RT Journal Article
SR Electronic
T1 Phylogenetic incongruence and the origins of cardenolide-resistant forms of Na<sup>+</sup>, K<sup>+</sup>- ATPase in North American <em>Danaus</em> butterflies
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 048033
DO 10.1101/048033
A1 Matthew L. Aardema
A1 Peter Andolfatto
YR 2016
UL http://biorxiv.org/content/early/2016/04/10/048033.abstract
AB Rapid species radiations can obscure phylogenetic relationships between even distantly related species and lead to incorrect evolutionary inferences. For this reason, we examined evolutionary relationships among the three North American milkweed butterflies, Danaus plexippus, D. gilippus and D. eresimus using &gt;400 orthologous gene sequences assembled from transcriptome data. Contrary to previous phylogenetic assessments, our results indicate that D. plexippus and D. eresimus are the sister taxa among these species. This result explains many previously noted phylogenetic incongruences such as an amino acid substitution in the sodium-potassium pump (Na+,K+-ATPase) of D. eresimus and D. plexippus, which increases resistance to the toxins found in these butterflies’ host plants. In accordance with a rapid radiation of Danaus butterflies, we also find evidence that both incomplete lineage sorting and post-speciation genetic exchange have contributed significantly to the evolutionary histories of these species. Furthermore, our findings suggest that D. plexippus is highly derived both morphologically and behaviorally.