We next examined whether the marked variation in Per3 expression has an impact on putative downstream phenotypes. We carried out covariance analyses of PC1 of the three probe sets (1421087_at, 1460662_at and 1421086_at) with an extensive database of BXD phenotypes to identify traits that are strongly linked with variation in Per3 transcript abundance. The first component of Per3 expression is significantly correlated with five anxiety-related behaviors and five ethanol-responsive traits (P<0.05; Figure 4; Supplementary Table S4). Each of these 10 behavioral traits was assayed by different research groups using independent BXD cohorts and highlights a robust correlation between Per3 and anxiety- and alcohol-related traits.
