The role of exoskeleton in insect defense

外骨骼在昆虫防御中的作用

• 批准号: 06454023
• 负责人: ASHIDA Masaaki
• 金额: $ 4.54万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06454023/
• 关键词: prophenol oxidase; cuticle; protease; cascade; insect; sclerotization; lipopolysacharid; exoskeleton; フェノールオキシダーゼ; 生体防御; メラニゼーション; ドーパ; フェノール酸化酵素; 血液; 表皮; 抗菌ペプチド; ペプチドグリカン

Insect exoskeleton has often been considered to be a barrier physically protecting internal tissues from the aggression of microbes and parasitoids and from mechanical injury. We previously demonstrated that insect exoskeleton (integument, including cuticle and epidermal cells) engaged in defense not only by physical means but also by ective synthesis of antibacterial peptide under stress conditions such as infection of microbes at injured site (Proc.Natl.Acad.Sci.U.S.A.90,6275-6279(1993)). The observation changed our classical view on the function of integument in insect defense. In the present project we further investigated the active engagement of the insect integument in insect defense. The major results are as follows : a) Prophenol oxidase cascade similar to that in hemolymph is present in body wall cuticle and tracheal cuticle. ; b) Cuticular prophenol oxidase is synthesized in hemocytes and transported to cuticle, where it is localized in a specific orderly arrayd pattern. c) Cuticular prophenol oxidase had retention time different from that of hemolymph on reversed phase ODS column chromatography, indicating that prophenol oxidase in hemolymph is modified in the process of its transport from hemolymph to cuticle. We are currently investigating the structural difference between prophenol oxidases from hemolymph and from cuticle. d) Prophenol oxidase a activating enzyme was purified from cuticles and its primary structure was deduced from base sequence of prophenol oxidase activating enzyme cDNA.e) Cecropin synthesis is induced in epidermal cells after abrasion of body wall cuticle and the application of lipopolysaccharide at the abraded part. Very small amount of lipopolysaccharide (a few picogram) could induce the synthesis when it was applied at abraded cuticle of 5th instar silkworm.

昆虫外骨骼通常被认为是保护内部组织免受微生物和寄生虫侵袭以及机械损伤的物理屏障。我们以前证明，昆虫外骨骼（被膜，包括角质层和表皮细胞）不仅通过物理手段，而且通过在应激条件下如在损伤部位感染微生物有效合成抗菌肽来参与防御（Proc.Natl.Acad.Sci.U.S.A.90，6275 -6279（1993））。这一发现改变了我们对昆虫体壁防御功能的传统看法。在本项目中，我们进一步研究了昆虫体壁在昆虫防御中的积极参与。主要结果如下：（1）在体壁角质层和气管角质层中存在与血淋巴相似的酚氧化酶级联反应。B）表皮酚氧化酶在血细胞中合成并运输到表皮，在那里它以特定的有序排列模式定位。（3）在反相ODS柱层析上，表皮和血淋巴中的原酚氧化酶的保留时间不同，说明血淋巴中的原酚氧化酶在从血淋巴向表皮转运的过程中发生了修饰。我们目前正在研究血淋巴和角质层中酚氧化酶原的结构差异。d）从角质层中纯化了一种激活酶-将极少量的脂多糖（几皮克）涂抹在5龄蚕的擦伤表皮上，即可诱导其合成。

项目成果

Brey, P.T.: "Tyrosinase-type prophenoloxidase distribution in the alimentary canal of strains of Anopheles gambiae refractory and susceptible to Plasmodium infection." Experimental Parasitol. 80. 654-664 (1995)

Brey, P.T.：“酪氨酸酶型酚氧化酶原在难治且易受疟原虫感染的冈比亚按蚊菌株的消化道中分布。”

Yasuhara, Y.: "Re-examination of properties of prophenoloxidase isolated from larval hemolymph of the silkworm, Bombyx mori." Arch.Biochem.Biophys.320. 14-23 (1995)

Yasuhara, Y.：“重新检查从家蚕幼虫血淋巴中分离出的酚氧化酶原的特性。”

Yoshida, H.: "Purification of a peptidoglycan recognition protein from hemolymph of the silkworm, Bombyx mori" J.Biol.Chem.271. 13854-13860 (1996)

Yoshida, H.：“从家蚕血淋巴中纯化肽聚糖识别蛋白”J.Biol.Chem.271。

Brey,P.T.: "Tyrosinase-type prophenoloxidase distribution in the alimentary canal of strains of Anopheles gambiae refractory and susceptible to Plasmodium infection" Experimental Parasitol. 80. 654-664 (1995)

Brey，P.T.：“酪氨酸酶型酚氧化酶原在难治且易受疟原虫感染的冈比亚按蚊菌株消化道中的分布”实验性寄生虫醇。

Ashida,M.: "Role of the integument in insect defense : Prophenoloxidase cascade in the cuticular matrix" Proc.Natl.Acad.Sci.U.S.A.92. 10698-10702 (1995)

Ashida,M.：“体被在昆虫防御中的作用：角质层基质中的酚氧化酶级联”Proc.Natl.Acad.Sci.U.S.A.92。