Un-Junking Junk DNA is hot off the presses. “Islands” of protein coding DNA are separated by “oceans” (large swaths of “junk” DNA) that appear to be important in determining just how the mRNA in these islands is alternatively spliced together to make a variety of different proteins. Conventional definitions of DNA superstructure require these islands of DNA to be separated by vast stretches of junk DNA. If so, how do they physically interact? Could it be that DNA structure is being over simplified? Perhaps, the linear DNA model should be modified like the time-space model. It can curve onto itself and even make “worm holes” that allow interactions between the junk DNA and the protein-coding DNA that generate potential mRNA splicing pathways. In other words, the DNA is more circular than linear. Check out these two models in which circular DNA elements involving both protein-coding and “junk” DNA can be used to generate mRNAs using alternative splicing.
Intron lariat model
Linear intron model