phyl cDNA is expressed under the transcriptional control of an Hsp70 promoter and two copies of the sev enhancer.
cone cell | precursor
eye
photoreceptor cell R7
Eyes are roughened. Ectopic R7 cells develop. Additional R7 cells is independent of sev activity but depends on sina function. Additional R7 cells are derived from cone cell precursors. Eyes are roughened. Ectopic R7 cells develop.