Clark M A, Baumann L, Baumann P
Microbiology Section, University of California, Davis, CA 95616-8665, USA.
Curr Microbiol. 1998 Mar;36(3):158-63. doi: 10.1007/pl00006760.
Buchnera aphidicola is a prokaryotic endosymbiont of the aphid Schizaphis graminum. From past and present nucleotide sequence analyses of the B. aphidicola genome, we have assembled a 34. 7-kilobase (kb) DNA segment. This segment contains genes coding for 32 open reading frames (ORFs), which corresponded to 89.9% of the DNA. All of these ORFs could be identified with homologous regions of the Escherichia coli genome. The order of the genes with established functions was groELS-trmE-rnpA-rpmH-dnaA-dnaN-gyrB-atpCDGAH FEB-gidA-fdx-hscA- hscB-nifS-ilvDC-rep-trxA-rho. The order of genes in small DNA fragments was conserved in both B. aphidicola and E. coli. Most of these fragments were in approximately the same region of the E. coli genome. The latter organism, however, contained many additional inserted genes within and between the fragments. The results of the B. aphidicola genome analyses indicate that the endosymbiont has many properties of free-living bacteria.
蚜虫内共生菌是麦二叉蚜的一种原核内共生体。通过对蚜虫内共生菌基因组过去和现在的核苷酸序列分析，我们组装了一个34.7千碱基（kb）的DNA片段。该片段包含编码32个开放阅读框（ORF）的基因，这些基因占DNA的89.9%。所有这些开放阅读框都可以通过与大肠杆菌基因组的同源区域来鉴定。具有已知功能的基因顺序为groELS-trmE-rnpA-rpmH-dnaA-dnaN-gyrB-atpCDGAH FEB-gidA-fdx-hscA- hscB-nifS-ilvDC-rep-trxA-rho。小DNA片段中的基因顺序在蚜虫内共生菌和大肠杆菌中都是保守的。这些片段中的大多数在大肠杆菌基因组的大致相同区域。然而，后一种生物在片段内部和片段之间包含许多额外插入的基因。蚜虫内共生菌基因组分析结果表明，这种内共生体具有许多自由生活细菌的特性。
