Fig. 1

Reductase expression in the spinal cord of golden-collared manakins (left column; n = 7 male, n = 5 female) and zebra finches (right column; n = 6 male, n = 5 female). Regions of the spinal cord are denoted on the bottom axis. a, b Relative expression of the gene for type 1 5α-reductase. c, d Relative expression of the gene for type 2 5α-reductase. e, f Relative expression of the gene for 5β-reductase. Data are presented as mean ± 1SEM. Asterisks (*) denote significant differences (p < 0.05) in relative expression between sexes (depicted in legend). N.S indicates non-significant difference (p > 0.05)