Figure 9. EGR1 expression correlates with expression of other genes in HVC.

The expression of the immediate early genes (A) EGR1 and (B) FOS was substantially variable in each group, indicative of variable amounts of singing behavior prior to sacrifice. Despite this variability, expression of EGR1 and FOS was significantly correlated (C). Expression of EGR1 was also positively correlated with expression of a subclass of the nuclear hormone receptors, including NR4A1 (D), and many other genes, including the transcription-related gene TAF5L (E). Few genes, such as lipid-transporter ABCG1 (F), were negatively correlated with EGR1 expression. The expression of corticotropin releasing hormone binding protein (CRHBP), the gene changed the most in expression in the data set (G), did not significantly co-vary in expression with EGR1 (H) or NR4A1 (I). Expression values for all panels are illustrated relative to the universal reference sample.