Effect of <i>Tudor-SN</i> knockdown on tick feeding.

<p>(A) <i>Tudor-SN</i> mRNA levels were analyzed using RNA extracted from <i>I</i>. <i>scapularis</i> eggs (three batches of approximately 500 eggs each), fed and unfed larvae (three pools of 50 larvae each), fed and unfed nymphs (three pools of 15 nymphs each), and fed and unfed male and female adult tick tissues (4 ticks each) by real-time RT-PCR and normalizing against tick <i>cyclophilin</i> and <i>ribosomal protein S4</i>. Normalized Ct values were compared between unfed and fed ticks by Student's t-test with unequal variance (*P<0.05). (B) <i>Tudor-SN</i> mRNA levels in <i>I</i>. <i>ricinus</i> ticks during tick feeding. <i>Tudor-SN</i> mRNA levels were determined by real-time RT-PCR in the guts and salivary glands of uninfected female ticks (N = 10 ticks for each time point) fed on mice for 0 (unfed ticks), 1, 3 and 5 days. <i>Tudor-SN</i> Ct values normalized against tick <i>16S rRNA</i> are shown in arbitrary units (Ave±SD) and were compared between Days 0–3 and Day 5 by Student's t-test with unequal variance (*P<0.05). (C) <i>I</i>. <i>scapularis</i> female ticks were injected with dsRNA and fed on sheep. Tick weights (Ave+SD) were compared between groups by Student's t-test with unequal variance (*P<0.05; N = 20 ticks per group). Panels show representative images at day 5 of tick feeding.