Yellow mice are more susceptible to obesity, diabetes and cancer than their brown spotted siblings. Image: Duke University Medical Center
Reading Food supplements such as folic acid can protect unborn children from harmful environmental chemicals. The close American researchers from feeding experiments with pregnant mice. For example, the chemical bisphenol A (BPA), which occurs in food packaging, led to changes in the genetic material of mouse embryos. The vitamin folic acid and the phytochemical genistein were able to counteract these negative influences. Bisphenol A is a constituent of polycarbonate resins found in many packaging, including baby bottles. To test what effect the substance has on unborn children, the researchers fed mice with BPA. The amounts were chosen so low that they had no direct harmful effect on the animals. However, the BPA in the feed meant that significantly more animals with yellow fur were born. As other studies with mice of the same strain show, yellow animals are at greater risk for diabetes, obesity and cancer.

Like BPA, folic acid can affect the coat color of mice. This is shown by earlier studies by the research team. In another series of experiments, the researchers now both BPA and folic acid in the feed. The result: The vitamin was able to counteract the effects of BPA, so that the mice were born neither too many yellow nor too many brown animals. Genistein, an ingredient of soybean, had a similar effect.

Although the yellow mice look different than their brown spotted siblings, they show no difference in the sequence of their DNA building blocks. Rather, there are significantly more so-called methyl groups on the DNA strand of brown spotted mice. These chemical switch molecules block a gene responsible for the yellow coat color and thus affect the appearance of mouse children? a form of inheritance called epigenetics. BPA decreases the number of chemical switches and folic acid increases it again, which is reflected in the opposite effect of the two substances on the coat color.

However, the results of the animal experiments can not be readily transferred to humans. So researchers can not yet tell what amounts of BPA in human embryos lead to epigenetic change. The same applies to the optimal dose of folic acid or genistein. Randy Jirtle, one of the researchers, warns that excessive levels of genistein could also be harmful. display

Dana Dolinoy (Duke University in Durham) et al .: PNAS, online pre-publication, DOI: 10.1073_pnas.0703739104 ddp / science.de? Larissa Kessner

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