In:
Journal of Bacteriology, American Society for Microbiology, Vol. 180, No. 19 ( 1998-10), p. 5003-5009
Kurzfassung:
Molecular phylogenetic surveys have recently revealed an ecologically widespread crenarchaeal group that inhabits cold and temperate terrestrial and marine environments. To date these organisms have resisted isolation in pure culture, and so their phenotypic and genotypic characteristics remain largely unknown. To characterize these archaea, and to extend methodological approaches for characterizing uncultivated microorganisms, we initiated genomic analyses of the nonthermophilic crenarchaeote Cenarchaeum symbiosum found living in association with a marine sponge, Axinella mexicana . Complex DNA libraries derived from the host-symbiont population yielded several large clones containing the ribosomal operon from C. symbiosum . Unexpectedly, cloning and sequence analysis revealed the presence of two closely related variants that were consistently found in the majority of host individuals analyzed. Homologous regions from the two variants were sequenced and compared in detail. The variants exhibit 〉 99.2% sequence identity in both small- and large-subunit rRNA genes and they contain homologous protein-encoding genes in identical order and orientation over a 28-kbp overlapping region. Our study not only indicates the potential for characterizing uncultivated prokaryotes by genome sequencing but also identifies the primary complication inherent in the approach: the widespread genomic microheterogeneity in naturally occurring prokaryotic populations.
Materialart:
Online-Ressource
ISSN:
0021-9193
,
1098-5530
DOI:
10.1128/JB.180.19.5003-5009.1998
Sprache:
Englisch
Verlag:
American Society for Microbiology
Publikationsdatum:
1998
ZDB Id:
1481988-0
SSG:
12
