Gene Swapping VS Gene Theft (1/30/2007)

Researchers at Rice University have created a mathematical model that argues that evolution doesn't proceed solely through breeding and genetic mutations. The theory suggests that organisms also swap large sections of DNA.

Michael Deem, the John W. Cox Professor in Biochemical and Genetic Engineering and a professor of physics and astronomy at Rice, is the author of the study which tries to explain one of the enduring mysteries of evolution, namely its seemingly accelerating rate of change, sometimes called spontaneous genetic mutation.

The principal factor in this acceleration is a process Deem calls horizontal gene transfer (HGT). In HGT, an organism will give or exchange large chunks of its own genetic material to organism in a process that can be described as a naturally occurring gene graft.

Proteins produced by the native genetic code of an organism allow the organism to accept and graft the new genes into its own genome.

Many HGT insertions, like most genetic mutations, will have no impact on the development of a species, and some transfers will cause harmful effects. A small percentage of the transfers, however, will lead to sudden, beneficial changes in an organism's genome.

The new mathematical model created by Deem and professor Jeong-Man Park simulates how beneficial HGT insertions propagate across a species.

Thinking about HGT, I wonder if it may work in another fashion, specifically genetic theft. In this process, the genetic code is sampled by the recipient, and is taken from the host organism.

The main reason I believe this motivator is more likely is that it isn't in the host organisms benefit to give away its genetic material. Your DNA is your code, and allowing another organism access to it, potentially opens you up for attack.

Taking genetic information from another organism may give the recipient organism the ability to synthesize the host organizms proteins easier. This may allow the recipient to eat the host without any ill effects, or subdue it without harm to itself. The process is probably hit or miss, with more misses than hits.

In any case, I don't disregard Dr. Deem's research, I think his research will clearly show that gene's are being transferred, I just question the way in which they are being transferred. The next stage of research should focus on finding the mechanism that is allowing it to occur.

DNA is replicated during cell division, and mistakes often occur, sometimes to good effects sometimes to bad effects. Our DNA has a safe guard against this, in a gene called p53. This gene is responsible for telling the cell to commit suicide if a genetic defect is found during transcription.

Almost all cancers are caused by the suppression of gene p53, which means even though the cell has a defect, it will continue to replicate. In fact, when the gene is forcefully reactivated, cancers tend to shrink and die off.

Perhaps p53, or a related gene working in conjunction allow some DNA to be changed, appended too or removed altogether without tripping the deadman switch.

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