26 research outputs found

    Deterministic Simulations of a Chain of Oscillators Corresponding to the Model Sketched in Figure 1 (See Table 1 for Values of Parameters)

    No full text
    <p>Waves of expression spread from posterior to anterior PSM (A–C), as observed experimentally. To test the effect of oscillator-coupling through DeltaC-Notch signaling, a perturbation was induced by delaying a number of oscillators in the chain by 5 min (D). After 1.3 h, the resulting perturbations in the spatial pattern were reduced (E); note that cells corresponding to indexes smaller than 13 on the <i>x</i>-axis should show no perturbation, because they were added to the chain after the initial perturbation.</p

    Stochastic Simulations of a Chain of Oscillators Corresponding to the Model Sketched in Figure 1, with Normal Coupling through Delta-Notch Signaling (A–C) and with Disrupted Coupling (D–F)

    No full text
    <p>When coupling was absent, some cells were noticeably out of synchrony with their neighbors (arrowheads), and local synchrony was not as strong. The transcription rate of <i>her1</i> and <i>her7</i> was increased in (D–F) to make up for the loss of Notch signaling.</p

    Simulated Grafting of an FGF-8 Coated Bead (Star)

    No full text
    <p><i>her13.2</i> mRNA was assumed to be ectopically expressed, at the same level as in posterior PSM, in an area centered around the bead and marked by arrows.</p

    Numerical Simulations of the Model Sketched in Figure 1, without DeltaC (See Table 1 for Values of Parameters)

    No full text
    <p>Overlay of deterministic and stochastic simulation results (A) and deterministic simulation results with various simulated knockdowns (B).</p

    Simulated Translation Knockdown of <i>her1</i> (A), <i>her7</i> (B), and Combined <i>her1</i> and <i>her7</i> (C)

    No full text
    <p>For single knockdowns, residual oscillations of diminished relative amplitude were observed, and stripe formation in anterior PSM was disrupted. For the combined knockdown, <i>her1</i> and <i>her7</i> were upregulated and did not oscillate in posterior PSM, but did oscillate in a salt-and-pepper pattern in anterior PSM.</p

    Starvation delays reproductive senescence.

    No full text
    <p>(A) Schematic of starvation experiment. (B) Phalloidin-stained fog-2 gonads before and after starvation. Scale bar: 25 ÎĽm. (C) Total brood size for <i>fog-2</i> females mated after 2 days of starvation or control treatment. For statistical tests see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s008" target="_blank">S2C Table</a>. (D) Reproductive capacity retained by <i>fog-2</i> females after 2-day starvation or control treatment (computed by dividing numbers used in C by reproductive capacity at day 0). Error bars represent 83% confidence intervals; asterisks indicate significance of Wilcoxon rank sum test p-value.</p

    Slower average cell cycle progression and loss of synchrony in gonads with reduced reproductive activity.

    No full text
    <p>(A, B) Principle of EdU pulse chase analysis. Three fictitious mitotic zones cycle steadily (A) or stochastically enter a dormant state (B; play and pause symbols within the squares). The position of each square on the circle represents mitotic zone cell cycle progression (progression from time of labeling highlighted by a colored band). A full revolution on the circle corresponds to all cells in the mitotic zone having undergone a full cycle. The red wedge in the bottom row shows average cycle progression (angle shown by red arrows) and the amount of dispersion between mitotic zones (width of the wedge, set to the inverse of the magnitude of the resultant computed as the vector sum of individual gonad positions). (C) Analysis of cell cycle progression after EdU pulse-chase. Mitotic zones from virgin females or old wild-type hermaphrodites lose synchrony at later chase times, as shown e.g. by wider wedges (virgin fog-2 data is repeated in rows 2 and 3 to facilitate comparisons). See also <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s005" target="_blank">S5 Fig</a>, <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s011" target="_blank">S5 Table</a>, <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s016" target="_blank">S1 Movie</a>, <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s015" target="_blank">S1 Dataset</a> and <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s017" target="_blank">S1 Text</a>.</p

    DDR increases with past reproductive activity and curtails reproductive capacity.

    No full text
    <p>(A) Average number of RPA-1::YFP foci per nucleus in late pachytene. Image panels show example RPA-1 foci (arrows; YFP: green; DNA: red). Scale bars: 2.5 μm. For statistical tests see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s010" target="_blank">S4A Table</a>. (B) Total brood size is larger for mated hus-1(op241) (red bar) than for mated wild-type (blue bar). For statistical tests see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s010" target="_blank">S4B Table</a>. Error bars represent 83% confidence intervals; asterisks indicate significance of Wilcoxon rank sum test p‑value. To test whether the DDR curtails reproductive activity, we utilized the <i>hus-1</i> reduction of function allele <i>op241</i>. This mutation abrogates multiple forms of DDR [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.ref030" target="_blank">30</a>] but preserves normal reproductive activity in selfed worms [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.ref031" target="_blank">31</a>]. Mated <i>hus-1(op241)</i> hermaphrodites had a significantly larger brood size than wild-type controls (<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1005985#pgen.1005985.s010" target="_blank">S4B Table</a> and Fig 4B); the reproductive schedule was almost identical between days 1 and 3, but from day 4 onward <i>op241</i> had a ~1.5-fold greater number of progeny. This shows that the DDR hastens reproductive senescence, by a mechanism that remains to be identified.</p

    Mitotic zones in gonads with reduced reproductive activity intermittently occupy a dormant state.

    No full text
    <p>(A) Representative z-projection images of continuous EdU labeling of wild-type and fog-1 (DNA: red; EdU: green). “Dormant” mitotic zones are defined by the absence of any EdU positive cell, and are marked with an asterisk. Almost all wild-type mitotic zones show activity within 1 h of continuous labeling, whereas fog-1 mitotic zones take in excess of 6 h to all have experienced activity. (B) Fractions of day 1 mitotic zones remaining unlabeled as a function of time on EdU-labeled food (n = 40–82 for each genotype and time point).</p
    corecore