Ability To Edit RNA Makes Octopus & Squid Smarter Cephalopod Species

In the world of the living organisms humans are always considered as the intelligent creature, but there are some other species in water world that fascinate humans for their intense smartness. In the prior experiments, scientists noticed that Coleoid cephalopods such as octopus, squid, and cuttlefish have special ability to unlock jars, escape tanks, and communicate with their own codes.

A joint research team from Marine Biological Laboratory (MBL), Woods Hole and Tel Aviv University found in the latest study that cephalopods have a complex mechanism in their evolutionary path of neural sophistication. In the Cell journal, researchers described that octopus and squids can rewrite their RNA codes in their nervous system cells which allow them to diversify the proteins that the cells can produce.

Generally, humans or fruit flies can only transcript fraction of one percent RNA during the rewriting event in the brain, but a cephalopod brain can transcript up to 60 percent of RNA. Researchers noticed a high level of RNA editing in three cephalopods which include two octopi and one cuttlefish. According to ScienceDaily, these cephalopods are named as “Coleoid” and they have tens of thousands of evolutionarily conserved RNA recoding sites.

Proteins were affected during the editing process in the Coleoid nervous system that plays a lead role in neural excitability and neuronal morphology. Compared to Coleoids, RNA editing is more primitive in cephalopod Nautilus and mollusk Aplysia as it occurs in lower magnitude.

Lead researcher Joshua J.C. Rosenthal from MBL said in the report,“This shows that high levels of RNA editing is not generally a molluscan thing, it's an invention of the Coleoid cephalopods”. he also explained that the editing process is driven by ADAR enzymes.

ADAR requires large flanking structures named dsRNA in editing sites which help to span hundreds of nucleotides in the Coleoid genome. The flanking regions depress the genetic mutation rates. Now, scientists are planning to develop genetically tractable cephalopod model to deeply understand the mechanism and functional consequences of their RNA editing.