Figure 1. Lamina Wide-Field Neurons Express Specific Transcription Factors.

(A) Lamina wide-field neurons have cell bodies in the medulla cortex and arborizations in both the lamina and medulla neuropils. Lawf1 cells (blue) project to layers M1 and M3 of the medulla, whereas Lawf2 cells (magenta) project to M1 and M9. The locations of adult epithelial glia (eg) and marginal glia (mg) are also shown. Adapted from Tuthill et al. (2013) and Edwards et al. (2012).

(B and C) 1118-Gal4 drives expression in Lawf1 neurons in adults. Lawf1s express Eya (blue in B) and Hth (red in C) but not Lim1 (red in B).

(D–E) 11D03-Gal4 drives expression in Lawf2s in adults (green). Lawf2 neurons express Lim1 (red in D) and Hth (red in E). While most Lawf2 neurons express Eya (arrows, magenta cells in D), some do not (arrowheads in D and D′).

(F) Schematic drawing of larval optic lobe and Lawf positions (sagittal cross section).

(G) In larval brains, Lawf1 neurons express Hth (green) and Eya (blue); Lawf2 neurons express Lim1, Hth, and Eya.

(H–K′) 17C11-Gal4 drives expression in both Lawf1s and Lawf2s. (H) In a later larval brain, all Lawf neurons are Eya⁺. (I) At the prepupal stage, the two Lawf populations move toward each other (curved arrows). (J) One day into pupation, Lim1⁺ Lawf2 and Lim1⁻ Lawf1 populations migrate to populate the entire medulla cortex and intermingle with each other. Eya is lost in some Lawf2 neurons (arrows). (K) Two days into pupation, Lawf1 and Lawf2 populations form their arborization patterns in the lamina and medulla neuropils. 17C11-Gal4 expression is reduced in Lawf2s. Blue arrow points to a Lawf1 cell body. Blue arrowhead points to Lawf1 projections in the M3 layer. Magenta arrow points to a Lawf2 cell body. Magenta arrowhead points to Lawf2 projections in the M3 layer.

(L) In the adult, 17C11-Gal4 labels Lawf1 strongly and Lawf2 weakly.

See also Figure S1.