Fig. 4

HlVgR-knockdown by RNA interference (RNAi) in H. longicornis. a, c Total RNA was purified from engorged ticks in each group. The gene silencing of HlVgR was assessed by real-time PCR. The HlVgR expression was normalized to the HlP0 mRNA expression. Data represent the mean ± SD of triplicate samples. HlVgR mRNA expressions of RNAi-treated ticks (HlVgR RNAi) were significantly lower than those of control ticks (Control) at both engorgement (a) and at 5 days after engorgement (c) (*P < 0.01; Welchʼs t-test). b, d Phenotypes of the ovaries of HlVgR RNAi-treated and control ticks. Note that HlVgR-knockdown caused delayed development in the oocytes at both engorgement (b) and at 5 days after engorgement (d). Abbreviations: I, stage I oocyte; II, stage II oocyte; III, stage III oocyte; IV, stage IV oocyte; V, stage V oocyte. Scale-bars: b, 1 mm for ovaries and 100 µm for ovarian sections; d, 2 mm for ovaries, and 200 µm for ovarian sections