Extended Data Fig. 4: Differences in G2 duration do not compensate for the long G1.
From: Stem cell regulators drive a G1 duration gradient during plant root development
a, G2 progression by measuring the appearance of mitotic cells labeled after an EdU pulse (15 min). Unlabeled (blue dots) and labeled (red dots) mitosis were scored at various chase times after the EdU pulse, according to their position along the RAM (0.0 = QC, 1.0 = RAM boundary, as described in Fig. 1c). Quantifications were carried out separately for various cell types, as indicated. b, Quantification of EdU-labeled mitosis at various chase times in two regions of the RAM: distal (empty squares) corresponds to the region located between the position 0.0 (QC) up to 0.4 of the RAM; proximal (filled circles) includes the rest of the RAM (from 0.4 to its boundary at 1.0). Data are mean values ± s.d. The experiment was carried out in duplicate, processing 5 roots per biological replicate for each chase time. Total number of cells analyzed for each cell type was: atrichoblasts (n = 312 EdU–, n = 75 EdU + ), trichoblasts (n = 237 EdU–, n = 42 EdU + ), cortex (n = 401 EdU–, n = 139 EdU + ), endodermis (n = 495 EdU–, n = 237 EdU + ). c, Live-imaging of cells showing the dynamics of CYCB1;1 loading in late G2 and its degradation at the metaphase/anaphase transition. Two examples of cells with a relatively short (upper panel; atrichoblast located at relative position 0.41 of the RAM) and long (lower panel; trichoblast at position 0.37) G2+prophase+metaphase period (black bars under each panel) are shown. Scale bar = 10 µm. d, Duration of the CYCB1;1 wave (time between first detectable signal and complete degradation of CYCB1;1 at the metaphase/anaphase transition) along the root meristem in four root cell types, as indicated. Total n = 75 cells, 4 roots.
