Konnai Satoru, Saito Yoichi, Nishikado Hideto, Yamada Shinji, Imamura Saiki, Mori Akina, Ito Takuya, Onuma Misao, Ohashi Kazuhiko
Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
Jpn J Vet Res. 2008 Jan;55(2-3):85-92.
Ixodes persulcatus Schulze (I. persulcatus) is distributed in Russia and Far East Asia including Japan, and has been implicated as the vector of several human pathogens. In particular, I. persulcatus acts as the only tick vector for human lyme borreliosis in Japan. In order to elucidate the mechanism of transmission of I. persulcatus-borne pathogens, we developed a laboratory colony of I. persulcatus. Ticks were fed on Syrian hamster and engorged ticks that had dropped off the animals were collected and maintained to allow them to molt. Tick rearing was performed in incubator at 20 degrees C with 95% relative humidity and 12-hour light/dark photo-period regimen. We found out that adult females fed for 8 +/- 2 days and had a pre-oviposition period lasting for 7 +/- 2 days. The minimum egg incubation period was 1 month with the hatched larvae feeding for 3 +/- 1 days and molting to nymphs 3-4 months thereafter. Meanwhile, the nymphs fed for 4 +/- 1 days and molted to adult 2-3 months thereafter. For future analysis of gene expression profiles in I. persulcatus, we cloned and sequenced the actin gene (a housekeeping gene), and found that it is 92.7% to 98.6% homologous to the published sequences of related ixodid ticks. This laboratory colony of I. persulcatus will facilitate investigations on the role of tick-derived molecules on the transmission of I. persulcatus-borne pathogens and will be important for identification of potential anti-tick vaccine and acaricide target molecules.
全沟硬蜱（Ixodes persulcatus Schulze，简称全沟硬蜱）分布于俄罗斯及包括日本在内的远东地区，是多种人类病原体的传播媒介。特别是在日本，全沟硬蜱是人类莱姆病的唯一蜱虫传播媒介。为阐明全沟硬蜱传播病原体的机制，我们建立了全沟硬蜱实验室种群。用叙利亚仓鼠喂养蜱虫，收集从动物身上掉落的饱血蜱虫并饲养使其蜕皮。蜱虫饲养在20摄氏度、相对湿度95%、光照/黑暗周期为12小时的培养箱中进行。我们发现成年雌性蜱虫进食8±2天，产卵前期持续7±2天。最短卵孵化期为1个月，孵化出的幼虫进食3±1天，此后3 - 4个月蜕皮为若虫。同时，若虫进食4±1天，此后2 - 3个月蜕皮为成虫。为了未来对全沟硬蜱基因表达谱进行分析，我们克隆并测序了肌动蛋白基因（一种管家基因），发现它与已发表的相关硬蜱序列同源性为92.7%至98.6%。这个全沟硬蜱实验室种群将有助于研究蜱源分子在全沟硬蜱传播病原体中的作用，对于鉴定潜在的抗蜱疫苗和杀螨剂靶标分子具有重要意义。
