Long before the science of genetics was sufficiently advanced to comprehend the nature of inheritance (let alone map the genome of an entire organism), dogs were bred for specific characteristics and capabilities. As a result there is a great deal of morphological diversity within the Canis familiaris species, observable in the 400 modern dog breeds. Certain breeds contend with high incidences of particular diseases such as cancer, cataracts, epilepsy and diabetes (Broad Institute 2008). This variation can be used to assist in the investigation of which genes are linked to the development of numerous diseases. According to the researchers at the Broad Institute who mapped the genome of a female boxer (Tasha, see right), the distinct differences between breeds makes the genetic dissection of their characteristic diseases “more tractable in dogs than in humans” (Nature 2005). Thus the mapping of the dog genome will add to the ever-increasing knowledge base of genes which are associated with particular diseases.
In addition to mapping the dog genome, researchers compared the data to other mammals including humans and mice. A number of interesting findings were made, some of which are likely to have wide-ranging implications for our understanding of mammal evolution. As an illustration, human and dog lineages have certain sets of functionally related genes which show very similar patterns of evolution (Nature, 2005). Previous investigations comparing the human to only the mouse led researchers to believe that innovations in brain development, for example, were human-specific. Since a similar level of evolutionary acceleration has now been inferred in Canis familiaris, researchers have achieved a new insight into the close correlation humans and other mammals.
List of References
Broad Institute 2008, Dog genome sequencing project, http://www.broad.mit.edu/mammals/dog
Lovgren, Stefan 2005, Dog genome mapped, shows similarities to humans, ‘National Geographic News’, http://news.nationalgeographic.com/news/2005/12/1207_051207_dog_genome.html
Nature 2005, ‘Genome sequence, comparative analysis and haplotype structure of the domestic dog’ vol. 438, pp. 803-819 (8 December 2005) http://www.nature.com/nature/journal/v438/n7069/full/nature04338.html
Photo taken from National Center for Biotechnology Information 2009, Dog genome resources, http://www.ncbi.nlm.nih.gov/genome/guide/dog/
