Although the search for heritability was successful in yeast, finding missing heritability in humans is far more complicated, Kruglyak said. For example, interactions between genes can contribute to heritable traits, but such interactions are difficult to detect with genome-wide association studies (GWAS), which are the primary means by which geneticists look for DNA variations associated with diseases or traits. In addition, environmental factors such as nutrition also can influence gene activity, and these influences can be elusive to the genome-wide study. GWAS also may be inadequate at detecting common DNA spelling errors that have only small effects, or it may fail to find DNA variations that have a large effect but are rare.
The study sheds light on the role of nature (genetic factors) versus nurture (environmental factors) in determining traits and disease risk, according to Bert Vogelstein, director of the Ludwig Center at the Johns Hopkins University School of Medicine and a Howard Hughes Medical Institute Investigator.
"The nature versus nurture argument has been brewing for decades, both among scientists and the lay public, and 'missing heritability' has been problematic for the 'nature' component," said Vogelstein, who was not involved in the Princeton study.
"This beautiful study demonstrates that the genetic basis for heritability (nature) can be precisely defined if extensive, well-controlled experiments can be performed," Vogelstein said. "Though the results were obtained in a model organism, I would be surprised if they didn't apply, at least in part, to higher organisms, including humans."
Kruglyak said that one approach to finding the missing heritability in humans might be to apply genome-wide scans to large families, rather
|Contact: Morgan Kelly|