Fig. 1.

Abnormal primordium patterning leads to loss of terminal neuromasts in the lef1^nl2 mutant. (A,B) eya1 expression in the pLL of wild-type sibling and lef1^nl2 mutant embryos at 2 dpf. The lef1^nl2 mutant lacks a tc. (A′,B′) Distal limit of eya1 expression in wild-type and lef1^nl2 mutant (arrow) embryos. (C) Average number of NMs (excluding tc) in lef1^nl2 mutant and wild-type sibs (mean±s.d.) are not significantly different at 2 dpf (n=28 wild type, 11 lef1^nl2, P=0.49, Student's t-test). (D) Axial positions of L1-L5 in lef1^nl2 and wild-type siblings at 2 dpf (mean±s.d.). The axial level of stalled primordium (prim) in lef1^nl2 mutants is indicated by the pink bar. Position of L1-L5 is significantly shifted anteriorly in lef1^nl2 mutants (n=18, P<0.001, two-way ANOVA with replication). (E-F′′) Stills from time-lapse movies of primordium migration in wild-type sibling and lef1^nl2 mutant embryos that express the Tg(–8.0cldnb:lynGFP) transgene. Wild-type and lef1^nl2 embryos were imaged beginning at 34 hpf for 780 minutes and 840 minutes, respectively (see Movies 1 and 2 in the supplementary material). (E-E′′) Over the course of 780 minutes, the primordium in the wild-type embryo migrated out of frame, deposited three NMs (red, blue and yellow asterisks) and generated two new rosettes (green and pink asterisks). (F-F′′′) Over the course of 840 minutes, the primordium in the lef1^nl2 mutant has slowed and became elongated (pink asterisk), having deposited four NMs (red, blue, yellow and green asterisks). Scale bars: 20 μm.