Longevity Shown for First Time to Be Inherited via a Non-DNA Mechanism

[n2doc]

By Sarah Fecht | October 19, 2011 | 2



In October 2009 Stanford University geneticist Anne Brunet was sitting in her office when graduate student Eric Greer came to her with a slightly heretical question. Brunet's lab had recently learned that they could lengthen a worm's lifetime by manipulating levels of an enzyme called SET2. "What if extending a worm's lifetime using SET2 can affect the life span of its descendants, even if the descendants have normal amounts of the enzyme?" he asked.

The question was unorthodox, Brunet says, "because it touches upon the Lamarckian idea that you can inherit acquired traits, which biologists have believed false for years." The biologist Jean-Baptiste Lamarck theorized in 1809 that the traits exhibited by an organism during its lifetime were augmented in its offspring; a giraffe that regularly stretched its neck to eat would father calves whose necks were longer. The idea was largely discredited by Darwin's theory of evolution, first published in 1859. More recently, scientists have begun to realize that an organism's behavior and environment may indeed influence the genes it passes to its offspring. The heritability of those acquired traits is not based on DNA, but on alterations in the molecular packaging that surrounds a gene. When Greer approached Brunet in 2009 with his question about worms and SET2, such "epigenetic" inheritance had only been discovered for simple traits such as eye color, flower symmetry and coat color.

Brunet and Greer went ahead with the experiment. The results, published October 19 in Nature, provide the first evidence that some aspects of longevity can be passed from parent to offspring, independent of DNA's direct influence. (Scientific American is part of Nature Publishing Group.)

"I think this is a fundamentally important finding," says Matt Kaeberlein of the University of Washington in Seattle, who studies molecular mechanisms of aging. "It demonstrates for the first time that aging can be influenced by epigenetic changes that occurred in prior generations."


more

http://www.scientificamerican.com/article.cfm?id=longevity-inheritance-epigenetics

[Kurmudgeon]

1. Ah, so Darwin wasn't perfect, imagine that....

[DCKit]

2. Geez, just how much was one 19th century scientist supposed to accomplish in a single lifetime? nt

[trotsky]

7. I was not aware that anyone ever said he was.

Well, straw men usually put up by right wing fundies have, I suppose.

[azul]

3. We've sequenced the genome and are getting to know what it codes for,

but you would kinda think the controls are where the action is at, and that this is where we should be putting the big efforts.

This is where the most productive jobs are at, the most return in terms of health and sustainability for the investment.

[bleever]

4. Kick so I can find this tomorrow and look up Arthur Koestler's book

that talks about the backlash against Lamarckian theory encountered by a scientist studying toads.


ed: word that makes it opposite of what I meant.

[bleever]

9. "The Case of the Midwife Toad", 1971.

An examination of the work of Paul Kammerer on the heritability of acquired traits, and the difficulties encountered in going against the accepted orthodoxy of science.

[eridani]

5. There is a sense in which Aristotle's laws of motion are correct

Check out Stoke's Law. That Lamack is right in some greatly narrowed meaning of heredity is the same kind of intellectual phenomenon.

[sofa king]

6. Isn't that interesting?

As I find myself glossing the article so that I can better understand it, I find myself coming to the analogy of a re-gifted Christmas present: sometimes, some of the tape from the previous wrapping is also passed on to the next fruitcake owner. The package can be damaged in re-gifting, and that tape from a previous re-gifter can still play an important structural role in the overall integrity of the box. It can even make it stronger than it originally was, in which case the tape is less likely to be removed the next time it is re-gifted.

It's hardly Lamarckian. In fact, not too long ago this trait suite would be indistinguishable from other DNA-coded heritable traits. DNA itself is useless without a vast array of other proteins and enzymes to read it and manufacture other coding, messaging, and structural compounds. But it's still pretty cool.

[Ready4Change]

8. Is this kind of like 'soft genes?'

Can this work backwards? In other words, if an organism develops a VERY useful trait in it's molecular packaging, can that result in a change in either it's own DNA or in it's offspring? Could this be a mechanism for an organism to adapt it's genes to it's environment in a more targeted way? In a way that is more reliably useful than random errors?