Gil Rosario, Silva Francisco J, Zientz Evelyn, Delmotte François, González-Candelas Fernando, Latorre Amparo, Rausell Carolina, Kamerbeek Judith, Gadau Jürgen, Hölldobler Bert, van Ham Roeland C H J, Gross Roy, Moya Andrés
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Apartat Oficial 2085, 46071 Valencia, Spain.
Proc Natl Acad Sci U S A. 2003 Aug 5;100(16):9388-93. doi: 10.1073/pnas.1533499100. Epub 2003 Jul 28.
Bacterial symbioses are widespread among insects, probably being one of the key factors of their evolutionary success. We present the complete genome sequence of Blochmannia floridanus, the primary endosymbiont of carpenter ants. Although these ants feed on a complex diet, this symbiosis very likely has a nutritional basis: Blochmannia is able to supply nitrogen and sulfur compounds to the host while it takes advantage of the host metabolic machinery. Remarkably, these bacteria lack all known genes involved in replication initiation (dnaA, priA, and recA). The phylogenetic analysis of a set of conserved protein-coding genes shows that Bl. floridanus is phylogenetically related to Buchnera aphidicola and Wigglesworthia glossinidia, the other endosymbiotic bacteria whose complete genomes have been sequenced so far. Comparative analysis of the five known genomes from insect endosymbiotic bacteria reveals they share only 313 genes, a number that may be close to the minimum gene set necessary to sustain endosymbiotic life.
细菌共生现象在昆虫中广泛存在，这可能是它们进化成功的关键因素之一。我们展示了佛罗里达布洛赫曼氏菌（Blochmannia floridanus）的完整基因组序列，它是木匠蚁的主要内共生菌。尽管这些蚂蚁的食物种类复杂，但这种共生关系很可能有营养基础：布洛赫曼氏菌能够为宿主提供氮和硫化合物，同时利用宿主的代谢机制。值得注意的是，这些细菌缺乏所有已知的参与复制起始的基因（dnaA、priA和recA）。对一组保守蛋白质编码基因的系统发育分析表明，佛罗里达布洛赫曼氏菌在系统发育上与蚜虫内共生菌（Buchnera aphidicola）和舌蝇内共生菌（Wigglesworthia glossinidia）相关，这是另外两种其完整基因组已被测序的内共生细菌。对来自昆虫内共生细菌的五个已知基因组的比较分析表明，它们仅共享313个基因，这个数量可能接近维持内共生生活所需的最小基因集。
