Reply #56: Right. Keep an open mind, and new tools make new research possible.

[azul]

My background is in pharmacology and toxicology, and this new field of knowledge of genetic controls opening up suggests that many many chemicals will have to be re-screened for these more subtle effects. And it looks like these control changes from what we eat and are exposed to at critical times are passed on to grandchildren.



Obesity, Epigenetics, and Gene Regulation


Our genome contains all the information to make us who we are, but many of the details of our behavior and appearance are actually determined by gene regulation.

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Environmental Triggers

A number of environmental triggers have been shown to affect the behavior of an organism's epigenome, tipping the balance between methylation or lack thereof, and thus between genes that are "off" and those that are "on." One suspected trigger is a chemical found in many plastic drink bottles, including baby bottles, called bisphenol A. In one particularly notable study, scientist Randy Jirtle and his group of researchers exposed pregnant mice to bisphenol A and watched as more of their genetically identical progeny developed into yellow, obese mice than would normally be expected (Dolinoy et al., 2007). In Jirtle's experiment, DNA methylation at the agouti gene sites was decreased by 31%. (DNA methylation was reduced on other genes as well.) These results supported the hypothesis that bisphenol A alters the action of organisms' epigenomes by removing methyl groups from DNA.

http://www.nature.com/scitable/topicpage/Obesity-Epigenetics-and-Gene-Regulation-927