Figure 4. Dae2^Is Is Found in Tick Saliva and Upregulated during Feeding.

(A) Schematic of the tick at the bite-site interface showing the salivary glands. The salivary glands produce the saliva that is injected into the host.

(B) Cartoon representation of salivary gland acini. Nuclei (blue), vesicles (red), and saliva flow routes (gray arrows) are shown.

(C–F) Confocal images of dissected I. scapularis salivary glands from adult females. Whole mounts were stained with DAPI (left panels, blue). Control mounts (C and D) were immunostained with rabbit antibody raised against a the bacterial Tae1^Pa toxin (αTae1^Pa). Experimental mounts (E and F) were immunostained with rabbit αDae2^Is. Merged images are shown (right). Scale bars, 15 μm. Selected acini are marked (dashed white lines). A zoomed-in region is shown (box).

(G) Diagram of the dae2^Is gene structure showing the predicted N-terminal signal sequence from nucleotide position 1–33 (blue).

(H) Western blot of collected saliva from partially fed I. scapularis adult females demonstrating presence of Dae2^Is in saliva. First lane has recombinant Dae2^Is as a positive control for rabbit αDae2^Is reactivity.

(I) Western blot showing reactivity of mouse serum to Dae2^Is. Recombinant Dae2^Is protein was probed with mouse serum before (uninfested) or after I. scapularis feeding (infested). Rabbit αDae2^Is was used as positive control for reactivity (first lane).

(J) dae2^Is expression (normalized against actin^Is transcripts) before (unfed) and after feeding (fed) on mice for nymph and adult ticks. *p < 0.05, **p < 0.01.

See also Figure S5.