||FIG. 5. c~-SM actin expression on transversal sections of control and mutated Xenopus embryos at stage 47. In control embryos, a-SM actin
expression covers each loop of the intestine (arrowheads); the SM cells of the lungs and the aorta are also stained (A, D); heart is negative (F).
Mutated embryos present an expression of a-SM actin in the outer layer of the incompletely differentiated intestine (arrowheads), the lumen of
which is still full of yolk (B, C, E); the SM cells of lungs and the aorta are also expressed a-SM actin (E); heart is negative (G). a, aorta; h, heart;
b, brain; n, notochord; 1, lung. Scale bar in A, B, C, F, and G, 0.3 mm; scale bar in D and E, 0.6 ram.