Genome-wide miRNA and protein coding expression of Danaus plexippus fed on three different hosts.

Second instar larvae of the monarch butterfly, Danaus plexippus, from a nonmigratory population in Irapuato, Mexico, were reared for twenty-four hours on three species of milkweed hosts: Asclepias curassavica, A. linaria, and Gomphocarpus physocarpus. The greatest differences in coding gene expression occurred in genes controlling growth and detoxification and were most extreme in comparisons between G. physocarpus and the two Asclepias. MicroRNAs are predicted to be involved as regulators of many of these processes, in particular miR-278 could be an important regulator of growth through Hippo signaling. 9 poly(A) and 9 sRNA libraries were prepared from Danaus pleixppus second instar larvae after feeding for 24 hours on three different hosts to identify genes potentially involved in host specificity.