You may have heard the catch phrase “follow the money” in the film, All the President’s Men. Following the money led to an understanding of just how everything works in a money-driven social environment.
The same thing may be said about palindromes in terms of biological evolution. A palindrome occurs in DNA or RNA and results in a form of molecular mirror image symmetry. When such DNA is melted and allowed to cool quickly, it snaps back on itself, forming characteristic hairpins of DNA or RNA.
Palindromes in DNA are generally associated with regions that are involved with DNA replication, gene expression, and cellular differentiation. In other words, they seem to be involved in starting points that make DNA “tick”.
In my last post, I discussed origins of replication as not only agents of replication and localized gene amplification, but also precursors to other elements such as promoters of transcription, enhancers of transcription, and splice sites for changing the very coding of the DNA itself. In all of these structures, palindromes seem to be lurking nearby in some form or another. I have designed some models to explain how origins of replication are formed, amplified, and converted into other structures like promoters, enhancers, and splice sites. However, be warned: This is not your typical linear DNA strand model so prevalent in textbooks and scientific literature. This model is based upon hierarchical DNA circular structures which are, themselves, composed of even smaller circles that may themselves be composed of still smaller circles and so on. You will need to dive into the blog further to get a better grasp of what this all means. However, I will place one set of models here again to get you on your way.
Fig. 1 (top left) undifferentiated DNA replicon cluster
Fig. 2 (top right) differentiated DNA replicon cluster
Fig. 3 (bottom left) RNA transcriptional pathway along the DNA
Fig. 4 (bottom right) splicing out of introns from pre-messenger RNA to generate messenger RNA