Host adiponectin significantly increases tick HBP expression.

(A) No interaction of adiponectin with B. burgdorferi was identified, as analyzed by flow cytometry. PGLYRP1 was used as positive control. The background of Alexa Fluor 488-His antibody alone with B. burgdorferi is shown in gray. (B) Mouse adiponectin has no effect on B. burgdorferi viability as determined by BacTiter-Glo assay. (C) RNA-seq of ticks feeding on WT (n = 3) and KO mice (n = 3). The ticks that fed on the same mouse were pooled for RNA extraction. (D) GO enrichment analysis of transcriptome data from the ticks feeding on WT (n = 3) and KO mice (n = 3). The second level GO terms were shown in the plot and enrichment analysis was performed using the functional annotation tool DAVID. (E) Volcano plot of differentially expressed genes between the ticks feeding on WT (n = 3) and KO mice (n = 3). The Top 3 genes were highlighted by orange color. The gene names can be found in S1 Table. (F) qPCR validation of HBP gene expression in SGs and MG of the ticks feeding on WT (n = 3) and KO mice (n = 3). The ticks feeding on different mice were collected for analysis. For all the data, each dot represents one biological replicate. Statistical significance was assessed using a nonparametric Mann–Whitney test (*p p > 0.05). Data underlying this figure can be found in S1 Data. We would like to acknowledge that figures were created using BioRender (https://www.biorender.com/) with permission. GO, Gene Ontology; HBP, histamine-binding protein; KO, knock out; MG, midgut; PGLYRP1, peptidoglycan recognition protein 1; qPCR, quantitative real-time PCR; SG, salivary gland; WT, wild-type.