Fig. 5: Astakine (astk) promotes hemocyte proliferation and differentiation in I. scapularis.
From: Tick hemocytes have a pleiotropic role in microbial infection and arthropod fitness
a Total hemocyte counts in the hemolymph of unfed I. scapularis nymphs subjected to microinjection with increasing amounts of rAstk (orange) or BSA (grey) as a control (n = 21, 14, 14 and 24). b Percentage of hemocyte morphotypes (prohemocytes, plasmatocytes and granulocytes; n = 10 and 10 in all cases) in the hemolymph of unfed nymphs following microinjection with 5 ng rAstk (orange) compared to BSA controls (grey). c–h Ticks were subjected to microinjection with astk siRNA (si-astk; blue) or scrambled RNA (sc-astk; grey) and subsequently fed on either (c–g) uninfected or (h) A. phagocytophilum-infected mice. c Efficacy of astk silencing (n = 20 and 16), (d) total number of hemocytes (n = 9 and 8) and (e) percentage of hemocyte morphotypes in individual ticks (n = 12 and 10 in all cases). f Weight measurements of engorged nymphs (n = 29 and 19). g Percentage of nymphs that molted to adults. h RT-qPCR assessment of astk silencing efficiency (n = 16 and 15) and A. phagocytophilum load (n = 18 and 14) in individual infected ticks. Bacterial quantification was based on the expression of A. phagocytophilum 16 s rRNA (Ap16S) gene. Results are represented as (a–f, h) mean ± SD or as (g) a percentage from the total. A minimum of two independent experiments were conducted. Statistical significance was evaluated by (a) one-way ANOVA with Dunnett’s multiple comparisons test; (b–f, h) an unpaired two-tailed t test with Welch’s correction or (g) by a Fisher exact test, and significant p-values (< 0.05) are displayed in the figure. Source data are provided as a Source Data file. rAstk = recombinant astakine; BSA = bovine serum albumin.
