SAN FRANCISCO — A gene that has been linked to obesity and diabetes when inherited from mom prevents body cells from absorbing enough sugar from the bloodstream, research suggests.A recent, unpublished study shows that a gene that’s active only when inherited from an individual’s mother plays a key role in regulating blood sugar. Muting the gene’s activity in mouse cells grown in lab dishes caused a tenfold improvement in the cells’ ability to take in the sugar glucose, according to a study presented Monday, June 9, in San Francisco at the Beyond Genome conference. The gene, called Atp10c, could help explain why obesity and diabetes so often go hand in hand, says lead researcher Madhu Dhar, a molecular geneticist at the University of Tennessee in Knoxville. In previous work, mice with a single copy of the gene inherited from their mothers had up to twice as much fat tissue as mice without an active copy of the gene. The obese mice also had high blood sugar and poor sensitivity to insulin — the hallmarks of diabetes. If inherited from the father, the same gene will not affect blood sugar because a process called imprinting silences the gene, Dhar explains. “This gene may have some impact on obesity” in people, comments Nagaraja Ganachari-Mallappa, a molecular biologist at Texas A&M University’s Scott and White Hospital in Temple. In a 2001 study of people with a brain disorder caused by a gene that sits next to Atp10c on the chromosome, scientists noticed that patients who had inherited the segment of DNA containing both genes from their mothers had abnormally high body weight.The next step is to look at obesity and diabetes patients and determine how many of them carry the maternally inherited gene, Dhar says.