Artery maturation is attenuated in tnnt2a morphants. Expression of dll4 (A-D) or ephrinB2 (E,F) in the dorsal aorta in control MO and tnnt2aMO-injected embryos at 24 and 36 hpf, respectively. Anterior is to the left and dorsal is up. (G-H) Transverse section of control MO (G) and tnnt2aMO (H) injected fli1a:GFP embryos at 36 hpf. White dotted line denotes dorsal aorta; red dotted line denotes cardinal vein. (I-J) Quantitative RT-PCR analysis of dll4 expression in the dissected trunk region of control and tnnt2aMO embryos at 24 and 36 hpf, respectively (mean ± SD, t test, *P < .05, n = 3).