Inheriting Traits, not Genes

Turns out, yet again, that genetics is more complicated than we once thought.

According to new research... well, read on:
 The findings, published online today in Nature, present a modern-day version of Lamarckian inheritance, in which acquired characteristics can be passed to offspring without changes to the genetic code.

Marks of Methuselah: Glowing regions show chemical marks on the genome ofC. elegans identical to those in ancestors with life-span-increasing mutations—even though this descendant lacks the mutation.
Travis J. Maures

BIOMEDICINE

Worm Offspring Inherit Longevity Even without the Genes

Worms given life-span-enhancing mutations produce offspring that lack the responsible genes but live longer anyway.

• THURSDAY, OCTOBER 20, 2011
• BY SHARON BEGLEY

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Although much more research remains to be done, the new study raises the tantalizing possibility that if Grandma practiced caloric restriction—which affects the expression of longevity-enhancing genes—her descendants might reap the benefits.

The inheritance occurs through "epigenetics": alterations not in the coding sequence of DNA (those ubiquitous A's, T's, C's, and G's) but in chemical changes that affect whether genes are expressed. One such change involves histones, proteins that act as spools for a cell's long strands of DNA. Some of the best-known longevity genes, those belonging to the Sir2 family, make proteins that alter histones.

The tiny soil-dwelling worms C. elegans, when given mutations that make them live longer, transmit that trait even when their progeny don't inherit the life-extending mutations. 

In the new work, Brunet's graduate student,Eric Greer, blocked the three key proteins that make up the ASH-2 complex by mutating their genes. As expected, the worms lived longer—typically, an extra seven days beyond their lab life span of 20. Then Greer bred the mutated worms with normal worms until their descendants no longer had the mutations. Nevertheless, the progeny still lived longer, as did their own descendants: even though their genes for the key proteins were normal, an epigenetic memory of longevity persisted. As a result, their DNA was coiled up tight, and their suspected aging genes were sidelined.

This is also interesting in my believe that pretty soon we are going to see significant changes in the human lifespan, above and beyond our current biological limit. It seems that you might be able to pass the traits on simply by practicing (or therapy) which extends the normal lifespan.