Hidden Link in DNA of Plant

There is first evidence that an organism's "epigenetic" code - an extra layer of biochemical instructions in DNA - can evolve more quickly than the genetic code. Thus, it can strongly influence biological traits. This breakthrough was reported in the September 2011 issue of the journal Science.

"Our study shows that it's not all in the genes," said Joseph Ecker, a professor in Salk's Plant Molecular and Cellular Biology Laboratory, who led the research team. "We found that these plants have an epigenetic code that's more flexible and influential than we imagined. There is clearly a component of heritability that we don't fully understand. It's possible that we humans have a similarly active epigenetic mechanism that controls our biological characteristics and gets passed down to our children. "

Ecker and colleagues traced these patterns to chemical markers that serve as a layer of genetic control on top of the DNA sequence. "Perception of the extent of epigenetic variation in plants from generation to generation varies widely within our scientific community," said Robert Schmitz, a post-doctoral research in Eckers' laboratory and the lead author on the paper. "We actually did the experiment, and found that overall there is very little change between each generation, but spontaneous epimutations do exist in populations and arise at a rate much higher than the DNA mutation rate, and at times they had a powerful influence over how certain genes were expressed."

See Salk's press release at http://www.salk.edu/news/pressrelease_details.php?press_id=516