A new study in conservation biology at the University of Illinois, headed by Animal Biology professor and department head Dr. Ken Paige, indicates that loss of genetic diversity in a few key genes may influence levels of activity in a broad variety of other genes, causing significant changes in biological mechanisms dealing with metabolism, stress and defense. These changes shunt energy away from reproduction and undermine some basic cellular functions, resulting in the syndrome commonly called Inbreeding Depression.
This study, carried out with six inbred strains of the fruit fly Drosophila melanogaster, is ground-breaking, and has produced results that will undoubtedly result in further and more detailed studies. Of great interest was the fact that 75% of reproductive declines in the inbred fruit flies were attributable to loss of dominant alleles and consequent unmasking of recessive alleles, while 25% were attributable to loss of "overdominance" or heterozygote superiority effects. (Both of these problems were highlighted in J. Jeffrey Bragg's 1996 brief to the Canadian Kennel Club, "Purebred Dog Breeds into the Twenty-First Century.") Identical changes were found in 46 separate genes in fruit fly culture lines showing high levels of inbreeding depression, creating a good basis for further research.
Inbreeding depression is thought to be a major cause of weakness and genetic disease in purebred dog breeds, as well as being of major concern to conservation biologists in their efforts to preserve dwindling wildlife populations.
Researchers take first look at the genetic dynamics of inbreeding depression
Posted by ditkoofseppala at April 12, 2009 02:08 PM