A Genetic Oddity May Give Octopuses and Squids Their Smarts

According to a study from NY times, Coleoid cephalopods are the most intelligent invertebrates for their behavioral complexity through RNA editing. Coleoid cephalopods is a group compassing octopus, squids, and cuttlefish. Research has revealed that natural selection favored the RNA editing of the coleoids and slowed the DNA-based evolution that helped the organisms to have beneficial adaptations over time. The enzymes of these cephalopods swap out some of the letters (ACGU) of RNA encoding and produced modified RNA which creates proteins that weren't originally encoded in the DNA sequences. The coleoid genes share tens of thousands of these RNA editing sites which markably contained DNA mutations that leads to the source of new traits for adaptation of the organisms. Additionally, the RNA editing allows the invertebrates to swiftly manipulate their nervous system and to have dynamic control over proteins based on different environmental conditions or tasks. In octopus, RNA editing aids to quickly adapt to the changes in temperature.

I find it very interesting how the swapping of the RNA encoding letters in the coleoid genes creates DNA mutations which leads to advantageous traits for the organisms for adaptation. It is amazing how mutations in these invertebrates can be beneficial while in humans it can cause major defects.

Calling all the Crown-of-Thorns

The Crown-of-Thorns Starfish is known as the "Demon Starfish"in Japan and with good reason these predators swarm coral reefs with their spawning events creating colonies with up to several million individuals which in turn devour the reef. This has become a huge environmental concern so efforts are being made to understand how it is that they communicate so efficiently to bring so many individuals together from Australia to Okinawa, and possibly control this invasive species. For this study researchers at University of the Sunshine Coast in Australia and the Okinawa Institute of Science and Technology teamed up and originally found that the starfish looked at in these two regions shared identical genetic material, meaning that the same species could be found 5000kms on the other side of the equator. The researchers then continued by identifying the water borne molecules the starfish used to communicate, then looking at genetic material that was decoded from two separate individuals from each region. In order to identify the genes collected they preformed an experiment where two Crown-of-Thorns were put in a Y-shaped aquatic maze at separate ends and fed the one at the shorter branch of the Y with water collected form an aggregation of the starfish, as the other one moved towards this branch they suspected that they could find the molecules in the water that induced the starfish to gather. The water was then analyzed and mapped to the starfishes genomic data, and they were able to confirm that the molecules originated from the Crown-of-Thorns because the scientists now had the full genome. Ultimately they exposed 26 specific genes that could take part of production of the 107 water borne communicating signals. The researchers also found that the genome included 750 genes that code for proteins connected to their version of a sense of smell. All of this information could help scientist potentially disrupt communication on a large scale to protect reefs and enforce biological control. I think this is important because it is an environmental issue considering how quickly coral reefs are diminishing and it gives more insight on evolutionary developmental biology.

For more information on biological control: https://biocontrol.entomology.cornell.edu/what.php
Article : https://www.sciencedaily.com/releases/2017/04/170405131003.htm

A Genetic Oddity May Give Octopuses and Squids Their Smarts

 

It has long been known that Coleoid cephalopods are the most intelligent invertebrates. They are able to do things that most invertebrates were never thought to be able to do, such as solving puzzles and having complex forms of communicating. A recent study conducted on two octopuses, one squid, and one cuttlefish by scholars at Tel Aviv University show that their sophistication could be due to a quirk in how their genes work. Since they make extensive use of RNA editing, they have a significant diversity in their nervous system proteins compared to most animals.  As described in a separate article about types of RNA editing, RNA editing is an alteration of RNA sequences and structures by modification, deletion or by the insertion of nucleotides. Since this was occurring more so in colloids than other animals three separate doctors set out to quantify the disagreements of DNA and RNA sequences only to find that they have tens of thousands of recoding sites. When they looked at less sophisticated mollusks they found that the editing was occuring at a much smaller magnitude and could not be compared to the octopus, squid, or cuttlefish. They also compared the recoding sites between the three species and compared them, showing that they share tens of thousands of these sites compared to humans and mice who only share about 40 recoding sites even though we are hundreds of millions of years closer in evolution than octopuses and squids. This is important research because there is still so much unknown about the cuttlefish and some species of octopuses who are extremely complex compared to other invertebrates. This research provides more insight to the ongoing question of how they are so capable of the expressing the behaviors that they do. 

https://www.nytimes.com/2017/04/06/science/octopus-squid-intelligence-rna-editing.html?rref=collection%2Fcolumn%2Ftrilobites&_r=0

http://www.news-medical.net/life-sciences/Types-of-RNA-Editing.aspx