Researchers from the Monell Center in Philadelphia have published in the online journal BMC Genetics a study that counts 6,000 genes as involved in increasing body weight.
Monell behavioral geneticist Michael G. Tordoff, PhD, an author on the study, said, "Our results suggest that each newly discovered gene is just one of the many thousands that influence body weight, so a quick fix to the obesity problem is unlikely."
The Monell researchers identified the 6,000 genes by analyzing the body weights of knockout mouse strains at the Jackson Laboratory Mouse Genome Database. Knockout mice have a specific gene that is inactivated to allow researchers to determine the function of that lacking gene and how it causes disease.
A third of the knockout mice surveyed were found to weigh less, which indicates that the missing genes contribute to heavier body weight. The researchers then extrapolated the total number of genes in the mouse genome to get the number of genes that influence body weight.
Tordoff said: "It is interesting that there are 10 times more genes that increase body weight than decrease it, which might help explain why it is easier to gain weight than to lose it."
