A. phagocytophilum–induced actin phosphorylation selectively regulates I. scapularis salp16 gene expression. Q-RT-PCR results showing the levels of salp16 or salp20 in ipak1-dsRNA– (A and C), PK-18– (PAK1 inhibitor), or Genistein (tyrosine kinase inhibitor)-injected ticks, respectively (B and D). Mock controls were injected with buffer alone (A and C) or DMSO (B and D), respectively. The levels of salp16 or salp20 transcripts were quantified against tick β-actin transcripts. Each circle represents an individual tick. Statistics were performed using a Student’s t test and the p-value is shown. Horizontal bars in A–D indicate mean values of the data points. (E and F) EMSAs performed with the biotin-labeled salp16 (E) or salp20 (F) promoter TATA-binding regions and uninfected or A. phagocytophilum–infected nuclear extract proteins. Shifts and the salp16- or salp20-free probes are indicated with arrows. Representative gel images from three independent experiments are shown. Wedges indicate increasing amounts of nuclear extracts (1, 1.5, 2, and 2.5 µg).