Science. 1986 Jan 24;231(4736):400-2. doi: 10.1126/science.231.4736.400.
Each ommatidium in the compound eye of the Drosophila mutant sevenless lacks photoreceptor number seven (R7) from the normal ommatidial complement of eight photoreceptors. A comparison of mutant and normal development reveals that this deficit is caused by the cell-specific transformation of the cell normally fated to produce R7 into a lens-secreting accessory cell, a cone cell.
果蝇突变体 sevenless 的复眼的每个小眼都缺少正常小眼 8 个光感受器中数目的第七个光感受器（R7）。突变体和正常发育的比较揭示了这种缺陷是由于正常产生 R7 的细胞特异性转化为分泌晶状体的附属细胞，即视锥细胞而引起的。
