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Studies on the Dual Functions of Defense Molecules

防御分子双重功能的研究

基本信息

批准号：
63440080
负责人：
NATORI Shunji
金额：
$ 19.33万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

Sarcophaga lectin is a galactose-binding lectin induced in the hemolymph of Sarcophaga peregrina (flesh fly) larvae in response to body injury. This lectin is essential for the elimination of foreign substance from the following evidence. When sheep red blood cells were injected into the abdominal cavity of Sarcophaga larvae, they were lysed and disappeared from the hemolymph withtime. However. when the blood cells were injected together with antibody against Sarcophaga lectin or hapten-sugar galactose, no elimination of the blood cells was detected. Premimune serum or non-hapten sugar glucose had no effect on the lysis of the blood cells. This indicates that Sarcophaga lectin is a defense molecule and participates in the elimination of foreign of substances invading through the damaged body wall.Northern blot analysis using cDNA for Sarcophaga lectin revealed that the gene for this lectin is expressed twice during ontogeny without any outside stimuli : First in the embryonic stage and … More then again in the pupal stage. Sarcophaga lectin synthesized at the pupal stage was shown to be necessary for the development of imaginal discs. When leg or wing discs were cultured in vitro in the presence of ecdysone, they differentiate into adult structures. When anti-Sarcophaga lectin or galactose was present in the culture medium, the differentiation stopped at the stage of apolysis, whereas preimmune serum or glucose did not interfere with the differentiation of imaginal discs. This indicates that Sarcophaga lectin is essential for the terminal differentiation of imaginal discs. Since no Sarcophaga lectin was added to the culture medium, it must be synthesized by the imaginal disc itself. Immunoblotting experiments showed that imaginal discs (both wing and leg discs) synthesize Sarcophaga lectin at the stage of apolysis. Therefor, it is clear that Sarcophaga lectin has dual functions in defense and development.It is likely that the concept of one gene-one protein-one function is not necessarily correct. Biological system seems to be able to use the asme protein in two ways (or in multiple ways) to maintain its homeostasis, depending upon environmental conditions. Less

Sarcophaga 凝集素是一种半乳糖结合凝集素，在肉蝇幼虫的血淋巴中诱导产生，以响应身体损伤。从以下证据来看，这种凝集素对于消除异物至关重要。当绵羊红细胞被注射到石噬菌幼虫的腹腔中时，随着时间的推移，它们被裂解并从血淋巴中消失。然而。当将血细胞与抗Sarcophaga凝集素或半抗原-半乳糖的抗体一起注射时，没有检测到血细胞的消除。预免疫血清或非半抗原葡萄糖对血细胞的裂解没有影响。这表明Sarcophaga凝集素是一种防御分子，参与消除通过受损体壁侵入的外来物质。使用Sarcophaga凝集素的cDNA进行的Northern印迹分析表明，这种凝集素的基因在没有任何外界刺激的个体发育过程中表达两次：首先在胚胎阶段，然后在蛹阶段再次表达。蛹期合成的石食凝集素被证明对于成虫盘的发育是必需的。当腿或翼盘在蜕皮激素存在的情况下进行体外培养时，它们会分化为成体结构。当培养基中存在抗石噬菌凝集素或半乳糖时，分化在解胞阶段停止，而免疫前血清或葡萄糖不干扰成虫盘的分化。这表明石噬菌凝集素对于成虫盘的终末分化至关重要。由于培养基中没有添加石噬菌凝集素，因此它必须由成虫盘本身合成。免疫印迹实验表明，成虫盘（翼盘和腿盘）在解体阶段合成石噬菌凝集素。因此，很明显，Sarcophaga凝集素在防御和发育方面具有双重功能。“一种基因-一种蛋白质-一种功能”的概念很可能并不一定正确。生物系统似乎能够根据环境条件以两种方式（或多种方式）使用 asme 蛋白来维持其体内平衡。较少的