Editing Octopus (section)

===RNA editing and the genome===

Octopuses, like other coleoid cephalopods but unlike more [[Basal (phylogenetics)|basal]] cephalopods or other molluscs, are capable of greater [[RNA editing]], changing the [[nucleic acid sequence]] of the [[primary transcript]] of RNA molecules, than any other organisms. Much editing is done in the nervous system, particularly for [[Membrane potential#Cell excitability|excitability]] and neuronal morphology. Coleoids rely mostly on [[ADAR]] enzymes for RNA editing, which requires large, [[double-stranded RNA]] structures. The many editing sites are [[Conserved sequence|conserved]] in the coleoid genome and the mutation rates for the sites are hampered. Hence, greater transcriptome plasticity has come at the cost of slower genome evolution.<ref>{{cite journal |last1=Liscovitch-Brauer |first1=N. |last2=Alon |first2=S. |last3=Porath |first3=H. T. |last4=Elstein |first4=B. |last5=Unger |first5=R. |last6=Ziv |first6=T. |last7=Admon |first7=A. |last8=Levanon |first8=E. Y. |last9=Rosenthal |first9=J. J. C. |last10=Eisenberg |first10=E. |year=2017 |title=Trade-off between transcriptome plasticity and genome evolution in cephalopods |journal=Cell |volume=169 |issue=2 |pages=191–202 |doi=10.1016/j.cell.2017.03.025 |pmid=28388405 |pmc=5499236}}</ref>

The octopus genome is unremarkably [[bilaterian]] except for large developments of two gene families: [[protocadherin]]s, which regulate the development of neurons; and the [[C2H2 zinc-finger]] transcription factors. Many novel genes in both cephalopods generally and octopus specifically manifest in the animals' skin, suckers, and nervous system.<ref name="Albertin Simakov 2015"/>