Fig. 5

Calmodulin 1a and MLCK mediate cell length at the MHBC. (A–C) calm1a gene expression by in situ hybridization. Arrowheads indicate MHBC, and arrows indicate trigeminal ganglia; asterisks indicate otic vesicle. F, forebrain; M, midbrain; H, hindbrain. (D–G′) Confocal images of embryos injected with mGFP and (D, D′) control MO, (E, E′) calm1a MO, (F, F′) MLCK mRNA, or (G, G′) calm1a MO and MLCK mRNA. (D′–G′) Magnification of D–G. Arrowheads indicate the MHBC. Asterisks in D–G indicate cell outlined in D′–G′. (H, I) Cell length quantification at the MHBC and 40 μm outside the MHBC. (J) Representative Western blots for pMRLC in MHB-specific tissue dissected after control MO or calm1a MO injection. (K) pMRLC Western quantification using α-tubulin as a control (n = 5). (L) Proposed signaling pathway for Ca²⁺ regulation of cell length at the MHBC. For statistical analysis, one-way ANOVA with Tukey’s HSD post hoc test was done. **p < 0.01 and *p < 0.05 compared with control, mean ± SEM. Control MO (n = 17; 34 cells), calm1a MO (n = 19; 38 cells), MLCK mRNA (n = 13; 26 cells), and calm1a MO plus MLCK (n = 9; 18 cells). Scale bars, 25 μm.