Fig. 2. Diminished length and increased width of Lp/Lp embryos. (A) Embryonic length and width as measured on photomicrographs of cultured embryos viewed from the dorsal surface, after removal of yolk sac and amnion. (B-E) Length and width measurements of embryos cultured in the absence (B,C) or presence (D,E) of the ROCK inhibitor Y27632. Each data point represents a single embryo. Linear regression lines are shown. Embryonic length increases significantly with somite number in both absence (B) and presence (D) of inhibitor (two-way ANOVA; P<0.001). Length also varies significantly with genotype (+/+>Lp/Lp) in embryos cultured in the absence (B) of inhibitor (P=0.008), whereas in the presence of inhibitor (D) embryonic length no longer varies significantly with genotype (P=0.053). Embryonic width does not vary significantly with somite number either in the absence (C) or presence (E) of inhibitor (P>0.05). Whereas embryonic width varies significantly between genotypes (Lp/Lp>+/+) in the absence of inhibitor (P=0.006), there is no significant variation between genotypes in the presence of inhibitor (P>0.05). Embryonic width is significantly greater in the presence of inhibitor (E) than in its absence (C), irrespective of genotype (P<0.001), whereas embryonic length does not differ in the presence (D) or absence (B) of inhibitor (P>0.05). Number of embryos measured in absence or presence of Y27632 is: +/+: 35,16; Lp/+: 56,25; Lp/Lp: 28,11.