Buried within the DNA of each and every individual is a special DNA
signature that can be used to uniquely identify that individual. DNA profiling
is the name given to the technique that has been developed to reveal this
DNA signature. Initially, DNA-based approaches to identifying individuals
were pioneered in humans, but the same technology has easily been transposed
to the dog. Nowadays, special sequences found in DNA called microsatellites
are used to build up this DNA signature. Microsatellites have become the
system of choice for DNA profiling and genetic testing in humans. The US
Armed Forces, FBI, Scotland Yard, The Royal Canadian Mounted Police and
multiple forensic laboratories use microsatellites for their forensic,
paternity and individual identification tests. The reasons that have made
them come to the fore in humans are the very reasons that currently make
them the system of choice for dogs.
The technique essentially involves preparing a DNA sample from an individual
dog. For this we need to obtain some tissue from the dog in order to prepare
the DNA. The ideal source of material would be a blood sample which will
permit us to isolate DNA from the white cells; this however requires a
vet to take the sample of blood before passing it onto the laboratory for
testing. Less invasive techniques which don’t require veterinary intervention
have therefore been sought to make the procedure more convenient.
One alternative source of tissue are the cells that can be easily removed
from the inside of a dog’s cheek, called buccal cells.
In this case all that is required is to gently rub a small plastic
brush against the inside of the cheek to remove the buccal cells. The brush,
containing the cells can then be returned to the laboratory for analysis.
DNA can be made from both tissue sources, although considerably less DNA
is provided by the buccal cells because they
are considerably fewer in number.
Once isolated, the DNA can then be treated to reveal the individual-specific
DNA signature. Several laboratories throughout the world have been using
this technique successfully for a number of years. Many of you will
have read in the dog press of the American Kennel Club’s pilot study on
DNA profiling which has recently been concluded. This particular study
used the microsatellite-based DNA profiling that we intend to use on the
Staffordshire Bull Terrier pilot study.
What can DNA profiling offer? Well, as I have explained, the DNA signature
that is revealed can uniquely identify an individual dog. However, the
profile is not just a means of identification because it also carries within
it information on the parents of the dog. This is because a puppy inherits
half of its DNA from its mother and the remaining half from its father.
This essentially means that half of the components that make up the profile
are maternal in origin and the other half paternal. So it is in these two
areas that profiling has impact: individual identification and parentage
verification.
IDENTIFICATION: The DNA profile is the ultimate
in individual identification and offers a ‘tamper-proof’ means of identity.
The profile need only be produced once and the DNA sample used to produce
it can be stored as a permanent DNA record throughout the dog’s life. Identification
could be essential in a number of instances. For example, the availability
of a profile could be used to identify an animal that may have been lost
or stolen, and subsequently recovered. The profile could also be used to
check the authenticity of a DNA sample being
used to screen for the presence of disease-causing genes. Many such tests
are being developed and it would be invaluable to be able to verify that
the correct dog’s DNA is being tested for the presence of the deleterious
gene. Repeating the DNA profile on the same sample of DNA being used to
carry out the gene test would be straightforward and prove conclusively
that the correct animal is being tested.
PARENTAGE/PEDIGREE ANALYSIS Provided that
the DNA profiles of both parents are available, pups in a litter can be
profiled and their profiles checked with their parents’ profile to verify
that the correct parents have been registered. This will ultimately have
commercial value in that it puts a premium on those litters that have been
analysed by DNA profiling.
Profiling costs £15 per sample, and this amount is payable on
submission of samples.
Details on methods of payment will be included in the sampling kit.
You can order your kit by contacting The Kennel Club, Clarges Street,
Piccadilly, London or on line at www.kennelclub.cog.uk
Other companies providing this service include Rosgen (UK's leading
provider in services of animal DNA analysis) Introductory Offer costs £30.00
per test. This is the discount price but it does include VAT