Figure 5. Dae2^Is-Dependent Effects on I. scapularis Ticks during a Bloodmeal.

(A) Schematic of in vivo dae2^Is knockdown and immunization experiment. Mice were injected with sterile saline control (gray) or 2.5 mg rabbit αDae2^Is antibody and I. scapularis nymphs were microinjected with small interfering RNAs (siRNAs) targeting dae2^Is (red) or scrambled controls (gray). After 24 h of recovery, dae2^Is and control ticks were placed on αDae2^Is antibody immunized mice or control mice, respectively. Ticks were forcibly detached at 3 days post-host attachment and assessed by qPCR, scutal index, and weight.

(B) Western blot analysis against recombinant Dae2^Is using serum collected from control (left) and αDae2^Is-immunized (right) mice at 18 days following antibody injection. A secondary αRabbit antibody was used to specifically detect rabbit αDae2^Is antibodies the mice were immunized with. αDae2^Is was used as a control (far left).

(C) Staphylococcus load was detected in DNA isolated from pooled dae2^Is knockdown (red) or control ticks (black) by qPCR with primers designed to target all species from the genus Staphylococcus. Results are presented as the average log₂ Staphylococcus per tick.

(D) Diagram of how scutal index (SI) changes during feeding. Scutal index is the ratio of the length of the entire tick body to the width of the scutum (Meiners et al., 2006).

(E and F) Scutal index (E) and tick weight (F) of individual ticks are shown. *p < 0.05 based on Student’s t test. Blinded measurements were made from tick images using ImageJ. Weight was measured with an analytical balance with an error of ±0.1 mg.