Molecular Biology

Molecular Genetics

Dog Genome Sequence; Analysis Sheds Light On Human Disease; Differences Among Canine Breeds

Researchers Publish Dog Genome Sequence; Analysis Sheds Light On Human Disease; Differences Among Canine Breeds: "While dogs occupy a special place in human hearts, they also sit at a key branch point, relative to humans, in the evolutionary tree. It was already known that humans share more of their ancestral DNA with dogs than with mice; the availability of the dog genome sequence has allowed researchers to describe a common set of genetic elements -- representing about 5 percent of the human genome -- that are preferentially preserved among human, dog and mouse. Rather than being evenly distributed, some of these elements are crowded around just a small fraction of the genes in the genome. Future studies of these clusters may give scientists the critical insight needed to unravel how genomes work.

The international team of researchers also identified roughly 2.5 million single nucleotide polymorphisms (SNPs) sprinkled throughout the dog genome. SNPs are variations in the DNA code, some of which contribute to diseases or the overall health of a dog. SNPs also can be used to create a set of coordinates with which to survey genetic changes, both within and across dog breeds. These efforts revealed that individual breeds have maintained a large amount of genetic variability, despite their long history of restrictive breeding. In practical terms, this means that future efforts to locate disease genes in dogs can be much narrower in scope than comparable human studies, requiring a smaller number of genetic markers and DNA samples collected from the blood or cheek from only a few hundred dogs."

. . . developing since 10/06/06