Gene expression
Eastern and western monarchs were randomly selected, flown on the flight
mill for two minutes, and immediately frozen in liquid nitrogen prior to
RNA extraction. Overall, the expression of the six candidate genes
varied widely between individual butterflies, and expression of several
genes tended to be higher in western monarchs (Fig. 8). Mann-Whitney U
tests showed that western monarchs had significantly higher expression
of the myosin heavy chain gene associated with non-muscular motor
activity (Fig. 8; DPOGS215054; P=0.039).