Figure 4

A. phagocytophilum up-regulates kynurenine aminotransferase (kat) gene in unfed I. scapularis salivary glands. (A) Putative tryptophan metabolism pathway in I. scapularis ticks is shown. Tryptophan pathway was modified to simple format from KEGG pathway: isc00380 for the purpose of this study. Xanthurenate and kynurenate are some of the products from this pathway. Kynurenine aminotransferase, Xanthurenate and Tryptophan are shown in "bold" text. Quantitative PCR analysis showing expression of kat in different developmental stages in uninfected unfed ticks (B) or in the salivary glands (C) of uninfected (UI) and A. phagocytophilum-infected (I) unfed nymphs is shown. Data for larvae samples was obtained from 5–7 pooled ticks. Open circle represents uninfected (UI) and closed circles represents infected (I) ticks. Each circle represents one tick. Expression of kat mRNA was normalized to tick beta-actin. P value from non-paired Student’s t-test is shown.