Fig. 1: Volumes and fluxes in the C. elegans gonad.
From: A hydraulic instability drives the cell death decision in the nematode germline
a, Top: schematic of an adult hermaphrodite gonad arm. Bottom: representative fluorescence image of a gonad expressing the membrane marker mCherry::PH(PLC1delta1). b, Top: germ cells colour-coded according to cell volume. Bottom: germ cell volume V along the gonad from distal tip (0% length) to proximal turn (100% length), for 5,265 germ cells from 18 gonad arms (bottom). Inset: s.d. plotted against the average of germ cell volumes determined at 40 colour-coded positions along the gonad. We observe two different relationships between s.d. and average, indicative of a transition between two growth modes. c, Top: cross-section of a gonad expressing LifeAct::mKate overlaid with colour-coded flow speeds as obtained by PIV (Supplementary Information). Bottom: cytoplasmic flux Qr through the rachis as a function of position along the gonad. Open circles, Qr determined from PIV speed distributions obtained from 10 gonad arms. Solid line, best parameter theory fit given the profile of material uptake S shown in d. d, Open circles denote material uptake S into the gonad from the outside, determined by volume conservation of rachis flux (c) and volume flux associated with germ cells moving from distal to proximal (Supplementary Fig. 1e). The thick dashed line shows a smoothened representation of the material uptake profile (Supplementary Information). Inset: green arrows indicate material uptake from the surrounding. The dashed vertical lines and grey boxes in b–d denote the position and associated confidence interval, respectively, where the distribution of germ cell volumes is no longer unimodal. Scale bars, 20 μm. Error bars indicate the error of the mean at 95% confidence.
