Elaine Ostrander, PhD; Fred Hutchinson
Cancer Research Center
Richard McCombie, PhD, Cold Spring Harbor Laboratory
The
dog genome project is a collaborative study involving scientists at the University
of California, the University of Oregon,
and the Fred Hutchinson Cancer
Research Center aimed at producing a map of all
of the chromosomes in dogs, which can be used to map the genes causing disease and those genes controlling morphology and
behavior. By initially identifying the correct and healthy sequence of genes,
the disease-causing genetic mutations are more easily identified. This, in turn,
will assist them in understanding how they respond to treatments, and therefore discover the best treatment for the disease. A successful example: the difference in breast cancer types can be determined by genetic
expressions. Treatments have been changed depending on genotype vs. phenotype.
As of September 2003, sequencing the Canine Genome
Mapping is approximately halfway done. Expected completion is estimated for the
spring of 2004. It is known that all canines have 38 pairs of chromosomes, plus
the X and Y sex chromosomes. So far there are 3,270 markers to 3,009 unique positions. There are 900 genes and ESTs (Expressed Sequence Tags) mapped so far. Mapping completion will help researchers tremendously in moving forward in their research. The 1st dog sequenced was a Standard Poodle. Researchers
have compared the dog to the human and have been able to find comparisons within the sequencing to each. This sequence revealed that 18,473 dog genes have human equivalents.
This had already surpassed the 18,311 known at the time from the mouse sequence.
They also found genes related to a dog’s life: dogs have many more
genes that are linked to smell than people do.
Moving ahead, and determined to sequence the most
inbred dog they could find, the Boxer was chosen. They discovered the Boxer to
have 1 sequence: 20,000 and 1 sequence variant: 1,000. There is a large range
of variation in heterozygosity with a 4-fold range between breeds.
To date, scientists have sequenced the human, mouse,
rat and worm species. The completion of the chimpanzee sequence occurred in the
fall of 2003. The dog genome project represents an important addition to the
comparative genomics database. For instance, the top 10 diseases among purebred
dogs include several that afflict humans, such as cancer, epilepsy, heart disease, allergy, retinal disease and cataracts.
Further, the dog has long been studied by pharmaceutical companies and academic institutions as an important physiological
model and has aided the development of life-saving, bone marrow transplant techniques.
The dog genome sequencing project was approved in
April 2003. Sequencing began in June 2003 and expected to be completed in the
period of March – May of 2004. The sequence will then be compared to small
amounts of sequence from 10-20 other breeds, including the beagle, to study genetic variation within the canine species, as
well as compared to the human, cat, rat, etc. by Matthew Breen.
Samples are acquired
from cheek swabs for mapping, but blood samples are necessary for disease research.
AWS Partners’ recommended resources:
Cold
Spring Harbor Laboratory
http://www.cshl.org
The Dog Genome Project
http://mendel.berkeley.edu/dog.html
The Fred
Hutchinson Cancer Research Center:
Dog Genome Project
http://www.fhcrc.org/science/dog_genome/
AVMA: New Method Yields
a Glimpse at Canine Genome
http://www.avma.org/onlnews/javma/nov03/031115i.asp
Dog Genome Unveiled
http://www.nature.com/nsu/030922/030922-17.html
