library_construction_protocol: The Ixodes scapularis ticks used in this study were obtained from the tick-rearing facility at Oklahoma State University (Stillwater, OK, USA). Prior to infestation, unfed ticks were maintained at 21°C and 85% relative humidity. One day before feeding, female ticks were paired with males to allow mating. Adult ticks were placed on the outer ear of four naïve female New Zealand rabbits, restricted by orthopedic stockinets that were glued in place. A total of 20 female and 20 male ticks (40 ticks per ear, 80 ticks per rabbit) were allowed to attach. To classify ticks by blood-feeding index, partially fed ticks were collected from the host based on engorgement size, sorted by weight, and divided into biological triplicates: an unfed group (UF) (15 females per replicate, weighing 1.6 mg in average), group G2 (5 females per replicate, weighing 7.2 mg in average), and group G5 (4 females per replicate, weighting 41.5 mg in average). After removal from the host, ticks were rinsed sequentially with 1% bleach, nuclease-free water, 70% ethanol, and a final rinse with nuclease-free water. Ticks were dissected within two hours of removal. Salivary glands (SGs) were isolated and stored in fresh, ice-cold, nuclease-free HBSS buffer (Invitrogen, Carlsbad, CA, USA). To prepare a single-cell suspension, the salivary glands were dissociated following a mechanical and enzymatic protocol. The resulting cell suspension was filtered through a 40 µm Flowmi cell strainer and centrifuged at 600 rcf for five minutes to pellet the cells. The pellet was then resuspended in an appropriate volume of HBSS media to achieve the target cell concentration. Cell counting and viability were assessed using trypan blue staining and a Neubauer chamber for visualization. The single cell suspensions were loaded (7,000 cells) onto a Chromium Controller for GEM (Gel Bead-In-EMulsion) generation in triplicate for three groups and barcoding using the Chromium Single Cell 3' Reagent Kits according to the manufacturer's protocol (10x Genomics). After cDNA synthesis, amplification, and library construction, the libraries were sequenced by the Illumina NovaSeq 6000 System.