Figure 2.

Phenotypes by PNU‐74654. Alcian blue‐stained chick embryos at Hamburger and Hamilton (HH) stage 32–33 (A–C and E–G) and Alcian blue plus Alizarin red‐stained 35‐36 (D,H), dorsal view. Red arrows and arrowheads indicate the phenotype. Beads are highlighted in yellow. The right column (A’–H’) shows higher magnifications of the phenotypic area, with dotted lines indicating missing rib parts. Beads are highlighted in yellow in low magnification figures where possible. Scale bar, 1 mm. (A) Shaft defect of fourth right rib. Beads are noted in the plane of the second and fourth right ribs. (B) Shaft defect of seventh left rib. Asterisk indicates mechanical damage to seventh right rib. (C) Large posterior shaft defect of fifth left rib. (D) Large posterior shaft defect on the third right rib. The proximal part of the third rib is seen adjacent to the vertebral body and translucent tissue is seen in the gap in situ. (E) Bilateral missing seventh ribs and small proximal defect of third right rib (arrows). Some ectopic cartilage deposition is noted in the fifth left and right ribs. A bead is noted medial to the third right rib head. (F) Missing seventh ribs bilaterally and proximal defect of the fifth left rib. The fourth left and right ribs are malformed and there is bifurcation of the third right rib. (G) Proximal defect of fourth rib. (H) Missing sixth right rib.