2017/04/07

World's fastest mutations or a clever mechanism?

Octopuses Frequently Edit Their Own Genes

https://www.labroots.com/trending/plants-and-animals/5723/octopuses-frequently-edit-own-genes

Excerpt: "Cephalopods, the branch of animals dealing primarily with octopuses and squids, are much more unique than previously thought.

While they’ve long been understood to have a far-reaching sense of intelligence, no one would have guessed that they had the ability to influence their own genes. On the other hand, that’s exactly what researchers found out before publishing a study in the journal Cell.

Apparently, cephalopods are capable of interfering with the process where DNA gets transcribed into RNA. This little act of interference and re-coding causes ribosomes to interpret the modified RNA the way they would normally interpret non-modified RNA, and hence, the creature manages to influence its own protein production.

Interestingly, this gene-editing ability leads to quite a few genetic variations in the cephalopod community, as even the slightest change in the creature’s genetics can set off a domino effect that triggers major changes.
 

For example, it gives the creature the ability to be as versatile as it needs to be for the world’s ever-changing environment; this might include adjusting its color to better avoid predators or hide from prey, changing behavioral tactics to improve intelligence and fit in with other creatures, increasing their tolerances for different temperatures, and other changes.

The process is not yet fully understood, but because there is so much interest in how cephalopods are able to go about this feat, the research continues…

“When do they turn it on, and under what environmental influences? It could be something as simple as temperature changes or as complicated as experience, a form of memory,” study lead author Joshua Rosenthal said.

Cephalopods certainly aren’t the only creatures capable of carrying out this activity, but they do it in exponentially higher frequencies than other known animals that undertake this behavior. Even humans have this ability, but it’s extremely rare that we manage to go about it.

For what it’s worth however, this gene re-coding superpower comes at a cost. Cephalopods don’t exhibit that much natural evolution as a result of their transcriptome plasticity. Instead, the latter takes the higher priority.

It should be interesting to see what we can learn about cephalopods, which appear to be far more misunderstood than originally thought. Perhaps the research will help us further our own genetic research."

My comment: What science can learn about cephalopods, is an understanding that changes in nature don't occur by chance. Cephalopods are capable of rapid RNA editing, which means they are able to modify the RNA transcripts on the fly. I
n practise, every case of organisms variation and adaptation in nature is based on this same epigenetic mechanism. It's just that there are a lot of variation in response times between organisms. A few examples:

1. Guinea pigs tweak their own DNA for preparing the next generation for changing climate:
https://www.newscientist.com/article/dn28733-guinea-pigs-beat-climate-change-by-tweaking-their-own-dna/

2. Lizards can modify their RNA transcripts for being able to digest plant based food:
http://www.sciencemag.org/news/2016/06/how-does-lizard-go-vegetarian-growing-its-gut

3. Corals modify their genetic make-up when adapting into changing environment:
https://www.sciencedaily.com/releases/2016/01/160107095039.htm

Changes in organisms are based on mechanisms, not random mutations or natural selection. Don't get lost.