jnk1a and jnk1b are required for fluid flow in KV. (A) Schematic showing KV (magenta) at the base of the notochord (grey) and direction of nodal flow (arrow) at 10-14 ss. The notochord was used to define the antero-posterior and left-right axes for subdivision of KV into quadrants. (B-E) Representative bright-field images of wild type (B), MZjnk1a (C), MZjnk1b (D) and MZjnk1a;MZjnk1b KVs (white dotted line), and traces of bead trajectories over time (coloured lines), together with mean bead speed (µm/s) in each quadrant±s.d. (F) Quantification of average bead speed in KV between 10 and 14 ss. MZjnk1a and MZjnk1b mutant embryos have significantly slower average nodal flow compared with wild-type controls. Loss of both jnk1a and jnk1b results in a greater reduction in average speed. (F) Data are median±interquartile range, Kruskal-Wallis test, multiple comparisons. Wild type, n=22 beads across six embryos; MZjnk1a, n=26 beads across four embryos; MZjnk1b, n=23 beads across three embryos; MZjnk1a;MZjnk1b, n=25 beads across four embryos. (B-E) Anterior is upwards; left is leftwards. ns, not significant. *P<0.05, ***P<0.001, ****P<0.0001. AL, anterior left; AR, anterior right; PL, posterior left; PR, posterior right.
|