Junk DNA, High R, Pinnipeds, and the Multiverse

[Rumraket (Mikkel R.)]

@Nesslig20

To me, this suggests that the formation of spurious high-active promoters is far less likely to occur in eukaryotes, resulting in a lower genetic load per base pair.

That does appear to be the case, at least with respect to high expression levels. However, there is counterintuitively an even higher fraction of DNA that elicits transcriptional activity by eukaryotic initiators, than in prokaryotes. Though the expression levels are lower on average.

Someone did the Yona et al 2018 experiment, but with a eukaryote!

The article Yona et al. 2018 (Random sequences rapidly evolve into de novo promoters) has come up here before, because it shows that random DNA sequences easily and quickly can evolve into functional promoters in bacteria. It has been an open question how prevalent expression from random DNA sequences would be when integrated in eukaryotic chromosomes, that typically are wrapped up tightly into chromatin complexes. A similar experiment has now been done on yeast, a eukaryotic organism, and remarkably the numbers that a random sequences can function as a promoter are surprisingly close to those in prokaryotes: Xu, H., Li, C., Xu, C. et al. Chance promoter activities illuminate the origins of eukaryotic intergenic transcriptions. Nat Commun 14 , 1826 (2023). Chance promoter activities illuminate the origins of eukaryotic intergenic transcriptions | Nature Communications Abstract It is debated whether the pervasive intergenic transcription from eukaryotic genomes has functional signi…