Fig. 1: Position of NER scales with cell size through scaling of anaphase chromosome velocity.
From: Cytoplasmic flow is a cell size sensor that scales anaphase
a, Time lapse of a cell in anaphase (8-cell stage). H2B–mCherry, chromosomes; NLS-GFP and WGA-640, nucleus. Only one set of chromosomes is shown. t = 0 s, anaphase onset. WGA and NER are indicated. Scale bar, 20 µm. b, Kymograph of the cell in a. c, Time of WGA and NER (by NLS-GFP) as a function of cell length. t = 0 s, anaphase onset. n = 17, 14, 4, 7, 12, 16, 16 and 14 cells from 17, 12, 4, 5, 5, 5, 5 and 5 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively. d, Position of WGA (n = 17, 14, 4, 7, 12, 16, 16 and 12 cells from 17, 9, 3, 5, 5, 5, 5 and 5 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively) and NER (n = 17, 14, 3, 7, 12, 16, 15 and 13 cells from 17, 9, 3, 5, 5, 5, 5 and 5 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively) as a function of cell length. e, Overlay of two timepoints for three developmental stages (4-, 32- and 128-cell stage), to visualize the scaling of NER. White, metaphase chromosomes; blue, chromosomes at NER. f, Cell size and position of NER in a 4-cell stage (yellow box; dashed line, cell boundary based on cytoplasmic NLS-GFP signal) and a 512-cell stage cell (white box). The NER distance in the large cell is longer than the cell size in the smaller cell. Scale bars, 10 µm. g, Semi-log plot of normalized pH3-s10 fluorescence levels for cells from 4- to 512-cell stages. The data are collapsed into a single exponential profile. n = 130 cells from 12 embryos, all developmental stages combined. h, Dephosphorylation rate of pH3-s10 (1/decay time) as a function of cell length. n = 9, 12, 11, 8, 14, 15, 15 and 14 cells from 9, 10, 10, 6, 9, 10, 9 and 7 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively. i, The normalized pH3-s10 fluorescence intensity at WGA (n = 2, 3, 2, 3, 5, 7, 10 and 12 cells from 2, 3, 2, 3, 2, 3, 4 and 4 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively) and NER (n = 2, 3, 2, 3, 5, 7, 10 and 10 cells from 2, 3, 2, 3, 2, 3, 4 and 4 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively) as a function of cell length. j, Distance between the two sets of chromosomes as a function of time. Colours, developmental stages (4- to 512-stage). t = 0 s, anaphase onset. n = 35, 42, 23, 28, 39, 58, 45 and 40 cells from 35, 34, 22, 22, 21, 23, 17 and 13 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively. k, Chromosome separation velocity as a function of cell length. vA (0–100 s) and \({v}_{{\mathrm{B}}}\) (100–200 s after anaphase onset). For \({v}_{{\mathrm{A}}}\), n = 26, 30, 17, 23, 35, 50, 43 and 40 cells from 26, 24, 16, 16, 17, 18, 17 and 13 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively. For \({v}_{{\mathrm{B}}}\), n = 34, 41, 20, 24, 39, 58, 45 and 40 cells from 34, 34, 19, 19, 21, 23, 17 and 13 embryos at 4-, 8-, 16-, 32-, 64-, 128-, 256- and 512-cell stages, respectively. l,m, Kymographs of a big and small cell (4- and 128-cell stages, respectively) showing chromosomes (l) and WGA and NER (m). The dashed white line in l represents chromosome velocity. \({v}_{A}\) is the same for both cells, whereas \({v}_{B}\) changes. In c, d, h, i and k, the bins represent the cell stage. In a–g, i and k–m, the error bars represent s.d. In h and j, the error bars represent s.e.m.
