Elixir
Made in America
Some interesting stuff...
I have seen some commentary to the effect that RNA editing could provide a loophole in the existing ethical restrictions to DNA editing, though I can't really see the difference since the outcomes are in the same realm. What really interests me is the evolutionary tradeoff - these organisms have greatly reduced response times to some environmental changes, but retention of that capability puts them in a genomic rut, which could be their undoing under some conditions.
PLOS Blog
Octopuses, Squid, and Cuttlefish: RNA Editing Instead of Genome Evolution?
"A paper just published in Cell highlights another intriguing characteristic of the coleoids: their ability to “edit” some of their RNA, which changes the encoded proteins faster than can DNA mutation. In contrast RNA editing in mammals is not only unusual, but confined mostly to non-protein-encoding RNAs. In the coleoids, an enzyme changes “A” (adenine) RNA bases into “I” (inosine) bases, which results in a G (guanine) replacing an A."
http://www.cell.com/cell/fulltext/S0092-8674(17)30344-6
"RNA editing, a post-transcriptional process, allows the diversification of proteomes beyond the genomic blueprint; however it is infrequently used among animals for this purpose. Recent reports suggesting increased levels of RNA editing in squids thus raise the question of the nature and effects of these events. We here show that RNA editing is particularly common in behaviorally sophisticated coleoid cephalopods, with tens of thousands of evolutionarily conserved sites. Editing is enriched in the nervous system, affecting molecules pertinent for excitability and neuronal morphology. The genomic sequence flanking editing sites is highly conserved, suggesting that the process confers a selective advantage. Due to the large number of sites, the surrounding conservation greatly reduces the number of mutations and genomic polymorphisms in protein-coding regions. This trade-off between genome evolution and transcriptome plasticity highlights the importance of RNA recoding as a strategy for diversifying proteins, particularly those associated with neural function."
I have seen some commentary to the effect that RNA editing could provide a loophole in the existing ethical restrictions to DNA editing, though I can't really see the difference since the outcomes are in the same realm. What really interests me is the evolutionary tradeoff - these organisms have greatly reduced response times to some environmental changes, but retention of that capability puts them in a genomic rut, which could be their undoing under some conditions.
PLOS Blog
Octopuses, Squid, and Cuttlefish: RNA Editing Instead of Genome Evolution?
"A paper just published in Cell highlights another intriguing characteristic of the coleoids: their ability to “edit” some of their RNA, which changes the encoded proteins faster than can DNA mutation. In contrast RNA editing in mammals is not only unusual, but confined mostly to non-protein-encoding RNAs. In the coleoids, an enzyme changes “A” (adenine) RNA bases into “I” (inosine) bases, which results in a G (guanine) replacing an A."
http://www.cell.com/cell/fulltext/S0092-8674(17)30344-6
"RNA editing, a post-transcriptional process, allows the diversification of proteomes beyond the genomic blueprint; however it is infrequently used among animals for this purpose. Recent reports suggesting increased levels of RNA editing in squids thus raise the question of the nature and effects of these events. We here show that RNA editing is particularly common in behaviorally sophisticated coleoid cephalopods, with tens of thousands of evolutionarily conserved sites. Editing is enriched in the nervous system, affecting molecules pertinent for excitability and neuronal morphology. The genomic sequence flanking editing sites is highly conserved, suggesting that the process confers a selective advantage. Due to the large number of sites, the surrounding conservation greatly reduces the number of mutations and genomic polymorphisms in protein-coding regions. This trade-off between genome evolution and transcriptome plasticity highlights the importance of RNA recoding as a strategy for diversifying proteins, particularly those associated with neural function."
