Expression of PoPer mRNA in spring foragers (DD conditions). Relative expression of period mRNA in individual forager brains from three experimental colonies of P. occidentalis collected in the spring and entrained in a 24 hr DD regime (w/SE). Bars represent the averages of colony means with three foragers sampled per colony (SE calculated from colonies). The gray stripe in the horizontal bar at base of the plot represents the subjective light phase and the solid stripe represents the dark phase in DD conditions.
Ingram et al. BMC Ecology 2009 9:7 doi:10.1186/1472-6785-9-7