Molecular characterization of Rhipicephalus (Boophilus) microplus Bm86 homologue from Haemaphysalis longicornis ticks
Molecular characterization of Rhipicephalus (Boophilus) microplus Bm86 homologue from Haemaphysalis longicornis ticks
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DOI：
10.1016/j.vetpar.2007.01.015
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发表时间：
2007-05-15
影响因子：
2.6
通讯作者：
Fujisaki, Kozo
中科院分区：
文献类型：
--
作者：
Liao, Min;Zhou, Jinlin;Fujisaki, Kozo
从半饱血的雌性长角血蜱制备的中肠cDNA文库的EST数据库中的一个序列已被发现是微小扇头蜱（牛蜱）蜱的Bm 86基因的同源物。获得了含有1785开放阅读片段（ORF）的全长序列，并将其命名为H186基因。预测的H186基因的氨基酸序列显示与Bm 86基因37%的同一性。H186是一种GPI锚定的膜结合糖蛋白，具有19个氨基酸的信号序列和邻近羧基末端的22个氨基酸的疏水区。H186与Bm 86共同的最重要特征是6个半胱氨酸残基的重复模式，形成表皮生长因子（EGF）样结构域。RT-PCR分析表明，H186 mRNA转录本在H. longicornis中表达，在成蜱的中肠中也有表达。H186在大肠杆菌中表达为基因10融合蛋白。小鼠抗重组H186血清在Western印迹分析中识别半饱血蜱的中肠裂解物中的86 kDa蛋白条带，并且在间接免疫荧光抗体试验（IFAT）中显示出在中肠细胞的腔表面上的强烈反应。通过RNAi沉默H186基因导致饱食蜱体重的显著降低。这是自1989年首次报道Bm 86以来，首次报道Bm 86同源物在硬蜱和硬蜱不同属种中的克隆和鉴定。(c)2007 Elsevier B. V.保留所有权利。
One sequence in the EST database of a midgut cDNA library prepared from semi-engorged female Haemaphysalis longicornis ticks has been found to be a homologue of the Bm86 gene of Rhipicephalus (Boophilus) microplus ticks. The full-length sequence containing a 1785 by open reading fragment (ORF) was obtained and designated as the Hl86 gene. The predicted amino acid sequence of the Hl86 gene shows a 37% identity to the Bm86 gene. Hl86 is predicted to be a GPI-anchored membrane-bound glycoprotein with a 19-amino acid signal sequence and a 22-amino acid hydrophobic region adjacent to the carboxyl terminus. The most important feature that Hl86 has in common with Bm86 is the repeated pattern of 6 cysteine residues forming epidermal growth factor (EGF)-like domains. RT-PCR analysis showed that Hl86 mRNA transcripts are expressed in all the life cycles of H. longicornis, and the expression was found in the midgut of the adult tick. The Hl86 was expressed in Escherichia coli as a gene 10 fusion protein. Mouse anti-recombinant Hl86 serum recognized an 86 kDa protein band in the midgut lysate of semi-engorged ticks in Western blot analysis and showed a strong reaction on the luminal surface of midgut cells in an indirect immunofluorescent antibody test (IFAT). Silencing of the Hl86 gene by RNAi led to a significant reduction in the engorged tick body weight. This is the first report of cloning and characterization of the Bm86 homologue in different genera and species of ixodid and argasid ticks since Bm86 was first reported in 1989. (c) 2007 Elsevier B.V. All rights reserved.