Figure S4.
Objects larger than a few micrometers are biased in their diffusion. (A) Images of fluorescent aggregates of beads (left panel) and an oil droplet in prophase I oocytes (right panel). Aggregates of beads correspond to objects with diameters between 100 nm and 2 µm. Oil droplets correspond to objects between 5 and 30 µm in diameter. The oocyte nucleus is 25 µm wide. Scale bars are 10 µm. (B) Cumulative bias of the particle centroid motion for particles of varying diameters. Black dots represent the particle cumulative bias toward the center and black diamonds toward the cortex. For 0–0.5-µm particles, it was calculated from n = 185 trajectories. For 0.5–1-µm particles, it was calculated from n = 445 trajectories. For 1–1.5-µm particles, it was calculated from n = 112 trajectories. For 1.5–2-µm particles, it was calculated from only n = 13 trajectories. The gray area on all panels represents the numerically constructed 99% confidence interval (CI) of cumulative bias values for the same number and same size of object as the experimental one and presenting a random motion (see Materials and methods). The cumulative bias outside these intervals is likely generated by directionally biased motion (P value of 0.01). (C) Scheme explaining how the mean radial instantaneous velocity of object centroid is measured. The black dots correspond to the centroid of objects. One track of an oil droplet centroid is presented with the directionality of motion depicted by an arrow for each time step. The nucleus is in blue. (D) Mean radial instantaneous velocity as a function of object size. The velocity is computed from the distribution of d.cos(θ) at 5Δt (2.5 s). The P value is the probability that the distribution is significantly different from a normal distribution with the same standard deviation and centered at 0 (result of a z-test). For objects <1 µm, there is no bias toward the center. For objects >1 µm, there is a significant bias toward the oocyte center. n = 5 oocytes for aggregates of particles, and n = 29 oocytes for oil droplets. As presented on the figure (from left to right), the P values are: 0.17 (ns); 0.08 (ns); 0.039 (*); 0.032 (*); 4.9 × 10−11 (****), and 0.1 (ns). ns, not significant.

Objects larger than a few micrometers are biased in their diffusion. (A) Images of fluorescent aggregates of beads (left panel) and an oil droplet in prophase I oocytes (right panel). Aggregates of beads correspond to objects with diameters between 100 nm and 2 µm. Oil droplets correspond to objects between 5 and 30 µm in diameter. The oocyte nucleus is 25 µm wide. Scale bars are 10 µm. (B) Cumulative bias of the particle centroid motion for particles of varying diameters. Black dots represent the particle cumulative bias toward the center and black diamonds toward the cortex. For 0–0.5-µm particles, it was calculated from n = 185 trajectories. For 0.5–1-µm particles, it was calculated from n = 445 trajectories. For 1–1.5-µm particles, it was calculated from n = 112 trajectories. For 1.5–2-µm particles, it was calculated from only n = 13 trajectories. The gray area on all panels represents the numerically constructed 99% confidence interval (CI) of cumulative bias values for the same number and same size of object as the experimental one and presenting a random motion (see Materials and methods). The cumulative bias outside these intervals is likely generated by directionally biased motion (P value of 0.01). (C) Scheme explaining how the mean radial instantaneous velocity of object centroid is measured. The black dots correspond to the centroid of objects. One track of an oil droplet centroid is presented with the directionality of motion depicted by an arrow for each time step. The nucleus is in blue. (D) Mean radial instantaneous velocity as a function of object size. The velocity is computed from the distribution of d.cos(θ) at 5Δt (2.5 s). The P value is the probability that the distribution is significantly different from a normal distribution with the same standard deviation and centered at 0 (result of a z-test). For objects <1 µm, there is no bias toward the center. For objects >1 µm, there is a significant bias toward the oocyte center. n = 5 oocytes for aggregates of particles, and n = 29 oocytes for oil droplets. As presented on the figure (from left to right), the P values are: 0.17 (ns); 0.08 (ns); 0.039 (*); 0.032 (*); 4.9 × 10−11 (****), and 0.1 (ns). ns, not significant.

This Feature Is Available To Subscribers Only

or Create an Account

Close Modal
Close Modal