Figure 2

Darkfield images from in situ hybridization depicting sexually dimorphic mRNA expression for CK303566in the zebra finch song system at day 25 post-hatching. Arrows delineate borders of song regions. This gene showed the most extensive sex differences in expression. In lMAN (lateral magnocellular nucleus of the anterior nidopallium) males (A) show higher levels of mRNA expression (i.e. higher densities of silver grains) than do females (B). Similar differences were obtained in the portion of the medial striatum which contains area X in males (C), although area X is not morphologically distinct in females (D), and in RA (robust nucleus of the arcopallium, panels E = males, F = females). However, in HVC, no specific labeling was detected in either sex (panel G = male, panel H = female). Scale bar = 200 μm for lMAN and area X; 100 μm for HVC and RA.