Fig 1: Neurogenic timing-dependent H2B reporter labeling of IO neurons. (a–p) Coronal sections of the IO at approximately 35% (left panel) and 65% (right panel) levels from the caudal edge in eight G2A::H2B mice with tamoxifen injection at different embryonic stages (TM9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5, and 13.0). Signals indicate immunostaining for FoxP2 (red) and H2B reporter labeling (cyan). Subdivisions of the IO are indicated by white lines. Filled and open arrowheads indicate some reporter-labeled neurons with and without FoxP2 labeling, respectively. (q, r) Definition of IO subdivisions shown in drawings of left IO in coronal sections at the two levels. “i”, “l” and “m” indicate the intermediate, lateral and medial subdivisions of some IO subnuclei. (s) Higher magnification of the IO in G2A::H2B mouse with TM10.5. H2B reporter labeling in IO neurons was co-localized with the FoxP2 labeling (white circles). On the contrary, H2B reporter labeling outside the IO was not co-localized with the FoxP2 signal (white squares). The imaged area of (s) is shown in Supplementary Fig. 2 with a square. Created with Adobe Illustrator-10.3, Adobe Photoshop-7.0, and Zen 2.6. See the separate list for abbreviations.