The comparison of outputs from two types of photoreceptors, R7 and R8 Drosopholia color vision is formed.
Explanation:
The R7 photoreceptor cell is the last photoreceptor that is recruited into the ommatidal cluster and it is followed by four nonneuronal cone cells.
The differentiation of R7 photoreceptor cells requires signalling through two receptor tyrosine kinases, and the epidermal growth factor receptor.
The another factor for this differentiation into R7 cell are encoded by the seven in abstensia and phyllopod genes. In the absence of phyl, the R1, R6, and R7 cells are transformed into additional cone cells.
The activein receptor is required in R8 to receive non-redudant signalling from three Activin ligands that activates the transcription factor.
