In mice, a diet low in protein during gestation and lactation in mice alters gene expression of leptin, a hormone involved in metabolism.
And if the metabolic syndrome, including obesity, diabetes and hypertension, was partly due to what the mother eats during pregnancy? Far from being absurd, this finding is gaining ground over the past ten years: epidemiological studies have shown that the intrauterine environment, particularly the maternal diet, participated in this syndrome in adult men. Had to find biological evidence of the link between these disorders and maternal nutrition. Biologists from the Unit of Human Nutrition, Clermont-Ferrand, the Institute of the brain and spinal cord and the Cochin Institute in Paris have obtained in mice.
Biologists have submitted pregnant mice either a normal diet (a diet containing 22 percent protein) or a low-protein diet (10 percent protein). Small have “suffered” regimes of their mother the first day of gestation until weaning, and they received a normal diet. Reached adulthood, the offspring whose mothers had a low protein diet have a metabolic paradox: they have a lower weight than mice “normal”, but they eat more than they.
These metabolic abnormalities due to maternal deprivation involve protein leptin, a hormone that contributes to a balanced diet by controlling energy metabolism and appetite. Biologists have studied the leptin gene of the offspring: in mice whose mothers were on a diet low in protein, regions (or developers) before the genes are part of “demethylated”, that is to say that some do not wear methyl chemical group, unlike the corresponding regions of normal mice. But the promoter regulates the expression of the gene for leptin. An “adaptation” has therefore metabolic development in individuals lacking protein during gestation until weaning.
This so-called epigenetic modification disrupts the normal expression of the gene for leptin and metabolic control of mice. Thus, a difference in maternal diet may result in changes in gene expression of the small, but that the genes are mutated (this is indeed a chemical change – the addition of a methyl group – which changes gene expression, whereas the sequence of elements of the DNA is not changed). The long-term consequences are detrimental in this case, and could be transmitted to offspring, but the latter remains to be seen.