Jaime Pellicer y el mayor genoma secuenciado

Jaume and the Giant Genome

Japanese canopy plant (Paris japonica)

He found that the canopy plant genome had 150 billion base pairs—50 times as many as human DNA. If the DNA in a human cell were unraveled, it would stretch to two meters. A strand of DNA in the canopy plant would span 100 meters. 

In fact, in humans, only about 1.5 percent of the genome’s DNA codes for proteins. In the Japanese canopy plant the percentage is sure to be even less. The function of that surplus DNA—or even whether there is a function—is a hotly debated mystery and will likely remain so until the species is sequenced. 

Noncoding sequences used to go by the derogatory names “selfish” or “junk” DNA, but have more recently acquired milder tags, including “transposable elements” or “jumping genes.” Unless somehow restrained, these proliferate across genomes like weeds. One sequence, called Alu, has copied itself a million times and makes up some 10 percent of the human genome.

There is, however, some evidence that the canopy plant, despite—or perhaps because of—its huge genome, maintains a competitive edge over plants that share its mountain habitat. In the chilly months of early spring, while neighboring competitors sit dormant, and before overhead trees come into leaf, the plant gets a jump-start on growth by pumping its cells full of water. This cellular expansion allows the canopy plant to increase its size and soak up more sunlight before DNA replication and cell division occur in the warmer summer months.


Read more: Jaume and the Giant Genome - The Scientist - Magazine of the Life Sciences http://www.the-scientist.com/article/display/57932/#ixzz1DOJgSbet