title: Multiple ferritins are vital to successful blood feeding and reproduction of the hard tick Haemaphysalis longicornis.
abstract: Ticks are obligate hematophagous parasites and important vectors of diseases. The large amount of blood they consume contains great quantities of iron, an essential but also toxic element. The function of ferritin, an iron storage protein, and iron metabolism in ticks need to be further elucidated. Here, we investigated the function a newly identified secreted ferritin from the hard tick Haemaphysalis longicornis (HlFER2), together with the previously identified intracellular ferritin (HlFER1). Recombinant ferritins, expressed in Escherichia coli, were used for anti-serum preparation and were also assayed for iron-binding activity. RT-PCR and western blot analyses of different organs and developmental stages of the tick during blood feeding were performed. The localization of ferritins in different organs was demonstrated through an indirect immunofluorescent antibody test. RNA interference (RNAi) was performed to evaluate the importance of ferritin in blood feeding and reproduction of ticks. The midgut was also examined after RNAi using light and transmission electron microscopy. RT-PCR showed differences in gene expression in some organs and developmental stages. Interestingly, only HlFER2 was detected in the ovary during oviposition and in the egg despite the low mRNA transcript. RNAi induced a reduction in post-blood meal body weight, high mortality and decreased fecundity. The expression of vitellogenin genes was affected by silencing of ferritin. Abnormalities in digestive cells, including disrupted microvilli, and alteration of digestive activity were also observed. Taken altogether, our results show that the iron storage and protective functions of ferritin are crucial to successful blood feeding and reproduction of H. longicornis.
authors: Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
authors: Remil Linggatong
authors: RL
authors: Galay
authors: Kyaw Min
authors: KM
authors: Aung
authors: Rika
authors: R
authors: Umemiya-Shirafuji
authors: Hiroki
authors: H
authors: Maeda
authors: Tomohide
authors: T
authors: Matsuo
authors: Hiroaki
authors: H
authors: Kawaguchi
authors: Noriaki
authors: N
authors: Miyoshi
authors: Hiroshi
authors: H
authors: Suzuki
authors: Xuenan
authors: X
authors: Xuan
authors: Masami
authors: M
authors: Mochizuki
authors: Kozo
authors: K
authors: Fujisaki
authors: Tetsuya
authors: T
authors: Tanaka
mesh_terms: D000818:Animals; D015153:Blotting, Western; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005293:Ferritins / Q000235:genetics / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D041981:Gastrointestinal Tract / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D007106:Immune Sera / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D026863:Ixodidae / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D009928:Organ Specificity / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015203:Reproducibility of Results; D012098:Reproduction / Q000502:physiology; D016019:Survival Analysis; D014819:Vitellogenins / Q000235:genetics / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D007106:Immune Sera; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014819:Vitellogenins; D005293:Ferritins; D007501:Iron
keywords: RNA interference; ferritin; iron; ticks