Previous Article | Next Article ![]()
Appl. Environ. Microbiol., Dec 1997, 4645-4650, Vol 63, No. 12
GC Wang and Y Wang
PCR is routinely used in amplification and cloning of rRNA genes from
environmental DNA samples for studies of microbial community structure and
identification of novel organisms. There have been concerns about
generation of chimeric sequences as a consequence of PCR coamplification of
highly conserved genes, because such sequences may lead to reports of
nonexistent organisms. To quantify the frequency of chimeric molecule
formation, mixed genomic DNAs from eight actinomycete species whose 16S
rRNA sequences had been determined were used for PCR coamplification of 16S
rRNA genes. A large number of cloned 16S ribosomal DNAs were examined by
sequence analysis, and chimeric molecules were identified by
multiple-sequence alignment with reference species. Here, we report that
the level of occurrence of chimeric sequences after 30 cycles of PCR
amplification was 32%. We also show that PCR-induced chimeras were formed
between different rRNA gene copies from the same organism. Because of the
wide use of PCR for direct isolation of 16S rRNA sequences from
environmental DNA to assess microbial diversity, the extent of chimeric
molecule formation deserves serious attention.
Copyright © 1997, American Society for Microbiology
Frequency of formation of chimeric molecules as a consequence of PCR coamplification of 16S rRNA genes from mixed bacterial genomes
Institute of Molecular and Cell Biology, National University of Singapore, Singapore.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|