Imagine my surprise when I saw that he has a link to the Wikipedia article on the Central Dogma. I said to myself, "This will set him straight because I wrote some of that article."
Oops! The Wikipedia article on the Central Dogma of Molecular Biology has been changed. Apparently I haven't looked at it for nine years since the important change was made by someone named Kierano back on September 15, 2006. Kierano describes himself (in 2011) as a Ph.D. student in bioinformatics.
Here's the opening paragraphs from before Sept. 15, 2006.
The central dogma of molecular biology was first enunciated by Francis Crick in 1958 and re-stated in a Nature paper published in 1970:This has undergone some edits from what I originally wrote but the main idea is there. Strictly speaking, the Central Dogma of Molecular Biology (Crick version) says only that once information gets into protein it can't flow back to nucleic acid. I thought it was important to explain the main misconception; namely, that the Central Dogma means DNA to RNA to protein. This should be referred to as "the standard information flow pathway" or something similar.The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred from protein to either protein or nucleic acid.In other words, 'once information gets into protein, it can't flow back to nucleic acid.'
The central dogma is often misunderstood. It is frequently confused with the standard pathway of information flow from "DNA to RNA to protein". There are notable exceptions to the normal pathway of information flow and these are often mistakenly referred to as exceptions to the central dogma.
The standard information flow pathway can be summarized in a very short and oversimplified manner as "DNA makes RNA makes proteins, which in turn facilitate the previous two steps as well as the replication of DNA", or simply "DNA → RNA → protein". This process is therefore broken down into three steps: transcription, translation, and replication. By new knowledge of the RNA processing, a fourth step must be included: splicing.
The rest of the Wikipedia article talks about transcription and translation which, strictly speaking, are not part of the Central Dogma. However, the misconception is so widespread that many people expect these to be described under "Central Dogma."
The new version posted on Sept. 15, 2006 says ...
The central dogma of molecular biology was first enunciated by Francis Crick in 1958 and re-stated in a Nature paper published in 1970:This is the beginning of a change in emphasis. Kierano removed my statement that the basic meaning of the Central Dogma is often misunderstood. It's clear that he misunderstands it.The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred from protein to either protein or nucleic acid.In other words, 'once information gets into protein, it can't flow back to nucleic acid.'
The dogma is a framework for understanding the transfer of information between information-carrying biopolymers, in the most common or general case, in living organisms. There are 3 major classes of information-carrying biopolymers: DNA and RNA (both nucleic acids), and protein. There are 9 possible direct transfers of information that can occur between these. The dogma classes these into 3 general transfers (believed to occur normally in most cells), 3 special transfers (known to occur, but only under abnormal conditions), and 3 unkown transfers (believed to never occur). The general transfers describe the normal flow of biological information: DNA can be copied to DNA (DNA replication), DNA information can be copied into mRNA, (transcription), and proteins can be synthesized using the information in mRNA as a template (translation).
The central dogma is occasionally misunderstood as being a statement of absolute fact. If taken as such, it can be criticised, as there are well-described exceptions. It is also criticised by some systems biologists as being too reductionist.
On March 10, 2012 someone named Nbauman addd the following statement; "Or, as Marshall Nirenberg said, 'DNA makes RNA makes protein.'" Nbauman cautioned that this was a reliable published source and should not be removed from the Wikipedia article. As far as I can tell Nbauman is not a scientist and has no training in science. In fact, she seems proud of the fact that she is ignorant of the subjects she edits. She does not seem to have noticed that her "authority" (Nirenberg) conflicts with another authority (Francis Crick).
Here's the complete version as of this morning. It's going to change as soon as I get around to it.
The central dogma of molecular biology is an explanation of the flow of genetic information within a biological system. It was first stated by Francis Crick in 1958[1] and re-stated in a Nature paper published in 1970:The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred back from protein to either protein or nucleic acid.Or, as Marshall Nirenberg said, "DNA makes RNA makes protein."[3]
To appreciate the significance of the concept, note that Crick had misapplied the term "dogma" in ignorance. In evolutionary or molecular biological theory, either then or subsequently, Crick's proposal had nothing to do with the correct meaning of "dogma". He subsequently documented this error in his autobiography.
The dogma is a framework for understanding the transfer of sequence information between sequential information-carrying biopolymers, in the most common or general case, in living organisms. There are 3 major classes of such biopolymers: DNA and RNA (both nucleic acids), and protein. There are 3×3 = 9 conceivable direct transfers of information that can occur between these. The dogma classes these into 3 groups of 3: 3 general transfers (believed to occur normally in most cells), 3 special transfers (known to occur, but only under specific conditions in case of some viruses or in a laboratory), and 3 unknown transfers (believed never to occur). The general transfers describe the normal flow of biological information: DNA can be copied to DNA (DNA replication), DNA information can be copied into mRNA (transcription), and proteins can be synthesized using the information in mRNA as a template (translation).
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