<The San Jose Mercury News

MARYLAND



Studies suggest greater number of human genes

Two scientific papers published this week suggest that there might be many more human genes than thought, or at least that the human genome has hidden levels of complexity that are only starting to be revealed.

Both papers report that human cells make far more RNA, a counterpart of the genetic material DNA, than can be accounted for by the estimated 30,000 to 40,000 human genes.

The presence of RNA is often thought to indicate the presence of an active gene. But the papers, one in the journal Science and the other by Johns Hopkins University researchers in Nature Biotechnology, suggest that a lot of RNA is being made from DNA that is not part of known genes.



This, combined with recent discoveries that human beings are apparently doing a lot more with a lot fewer genes than anyone thought we had (Estimate: 100,000. Actual: about 30,000) leads me to believe that the way genetics operates is one heck of a lot more complicated than anyone thinks.

Up until now, everyone saw genes as sort of a binary code: this particular combination on a string did this particular thing. It's beginning to look like there's a lot of parallel processing going on, maybe some analog sneaking in the side door, or perhaps processes we don't even have a clue about.

What this does mean is that radical genetic engineering has to be approached very carefully. We are not talking about a string of beads any more, but a pile of pickup sticks. Fixing a gene linked to a particular disease might louse up something that would have seemed totally unrelated in a simple genetics coding.