Fig. 2: Vsx1–Hth neuronal cell bodies occupy distinct regions along the A–P axis of the adult medulla cortex, correlating to their sequential birth order in the larva.
From: Concurrent temporal patterning of neural stem cells in the fly visual system
a and b Schematics depicting cell body positions of Vsx1–Hth neurons in the medulla cortex as visualized in horizontal (a) and frontal (b) orientations of the optic lobe. c–e Early-born medulla neurons generated from 48 h ALH to the cessation of larval feeding (92 h ALH) are labeled by EdU (red, d). Late-born neurons generated after the feeding window (96 h ALH to 15 h APF) are labeled by memory trace experiments (βGal, green, e). Arrows indicate the extent of neurons labeled across the A–P axis by EdU feeding (d) and memory trace (e) experiments. f–i 48–92 h ALH EdU feeds (red) label Zfh1++ TmY17 neurons (cyan, f) and Br+ TmY15 neurons (blue, g), but not Mamo++ Tm23 neurons (white, h) or Zfh1+ Pm3 neurons (cyan, i). j and k 72–78 h ALH EdU feeds (red) label Zfh1++ TmY17 neurons (magenta, j), but not Zfh1- TmY15 neurons (k). l and m 84–90 h ALH EdU feeds (red) do not label Zfh1++ TmY17 neurons (magenta, l), but do label Zfh1- TmY15 neurons (m). n Quantification of (j–m). The percentage of Vsx1–Hth EdU+ cells in the adult identified as TmY17, TmY15, Tm23, and Pm3 was quantified for 6 h EdU feeds at four developmental stages (63–69 h ALH n = 8 neurons; 72–78 h ALH n = 37 neurons; 78–84 h ALH n = 23 neurons; 84–90 h ALH n = 35 neurons). Error bars denote SEP. Source data are provided as a Source Data file. o Quantification of Supplementary Fig. 4a–j. The percent of TmY17, TmY15, Tm23, and Pm3 neurons labeled by a pxb-Gal4 memory trace after heat shock induction at four different developmental stages (86 h ALH n = 439 Pm3s, 29 Tm23s and 653 TmY15s; 92 h ALH n = 664 Pm3s, 31 Tm23s and 578 TmY15s; 0 h APF n = 586 Pm3s and 46 Tm23s; 10 h APF n = 476 Pm3s). Error bars denote SEP. Source data are provided as a Source Data file. p Schematic displaying the birth windows of Vsx1–Hth neuron types over the course of neurogenesis based on EdU and genetic birthdating analysis. q Model illustrating the relationship between neuronal birth order and proneural wave propagation in the medial (anterior) to lateral (posterior) direction during medulla neurogenesis. In all images and schematics: Anterior/medial is left. Dorsal is up in (b). White arrowheads indicate neuronal cell bodies in (f–m). Scale bar: 15 µm.
