Sex- and age-dependent changes in relative mRNA levels of Khdrbs2, Nanos2, Rbm48, and Tdrd3 in the developing female (F) and male (M) mouse cortex/hippocampus. Expression of each gene was calculated and expressed relative to the average of neonatal females (0-F as 1-fold). * Indicates a significant difference of gene expression between the sexes (p < 0.05). # indicates a significant difference vs. females at the same age (p < 0.05). A, B, C indicate significant differences between ages (p <0.05).