PMC:1069646 / 44965-47240 JSONTXT

{"project":"2_test","denotations":[{"id":"15780005-15024419-84825103","span":{"begin":461,"end":464},"obj":"15024419"},{"id":"15780005-15111095-84825104","span":{"begin":465,"end":468},"obj":"15111095"},{"id":"15780005-11812492-84825105","span":{"begin":469,"end":472},"obj":"11812492"},{"id":"15780005-12089438-84825106","span":{"begin":1145,"end":1148},"obj":"12089438"},{"id":"15780005-12177348-84825107","span":{"begin":1153,"end":1156},"obj":"12177348"},{"id":"15780005-9823893-84825108","span":{"begin":1157,"end":1160},"obj":"9823893"},{"id":"15780005-9717214-84825109","span":{"begin":1165,"end":1168},"obj":"9717214"},{"id":"15780005-12219091-84825110","span":{"begin":1302,"end":1305},"obj":"12219091"},{"id":"15780005-12177348-84825111","span":{"begin":1310,"end":1313},"obj":"12177348"},{"id":"15780005-12522265-84825112","span":{"begin":1476,"end":1479},"obj":"12522265"},{"id":"15780005-15024419-84825113","span":{"begin":1526,"end":1529},"obj":"15024419"},{"id":"15780005-12219091-84825114","span":{"begin":1530,"end":1533},"obj":"12219091"},{"id":"T11433","span":{"begin":461,"end":464},"obj":"15024419"},{"id":"T79888","span":{"begin":465,"end":468},"obj":"15111095"},{"id":"T31766","span":{"begin":469,"end":472},"obj":"11812492"},{"id":"T80220","span":{"begin":1145,"end":1148},"obj":"12089438"},{"id":"T64804","span":{"begin":1153,"end":1156},"obj":"12177348"},{"id":"T91047","span":{"begin":1157,"end":1160},"obj":"9823893"},{"id":"T37642","span":{"begin":1165,"end":1168},"obj":"9717214"},{"id":"T2599","span":{"begin":1302,"end":1305},"obj":"12219091"},{"id":"T28578","span":{"begin":1310,"end":1313},"obj":"12177348"},{"id":"T66091","span":{"begin":1476,"end":1479},"obj":"12522265"},{"id":"T48553","span":{"begin":1526,"end":1529},"obj":"15024419"},{"id":"T76683","span":{"begin":1530,"end":1533},"obj":"12219091"}],"text":"Conclusions\nComparing the genomes of wBm and Rickettsia to those of gamma-proteobacterial symbionts points to general similarities and distinctions in the evolution of endosymbionts. The genomes of R. conorii and Wolbachia species contain numerous repeats of various classes that are much more abundant than in the gamma-proteobacterial endosymbionts (Table 1). This correlates with the minimal gene colinearity between the genomes of Wolbachia and Rickettsia [103,114,163] (Figure 5). By contrast, gamma-proteobacterial endosymbionts share a variety of operons with one another, and even with free-living relatives, despite the dramatic gene loss. Furthermore, gamma-proteobacterial endosymbionts (with the exception of Wigglesworthia) have lost crucial genes involved in recombinational repair, whereas almost no gene loss in this functional class was observed in Wolbachia or Rickettsia spp. Active recombination between repeats might have led to both gene loss and genome shuffling in Wolbachia and Rickettsia spp., whereas other mechanisms of genome reduction were probably involved in the evolution of gamma-proteobacterial endosymbionts [109,120,121,122,123,164]\nComparative genome analysis highlights the different metabolic capabilities that render endosymbionts indispensable to their hosts [108,119,121]. For example, Buchnera and Blochmannia retain a nearly complete repertoire of amino acid biosynthesis pathways and supply amino acids to their insect hosts [110,112]. In contrast, wBm, wMel, and Wigglesworthia [103,108] have lost nearly all of these pathways but retain the pathways for the biosynthesis of nucleotides and some coenzymes (Table 3). Thus, endosymbiotic organisms in different divisions of proteobacteria independently evolved distinct strategies for symbiont–host interactions.\nGenomic analysis of the alpha-proteobacterium wBm, the first sequenced endosymbiont from a human parasitic nematode, provides new insights into the evolution of intracellular bacterial symbiosis and clues to the role of Wolbachia in the mutualistic relationship with the nematode. It is anticipated that continued genome analysis of nematodes and their endosymbionts will provide novel targets for antimicrobials aimed at the elimination of human filarial parasites."}