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Evolution of Homopterae and Their intracellular Symblonts

同翅目及其细胞内符号的进化

基本信息

批准号：
06044065
负责人：
ISHIKAWA Hajime
金额：
$ 2.82万
依托单位：
University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

1. This International Scientific Research Program enabled us to work on the ecology of social aphids in detail. We investigated the life cycle of The cabius populimonilis in Colorada and Arizona, U.S.A.In Arizona their life cycle was not associated with migration while in Colorado the life cycle was divided into two, migratory and non-migratory. Analyzes of the individuals in the gall suggested that non-migratory life cycle has evolved secondarily from the migratory one through viviposition by alatae within the gall and apterization of alatae in support of the GP hypothesis by Aoki and Kurosu (1986).2. Except a few specified groups, all the aphid species harbor prokaryotic symbiont in the bacteriocyte. The previous studies demonstrated that aphid, unlike many other insects, does not convert the nitrogen wastes into uric acid, but produces Gln and Asn from the wastes. The amino acids are metabolized by the symbionts to produce essential amino acids for the host. In the present study, we … More demonstrated that planthopper recycles organic nitrogeous compounds in a different manner exploiting its yeastlike symbiont. Planthopper produces uric acid from the wastes and stores it in the tissue, which symbiont metabolizes to produce nitrogenous compounds usable to the host.3. Aphid symbiont, closely related to E.coli, belongs to the gamma3 subdivision of Proteobacteria. It synthesizes selectively a large amount of symbionin, a stress protein homologous to E.Coli GroEL,which functions as molecular chaperone. In the present study, nucleotide sequences encoding symbionins from three closely interrelated aphids were compared with one another and that for GroEL.It was suggested that in these proteins a particular position is highly susceptible to amino acid substitution, through which symbionins, the GroEL homologs symbionts seemed to have acquired a unique function as phosphotransferase on top of the activity as molecular chaperone. This may represent a rare example of non-neutral evolution of molecule under the positive selection pressure. Less

1. 这项国际科学研究计划使我们能够详细研究社会蚜虫的生态学。我们调查了美国科罗拉多州和亚利桑那州的黑豆的生命周期。在亚利桑那州，它们的生命周期与迁徙无关，而在科罗拉多州，生命周期分为两种，即迁徙和非迁徙。对瘿中个体的分析表明，非迁徙生命周期是通过瘿内翼状体的胎生和翼状体的进化而从迁徙性生命周期进化而来的，这支持了Aoki和Kurosu (1986)的GP假说。2．除少数特定类群外，所有蚜虫的细菌细胞中都存在原核共生体。先前的研究表明，与许多其他昆虫不同，蚜虫不会将氮废物转化为尿酸，而是从废物中产生谷氨酰胺和天冬氨酸。氨基酸由共生体代谢，产生宿主必需的氨基酸。在本研究中，我们证明飞虱利用其酵母共生体以不同的方式回收有机含氮化合物。飞虱从废物中产生尿酸并将其储存在组织中，其共生代谢产生宿主可用的含氮化合物。3．蚜虫共生体与大肠杆菌密切相关，属于变形菌门的 gamma3 亚门。它选择性地合成大量的共生素，这是一种与大肠杆菌GroEL同源的应激蛋白，起到分子伴侣的作用。在本研究中，将编码来自三种密切相关的蚜虫的共生素的核苷酸序列与GroEL的核苷酸序列进行了比较。结果表明，在这些蛋白质中，特定位置对氨基酸取代高度敏感，通过这种取代，共生素、GroEL同系物共生体似乎除了作为分子伴侣的活性之外还获得了作为磷酸转移酶的独特功能。这可能代表了正选择压力下分子非中性演化的罕见例子。较少的