DNA FOR TODAY AND TOMORROW

DNA certification allows owners to uniquely identify their dogs, ending all questions about identity and parentage. Each dog tested is assigned a "DNA profile number" specific to that AKC-registered dog. Correlating directly to that number is a genetic constitution (called a genotype) that provides absolute identity of the dog using 10 pairs of genes.

These 10 gene pairs, which have nothing to do with conformation or health, can be used to verify the parentage of a litter. All that is required is the genotype of the sire, dam and pup. Using capital letters to represent genes and identifying the pairs from left to right, we can examine three Bloodhounds: the sire, the dam and one pup (see the diagram, over)

At every gene Pair (called a locus; the plural is loci and is pronounced "lo-sigh"), the pup, Anastasia, received one member of each pair of genes from the sire, Bruno, and the other member front the dam, Contessa. Note that each genotype is unique. Parentage can be easily verified for Anastasia, since, mathematically speaking, no other purebred Bloodhound has her genotype, and no other combination of sire and dam could have produced a pup with her unique genotype.

In the AKC's DNA Certification Program, owners get a "Certificate of DNA Analysis" for their records (see image above). Listed on each certificate is the dog's unique genotype, representing the 10 pairs of genes. When a breeder has genotypes on file for the sire and dam of a litter, the resulting puppy genotypes are unique and consistent only with that sire and dam. That is why DNA certification guarantees parentage, and that is why there is great interest in the program.

By certifying only the sire and the dam, breeders can realistically eliminate all concerns about parentage: All the new puppy owner has to do is to obtain the genotype for the pup, and it will show that the genotype of the pup was uniquely determined at conception by combining 10 genes from the sire and 10 from the dam. (Scientific purists require that we say one member of each of the 10 pairs is from the sire and the other from the dam.)

Examine the "Certificate of DNA Analysis" for the DNA profile number and the genotype. The profile number will appear on all future registration documents and is uniquely tied to the dog's genotype. After Oct. 1, 1998, the AKC Board of Directors made DNA certification required for males whose semen is collected for shipment or storage (i.e., frozen semen to be stored or fresh-chilled to be shipped). The purpose of this decision, of course, is to guarantee parentage when the male is physically separated from the breeding process. The reception to the announcement of this requirement has been overwhelmingly positive. And Just for the record, a DNA profile is good forever - at a cost of only $40.

When registration papers fail the DNA parentage verification tests at inspected kennels, litters are canceled and AKC privileges are withdrawn.

In addition, the Parent Breed Club Program is in the process of collecting DNA samples, on a voluntary basis, at 35 national specialties in 1998. Furthermore, the Parent Breed Club Program has been invited by 56 additional breed clubs to collect samples in 1999 and 2000.

On an individual basis, every owner and breeder can now elect to help support the AKC in its mission to guarantee the integrity of the registry. "DNA Registered" is taking on a new meaning, and the opportunities to focus on breeding better dogs have never been greater.

USING DNA TO VERIFY PARENTAGE

THE AA BB CC's of DNA

Purebred dogs represent a true celebration of genetic variation. Careful selection by mankind throughout the centuries has resulted in genetic diversity within dogs that is unprecedented in any other mammalian species. Although there is still a long way to go before scientists fully understand the complexities of the canine genome, they are well underway. And as scientists come to know more about canine genetics, the results will likely be interesting, important and probably surprising.

All breeds have the same genes, as well as a finite number of gene pairs. Although there is some speculation about the exact number, it is estimated that dogs possess between 50, 000 and 100, 000 gene pairs in every cell. Variations of these gene pairs, called "alleles, " exist for every gene pair. Alleles account for the differences between Chihuahuas, Saint Bernards, and all breeds in between.

A dog's genetic constitution, called a genotype,"can be determined by an analysis of a simple bristle swab swirled against the inside cheek portion of a dog's mouth. For example, a possible analysis for a dog taking part in the AKCs Voluntary DNA Certification Program, which tests for 10 gene pairs, might read: BD/CE/DD/DZ/EG/CC/GH/CD/CF/AA. Each letter represents one member of a pair of genes, and each gene pair is represented by two capital letters.

For example, "AA" means that on a specific chromosome pair, one chromosome has "A" at a specific site or "locus" and the other member of that pair has an identical "A" allele or gene. Remember, dogs have 78 chromosomes (38 pairs + XX in females and 38 pairs + XY in males) and these are numbered 1 through 38, plus the X and Y chromosomes.

Why, then, test only 10 gene pairs? Because each of the 39 chromosome pairs contains 50,000 to 100,000 gene pairs, it is impossible, prohibitively expensive and unnecessary to test thousands. It has been determined that testing 10 gene pairs distributed randomly across the 39 chromosome pairs is mathematically sufficient to establish a unique identity.

Among different breeds there are different gene frequencies, which means that specific alleles occur more or less frequently than others. One of the goals of the Parent Breed Club Program is to understand these frequencies using 17 markers and, therefore, learn how to efficiently structure tests for parentage across different breeds. These results will permit the AKC to establish a program based on extensive knowledge of the genetic markers used across all breeds. No one has ever collected and analyzed this amount and kind of genetic variation in purebred dogs. The results will undoubtedly provide useful information to the fancy and to the scientific community.

This shuffling of genetic information is responsible for both the successes and the failures as new pups are whelped. Without genetic variation, no new combinations would result and the genetic challenge of producing better dogs - by carefully selecting and breeding the best to the best - in succeeding generations would not be a reality.

What does all this mean for breeders? It means that we can now begin traveling down a long road - a road that begins with the absolute identification of each dog by DNA, and continues with foolproof parentage verification. It follows that the AKC registry will have absolute integrity. That fact closes the doors to possible questions about the registry, and permits fanciers to focus on what the sport is really all about -breeding better dogs.