Is the Central Dogma Dead Yet?

The Central Dogma of Genetics is the belief, formulated by Francis Crick, that information flows from DNA strand to DNA strand in replication, and from DNA to proteins in transcription and translation, but that it never flows from the environment into DNA or from protein to protein. Explanations of the central dogma are always accompanied by illustrations like this. These explanations are also accompanied by assurances like this one, from the textbook by Hartl and Jones (1998)

"The term 'dogma' means a set of beliefs. The term dates from when the idea was first advanced as a theory; since then, the 'dogma' has been confirmed experimentally, but the term persists"

Above all else, we are assured, the central dogma is not a dogma in the religious sense. It is very well confirmed...

except it isn't at all. Well, proponents of the central dogma admit, we know retrovirus rewrite DNA. And the cell has all sorts of mechanisms to correct mutations. And prions allow information to flow from protein to protein.

Now from the journal Nature is a report of a new mechanism for mutation correction. This one does not require a copy of the normal gene to be present in the cell. Here is the NYT report. This is the write up from Nature's website. This is where you can access the full article if you subscibe. (Not working for me.) So there we have it, another big way that information flows into the genome.

Actually, the central dogma functions very much like a dogma. For starters, people cling to it, even though the exceptions mount. Also, like any good dogma, it reinforces a hierarchical idea of authority. The central dogma is all about keeping the DNA in charge. The fact that in reality information flows every which way shouldn't upset the idea of DNA as paterfamilias.

To be fair, when Hartl and Jones describe the central dogma, they don't mention the "and this is the only way information flows" part. They simply discuss the processes of replication, transcription and translation. The other genetic textbook I have in my office (Klug and Cummings 2003) doesn't use the term central dogma at all, it only talks about the processes of replciation, transcription and translation.


Citations:

Hartl, Daniel L., and Elizabeth W. Jones. 1998. Genetics: principles and analysis. 4th ed. Sudbury, Mass.: Jones and Bartlett Publishers. 076370489X. QH430.H3733 1998

Klug, William S., and Michael R. Cummings. 2003. Concepts of genetics. 7th ed. Upper Saddle River, N.J.: Prentice Hall. 0130929980. QH430.K574 2003