title: Methyl donor supplementation prevents transgenerational amplification of obesity.
abstract: BACKGROUND
  The obesity epidemic, recognized in developed nations for decades, is now a worldwide phenomenon. All age groups are affected, including women of childbearing age, fueling concern that maternal obesity before and during pregnancy and lactation impairs developmental establishment of body weight regulatory mechanisms in the fetus or infant, causing transgenerational amplification of obesity prevalence and severity. The biological mechanisms underlying such processes remain unknown.
  
  
  METHODS
  We used agouti viable yellow (A(vy)) mice to test the hypothesis that maternal obesity induces transgenerational amplification of obesity. We passed the A(vy) allele through three generations of A(vy)/a females and assessed cumulative effects on coat color and body weight. By studying two separate but contemporaneous populations of mice, one provided a standard diet and the other a methyl-supplemented diet that induces DNA hypermethylation during development, we tested whether potential transgenerational effects on body weight might be mediated by alterations in epigenetic mechanisms including DNA methylation.
  
  
  RESULTS
  The genetic tendency for obesity in A(vy) mice was progressively exacerbated when the A(vy) allele was passed through successive generations of obese A(vy) females. This transgenerational amplification of body weight was prevented by a promethylation dietary supplement. Importantly, the effect of methyl supplementation on body weight was independent of epigenetic changes at the A(vy) locus, indicating this model may have direct relevance to human transgenerational obesity.
  
  
  CONCLUSIONS
  Our results show that in a population with a genetic tendency for obesity, effects of maternal obesity accumulate over successive generations to shift the population distribution toward increased adult body weight, and suggest that epigenetic mechanisms are involved in this process.
authors.affiliation: Department of Pediatrics, Baylor College of Medicine, USDA Children's Nutrition Research Center, Houston, TX 77030, USA. waterland@bcm.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Waterland
authors.forename: M
authors.initials: M
authors.lastname: Travisano
authors.forename: K G
authors.initials: KG
authors.lastname: Tahiliani
authors.forename: M T
authors.initials: MT
authors.lastname: Rached
authors.forename: S
authors.initials: S
authors.lastname: Mirza
mesh_terms: D054366:Agouti Signaling Protein / Q000235:genetics; D000818:Animals; D001835:Body Weight / Q000235:genetics; D019175:DNA Methylation; D019587:Dietary Supplements; D004195:Disease Models, Animal; D044127:Epigenesis, Genetic; D005260:Female; D005784:Gene Amplification; D020022:Genetic Predisposition to Disease; D008297:Male; D051379:Mice; D008820:Mice, Obese; D009765:Obesity / Q000235:genetics* / Q000517:prevention & control
chemical_list: D054366:Agouti Signaling Protein; C515183:a protein, mouse