Our experimental system is the Drosophila compound eye.
Tools used in our research include genetics, molecular and cell biology.
However, inhibitory regulation that is required to control cellular competence to respond to inductive signals is less understood. Loss of the yan or ttk function results in the differentiation of ectopic photoreceptors. In the presumptive R7 photoreceptor cells, both yan and ttk appear to act antagonistically to the proneural signal mediated by sevenless and Ras1. Moreover, yan and ttk synergistically interact to inhibit the formation of R7 cells. Thus, yan and ttk constitute of a negative nuclear regulatory system that maintains precursor cells in an undifferentiated state until they receive positive signaling, for example, the sevenless-mediated signaling for the development of R7 neuron.