Fig. 6

Progesterone effect on YCL microtubule organization and growth dynamics. (a) Images of live wild-type embryos treated from 2 hpf onward with progesterone (50 µM, lower row), and DMSO controls (upper row), photographed at indicated stages. Arrowheads: blastoderm margin. Scale bar 100 µm. (b) Quantification of epiboly progression. P4 – progesterone. Error bars - SD, ** p<0.005, Mann-Whitney test). (c) Anti-β-tubulin immunostaining images of the marginal region of wild-type DMSO control and 50 µM progesterone treated embryos fixed at indicated stages. Arrows mark microtubule accumulation around the MTOCs and increased density of microtubule bundles. Asterisk marks disorganized YCL microtubule network with microtubule free patch. Scale bar 50 µm. (d) Quantification of progesterone (P4) induced yolk cell microtubule network organization defects. Phenotypic classes see text for details. (e, f) Microtubule growth rates (e) and track velocity distribution (f) at sphere stage for DMSO control and progesterone (P4) treated wild-type embryos. Error bars - SEM, embryo numbers shown in (g). (g) Average track speed for DMSO control and progesterone treated wild-type embryos at indicated stages. Error bars indicate SEM (* p<0.05, Mann-Whitney test; at 60% epiboly NS). (h) Quantification of track bending in DMSO control and progesterone treated embryos at sphere stage, n as in (6 g). (i) Average numbers of EB3-mCherry tracks per time series at indicated stages of DSMO control or progesterone (P4) treated wild-type embryos. Error bars - SD. (*p<0.05; ** p<0.005; Mann-Whitney test; n as in 6 g).