Fig. 4. Tshz3 is required for harmonised ureteric peristalisis. (A,B) Cultured ureter of wild-type (A) and Tshz3^lacZ/lacZ (B) embryos. (C,D) Graphs illustrating peristaltic contractions of cultured ureters of wild-type (C) and Tshz3^lacZ/lacZ (D) ureters. Measurements of luminal diameters were made at four different positions from their proximal to distal ends from a 20-second digital recording of contracting ureters (see Movies in the supplementary material). Data are presented as the percentage of the relaxed diameter. In the trace from the wild-type ureter (C), the contraction (downward motion from baseline) initiates about one-fifth of the way down (red line) the ureter; this is rapidly followed by both contraction of the more proximal segment (blue line) and also by distal propagation (pink and yellow lines). Null mutant trace (D) shows absent proximal segment contraction together with a variable delay of distal relaxation (pink line). Representative traces are shown for at least five samples from each genotype.