Is there an authority on definitions for molecular microbiology concepts, like an IUPAC book for chemical definitions?

The particular definition I am debating is chromatin. Some say it encompasses DNA, RNA and protein, whilst others say that it contains DNA and only during the mitotic interphase can it transcribe to produce RNA and protein.

  • $\begingroup$ What you are asking about is molecular biology, not microbiology. $\endgroup$
    – Chris
    Feb 19 '15 at 6:33

So in a very broad definition, yes, chromatin encompasses DNA, RNA and protein. The primary function of chromatin is to provide a method to effectively package all the DNA in a cell. This packaging is dynamic, and it's constantly regulated in a cell type-specific manner. We can see the broad interactions of protein and DNA in this cartoon representation from wikipedia:

enter image description here

Combined with histone-modifying complexes, and chromatin remodeling complexes, we obtain the aforementioned mode of regulation. Histone protein can be modified (acetylation, methylation, glycosylation, phosphorylation, etc.), they can also be moved, substituted in their subunits for specific pruposes (think H3.3 or H2A.X). We can also end up with varying regions of dsDNA, 10nm or 30nm fiber.

The RNA comes in as a structural and functional components of the chromatin, participating in many controls as noncoding RNAs.

I believe most of the method in defining chromatin comes in very much as the amassed literature on the subject to-date. You'd even consider it "common knowledge" entering the field (i.e. a quick google search can return you the right definition).

"only during the mitotic interphase can it transcribe to produce RNA and protein."

Transcription halts entering M phase or mitosis, transcription may occur during G1, S, G2, or "interphase."


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