Loss of Itgα5 leads to delays in AV EC migration. (A–G) Phalloidin staining of itga5 WT, heterozygous, and mutant hearts at 58 (A–D) and 80 (E–H) hpf (magenta in overviews [left]; white in magnified AV areas [right]); green, ZO-1; cyan, DAPI. Representative images of hearts and superior AVCs of itga5 WT (A and E), heterozygous (B and F), and mutant (C and G) animals at 58 (A–C) and 80 (E–G) hpf. Categorization of migration stages at 58 hpf (D: +/+, n = 9; +/−, n = 13; −/−, n = 10) and formation of valvular structures at 80 hpf (H: +/+, n = 4; +/−, n = 17; −/−, n = 11). itga5 mutants exhibited delayed AV EC migration at 58 hpf and delayed establishment of valve structure at 80 hpf. Scale bars: (A–C and E–G, left) 20 µm; (right) 10 µm.