Figure 2

abcc9 reporter expression in the zebrafish. (A) Expression of TgBAC(abcc9:GAL4FF)^ncv34Tg (green) is selective in capillary pericytes in coronary vessels. abcc9 reporter expression is negative around arteries (arrowhead) but starts after the appearance of several branches (arrows). Dotted area on the ventricle surface facing the pericardial cavity is enlarged at the top. (B) Transverse sectional view of the trunk vessels. In contrast to the brain (Figure 1A) and coronary vessels (Figure 2A), abcc9 is positive in arteriolar VSMC (a), while still being negative in arterial VSMC covering the primary artery (A) or the dorsal aorta (not shown in this image). Interestingly, the expression of abcc9 is lower in veins (v) than in arterioles or capillaries, which is also in clear contrast to the brain vasculature, suggesting that abcc9 expression reflects organotypic differences among mural cells. (C) Observation of the TgBAC(abcc9:GAL4FF)^ncv34Tg reporter (green) around the vasculature in the ventral head at 72 hpf (left) or 144 hpf (right) indicates that mural cells covering the ventral artery and aortic arches are negative for abcc9, which is similar to the findings in the dorsal aorta. Dotted area in the right image is enlarged on the left. Scale bars: 50 μm (A), 200 μm (B), 30 μm (C, 72 hpf), 50 μm (C, 144 hpf).