’t know what marker alleles either parent had, nor the other two grandparents.  Even if you have one grandparent from each side of the pedigree, you can’t confirm or exclude them with any degree of confidence because you don’t know what the other grandparents’ markers were.

Realizing that there could be instances when a parent’s DNA might not be available, ASCA did establish a rule (Registry rules section 2.2.3) whereby  a single unavailable parent’s profile can be determined with about 90% probability.  It requires that eight offspring of the unavailable dog be profiled, along with the mate or mates with which those offspring were produced.  The rule also allows for other combinations of closely related dogs to be used, so long as a 90% probability is achieved.

At best it requires testing a whole batch of dogs.  In the scenario you describe you’d need a lot more than just those two grandparents tested before you could prove parentage on your subject dog.

What are the advantages of DNA profiling?

For the breeder, it provides uncontestable proof that the litters he produced are by the stated parents.  For the registry it reveals registration errors and unrecognized mis-matches (male dogs can be sneaky) and prevents fraud.

When errors are found, what happens?

That depends on the rules of that particular registry.  It is technically possible to correct some errors – as when another male breeds a bitch unbeknownst to the breeder.  Note:  wrongly assigned parentage can happen through no fault or knowledge of the breeder if someone else allows the dog access to the bitch or when the dogs are particularly determined and clever.  Aussies are known for both.

Is it possible to prove two dogs are littermates with their DNA?

DNA can’t tell you whether dogs are littermates, but it can indicate whether they are full siblings.  However, without having the parents’ profiles you can’t be completely sure. If the dogs’ markers show very little difference it is an indication that they may be full siblings but it isn’t conclusive proof.

Can the DNA sent for parentage verification be saved and used for other things like health research?

Probably not.  The information generated by the ID/parentage verification process is not useful for disease research.  Registries usually use swabs or whole blood for sample collection.  Swabs generally don’t hold enough material left to store and are discarded after use.  Even if DNA was left over, the “shelf life” of used swabs is limited.  Left over blood, if stored, might be useful but it would depend on the registry’s willingness to let it go for other purposes.

DNA banking programs, like that of OFA’s Canine Health Information Center (CHIC), which are known by researchers and have gathered large numbers of samples from many breeds along with associated health data are invaluable resources for health research.   They will accept swabs but advise that blood provides the better source of DNA for storage.