Studies on the Dual Functions of Defense Molecules

麻蝇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，以响应身体损伤。这种凝集素对于从以下证据中消除外来物质是必不可少的。将绵羊红细胞注入肉蝇幼虫腹腔，随着时间的推移，绵羊红细胞被溶解并从血淋巴中消失。然而.当将血细胞与抗麻蝇属凝集素或半抗原-糖半乳糖的抗体一起注射时，没有检测到血细胞的消除。血清或非半抗原糖葡萄糖对血细胞的溶解没有影响。用麻蝇凝集素cDNA进行的北方印迹分析表明，在没有任何外界刺激的情况下，该凝集素基因在个体发育过程中表达两次：第一次在胚胎期，第二次在胚胎期，第三次在胚胎期，第四次在胚胎期，第四次在胚胎期，第五次在胚胎期，第六次在胚胎期，第七次在胚胎期，第七次在胚胎期，第八次在胚胎期， 关于我们 然后在蛹期再次出现。在蛹期合成的麻蝇凝集素被证明是必需的成虫盘的发展。当腿或翅盘在蜕皮激素存在下体外培养时，它们分化成成虫结构。当培养基中存在抗麻蝇凝集素或半乳糖时，分化停止在脱泡阶段，而免疫前血清或葡萄糖不干扰成虫盘的分化。这表明肉蝇凝集素对成虫盘的终末分化是必不可少的。由于培养基中没有添加麻蝇凝集素，因此它必须由成虫盘自身合成。免疫印迹实验表明，成虫盘（翼盘和腿盘）合成麻蝇凝集素在apolysis阶段。由此可见，麻蝇凝集素具有防御和发育的双重功能，一个基因一个蛋白一个功能的观点可能并不一定正确。生物系统似乎能够以两种方式（或多种方式）使用asme蛋白来维持其稳态，这取决于环境条件。少

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