Brain subdivision gene expression profiles across avian species. A:
FOXP1 expression in pigeon, mid-sagittal section, labeling the mesopallial subdivisions and striatum. B:
FOXP1 expression in Japanese quail, medial section. C:
FOXP1 expression in budgerigar brain, mid-sagittal section. D:
FOXP1 expression in song sparrow, mid-sagittal section. E:
FOXP1 expression in Anna’s hummingbird, mid-sagittal section. F:
COUP-TF2 expression in pigeon, medial section, labeling the nidopallium. G,H:
ROR-b expression in adjacent medial section (G) and a lateral section (H) of pigeon brain, labeling the intercalated nidopallium regions (L2, E, and B). I:
ER81 expression in pigeon brain, far lateral section, labeling the arcopallium. Scale bar = 1 mm.