Komaki K, Ishikawa H
Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan.
Insect Biochem Mol Biol. 2000 Mar;30(3):253-8. doi: 10.1016/s0965-1748(99)00125-3.
Buchnera, endosymbiotic bacteria of aphids possess many genomic copies per cell. In this study, we estimated genomic copy number per Buchnera cell from host insects at various developmental stages and of two different morphs, apterae and alatae, by fluorimetry and real-time quantitative PCR. The results indicated that the genomic copy number of Buchnera increased during postembryonic development of insects to adulthood, and that it decreased during the host's ageing. In Buchnera from alatae, the genomic copy number per cell was about twice as many as in those from apterae. DAPI-staining showed that the distribution of the genomic DNA in the Buchnera cells from old insects tended to aggregate, suggesting that intracellular structure of the genomic DNA of Buchnera varies in response to the physiological conditions of their host.
布赫纳氏菌是蚜虫的内共生细菌，每个细胞拥有多个基因组拷贝。在本研究中，我们通过荧光测定法和实时定量PCR，估计了处于不同发育阶段以及两种不同形态（无翅型和有翅型）的宿主昆虫中每个布赫纳氏菌细胞的基因组拷贝数。结果表明，布赫纳氏菌的基因组拷贝数在昆虫胚胎后发育至成年期的过程中增加，而在宿主衰老过程中减少。在有翅型蚜虫的布赫纳氏菌中，每个细胞的基因组拷贝数约为无翅型蚜虫中布赫纳氏菌的两倍。DAPI染色显示，老龄昆虫的布赫纳氏菌细胞中基因组DNA的分布趋于聚集，这表明布赫纳氏菌基因组DNA的细胞内结构会根据宿主的生理状况而变化。
