Consistent with previous findings13,14, we found that the largest differences were attributable to Y chromosome genes, especially PCDH11Y, RPS4Y1, USP9Y, DDX3Y, NLGN4Y, UTY, EIF1AY, and ZFY, which displayed constant expression across regions and periods, with the exception of PCDH11Y down-regulation in the postnatal CBC (Fig. 2b). Interestingly, the functional homologues of these genes on the X chromosome (PCDH11X, RPS4X, USP9X, DDX3X, NLGN4X, UTX, and EIF1AX), except ZFX during fetal development, were not up-regulated in a compensatory manner in female brains (Supplementary Fig. 17).
