Last year we got funding for a very exciting project: we will try to create genetically modified bumblebees with four photoreceptor types, with peak sensitivities in the UV, blue, green and red regions of the spectrum. The question underlying this project is whether the “mere” acquisition of a new photoreceptor type immediately leads to an increase in the dimensionality of colour perception. Does the brain have enough plasticity to extract the additional information that it is receiving, or is the connectivity so rigid that it treats information arriving from “red” receptors as if they were (say) “green” receptors?
To answer this question we will try to insert into the bumblebee genome a gene, coding for a red-sensitive opsin, from the Asian swallowtail butterfly Papilio xuthus. But to maximise the chances that the gen is expressed in some photoreceptors instead of the gene coding for a different opsin, we first have to figure out how retina formation is regulated in developing bumblebees.