Meeting Abstract
Insects typically have three to five functional opsins responsible for detecting different wavelengths of light and these opsins are essential to see colour. Nocturnal and diurnal insects have vastly different conditions in which their visual system function, both in the amount of background illumination as well as spectral properties of the visual stimuli they need to detect. This results in different selective pressures on their visual genes and quantification of the purifying or diversifying selection acting on different opsins can be used to infer their relative importance for day and night vision. There has been an increase in the number of insect genomes and transcriptomes publicly available and we use these data to examine the evolution of opsins across insect lineages. We use a phylogenetically informed annotation approach to identify opsins and model rates of evolution of opsins and duplication and deletion events. We detect multiple opsin duplications and deletions as well as different rates of sequence evolution between opsins; we also test if this linked to their diel activity period. We find that UV opsins in particular have significantly different rates of selection between some nocturnal and diurnal insects and discuss the possible biological reasons behind the differential rates of selection. We explore some of these ideas such as the effect of light level on colour perception in the UV and the role of UV reflectance in plant-pollinator interactions.
