Editing Convergent evolution (section)

====Na<sup>+</sup>,K<sup>+</sup>-ATPase and Insect resistance to cardiotonic steroids ====

Many examples of convergent evolution exist in insects in terms of developing resistance at a molecular level to toxins. One well-characterized example is the evolution of resistance to cardiotonic steroids (CTSs) via amino acid substitutions at well-defined positions of the α-subunit of [[Na+/K+-ATPase|Na<sup>+</sup>,K<sup>+</sup>-ATPase]] (ATPalpha). Variation in ATPalpha has been surveyed in various CTS-adapted species spanning six insect orders.<ref name="Zhen_et_al_2012">{{cite journal |last1=Zhen |first1=Ying |last2=Aardema |first2=Matthew L. |last3=Medina |first3=Edgar M.|last4=Schumer|first4=Molly|last5=Andolfatto |first5=Peter|date=2012-09-28|title=Parallel Molecular Evolution in an Herbivore Community |journal=Science |volume=337 |issue=6102 |pages=1634–1637 |doi=10.1126/science.1226630 |pmid=23019645 |pmc=3770729 |bibcode=2012Sci...337.1634Z}}</ref><ref>Dobler, S., Dalla, S., Wagschal, V., & Agrawal, A. A. (2012). Community-wide convergent evolution in insect adaptation to toxic cardenolides by substitutions in the Na,K-ATPase. Proceedings of the National Academy of Sciences, 109(32), 13040–13045. https://doi.org/10.1073/pnas.1202111109</ref><ref name="Yang_et_al_2019">{{cite journal |last1=Yang |first1=L. |last2=Ravikanthachari|first2=N|last3=Mariño-Pérez|first3=R|last4=Deshmukh|first4=R|last5=Wu |first5=M. |last6=Rosenstein |first6=A. |last7=Kunte|first7=K. |last8=Song |first8=H. |last9=Andolfatto |first9=P. |display-authors=3 |title=Predictability in the evolution of Orthopteran cardenolide insensitivity |journal=Philosophical Transactions of the Royal Society of London, Series B |date=2019 |volume=374 |issue=1777 |pages=20180246 |doi=10.1098/rstb.2018.0246 |pmid=31154978 |pmc=6560278}}</ref> Among 21 CTS-adapted species, 58 (76%) of 76 amino acid substitutions at sites implicated in CTS resistance occur in parallel in at least two lineages.<ref name="Yang_et_al_2019"/> 30 of these substitutions (40%) occur at just two sites in the protein (positions 111 and 122). CTS-adapted species have also recurrently evolved [[Neofunctionalization|neo-functionalized]] duplications of ATPalpha, with convergent tissue-specific expression patterns.<ref name="Zhen_et_al_2012"/><ref name="Yang_et_al_2019"/>