Do I understand correctly that these new functions come into play upstream of messenger RNA? So the new chain would be DNA+Introns => lots of control functions => much tailored mRNA => any of a number of different proteins from the same DNA?
It is not exactly like you described. Its splicing site which are specific sequence can be target by the splicesome in a given cellular state. The mRNA is intron and exon. The splicing removes the introns and keeps the exons. The difference is that some exons migth be reject for a certain function but kept for another function. As you said you get many tailored made processed mRNA which in term increase the potential number of protein.
Upstream of mRNA is a region called the 3'UTR (untranslated region) which plays a role in regulating the translation of the sequence.
Is there any account of this that gives some detail but is accessible to a general reader?
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