DNA May Carry a Memory of Your Living Conditions From Childhood

An anonymous reader writes "Canadian and British scientists have found that how rich your family was when you were a kid — as judged by wealth, housing conditions and occupation of parents — has a huge impact on your current DNA. 'This is the first time we've been able to make the link between the economics of early life and the biochemistry of DNA,' says Moshe Szyf, professor of pharmacology at McGill University. The study did not show whether the DNA changes identified are passed on to offspring, but if so, repeat cycles of poverty could be putting poor children at a serious disadvantage for heart disease, diabetes and lung disorders."

Comments

Methylation

[Hatta]

The changes in DNA are due to methylation of the DNA, not changes in sequence. This can lead to more or less of a given gene being expressed, but won't lead to any actual changes in the genes.

Re:Methylation

[ZiggyM]

According to wikipedia on cell reprogramming, these gene expression changes are erased from offspring: "After fertilization the paternal and maternal genomes are once again demethylated and remethylated (except for differentially methylated regions associated with imprinted genes). This reprogramming is likely required for totipotency of the newly formed embryo and erasure of acquired epigenetic changes." See http://en.wikipedia.org/wiki/Reprogramming

Re:Methylation

[joocemann]

Nature, Sep 29 2011.

Scientists show that the protein, Tet3, is responsible of wiping of the male pronucleus methylation patterns after fusion between sperm and egg.

http://www.nature.com/nature/journal/v477/n7366/full/nature10443.html

As for the maternal DNA, demethylation, as far as I know, is unknown but occurs as well.

I'm curious if the disease that arises from these poor conditions is related to epigenetic changes that IMPRINT (are not demethylated, and thus passed through generations). As many are finding out, epigenetics are much more intricate and important than previously conceived.

Re:May be an advantage, not a burden?

[Derek Pomery]

Yep. From TFA.

============
The study did not show:

        specific disease effects linked to these areas of DNA methylation differences
        or indeed whether there were positive or protective effects
        or whether these changes might be passed on to offspring.

The study was not designed to look at these areas.
============

I imagine the answer is even that "it depends"

Presumably extreme poverty to the point of malnutrition would be more harmful than positive.

Yes....

[RobinEggs]

Yes, but changes in fundamental sequence aren't the only way genes 'change'. Changes in expression constitute almost all of the biological changes that affect to an organism during its lifetime, as opposed to merely affecting its offspring; it's only because of expression changes that you ever go from a fetus to an adult (or from a fetus to a slightly larger fetus, for that matter).

I mean, presumably you understand this, unless you're able to talk about methylation solely from reading the article, but I don't want anyone to get the impression that 'only' changing the way DNA is expressed is a small feat.

Expression is *everything*. Almost nothing can be accomplished in any eukaryotic organism without deliberate changes in expression like this; basal transcription (the rate at which your genes are used entirely because the right parts randomly came together with nothing else - like methylation - helping or preventing them) accomplishes almost nothing.

The human genome is a lot like a computer in that way: almost nothing happens without something specifically telling it to work, and these guys just discovered a whole damn code library.

Re:So...what's the answer?

[geekoid]

Fail.

Poverty is the state of one who lacks a certain amount of material possessions Absolute poverty or destitution is inability to afford basic human needs, which commonly includes clean and fresh water, nutrition, health care, education, clothing and shelter. About 1.7 billion people are estimated to live in absolute poverty today. Relative poverty refers to lacking a usual or socially acceptable level of resources or income as compared with others within a society or country.