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Posted by on Oct 1, 2012 in Science |

ENCODE, Correction: If there junk DNA in the genome

ENCODE, Correction: If there junk DNA in the genome

A few days ago I wrote a post about the fabulous project in which he asserted that there is no junk DNA. After reviewing many articles I edit writing. The junk DNA exists.

The ENCODE project has been a huge research effort in which large areas have been studied in the human genome. The project has produced more than 30 articles in leading scientific journals. The sequencing of the human in 2001 taught us the sequence of all 3 billion letters (nitrogen bases) that make up our genome. We had the book but did not know it meant. ENCODE has been working to understand its meaning, ie what do these DNA sequences, which are important for the body.

ENCODE is a job I do not want to read . It’s like a list of the parts of a Boing. Only the engineer who has to work with them using it. It is an entertaining story. It is however a monumental project and essential.

The problem is that the sale of the project is bad and tabloid media and confusing many publications in the world starting with The Wall Street Journal or Wired and coming to this humble editor. Although this time it’s not just a problem of the press. Scientists themselves are responsible as Ewan Birney, one of the leading scientists of the project.

The problem round around the term junk DNA (junk) . Let’s start by saying it is very unfortunate since its inception decades ago. A small portion of DNA are genes which produce proteins, ie encoding DNA. the rest is non-coding DNA .

A portion of the antisense DNA is very important since it regulates the expression of genes. The rest of the non-coding DNA is a huge amount yet. Somewhere we do not know quite what to do. Another part is knowing that one junk DNA.

We know it because part junk DNA consists of long chains called transposons, mobile elements recognizable self-replicating and inactivated virus remnants and genes that are no longer functional.

And above all is the comparison of the genomes of different living things. One would expect that the greater complexity, greater genome, but not always. Onions show a huge variety of sizes in its genome, from 7-31 pg (picograms). By contrast, the man is only 3.5 pg. That is, similar species have very different genomes and smaller species have large genomes.

On the basis of the confusion is the concept function handled by any of the ENCODE team members. Functional as they are doing something. RNA encoding for example. That has biochemical functionality. But that does not mean you have biological functionality. The functional biochemical junk DNA produces no change in the organism, does not affect phenotype. Just do not bother in the genome and endures for generations.

I hope this is helpful rectification. Genetics is a very complex and exciting field that continues to produce results and news. It is a key science S. XXI. We will continue to watch.

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