Forty four accessions of wild barley, H. spontaneum were assayed to study the methylation status of ribosomal DNA repeat units. For this purpose, BamHI and HpaII, which are, methylation sensitive restriction enzymes and MspI, which is methyl insensitive enzyme, were used for restriction digestion. Southern blots were hybridized with pTa71 probe, which represented a complete ribosomal DNA repeat...

BACKGROUND Assessment of the biodiversity of communities of small organisms is most readily done using PCR-based analysis of environmental samples consisting of mixtures of individuals. Known as metagenetics, this approach has transformed understanding of microbial communities and is beginning to be applied to metazoans as well. Unlike microbial studies, where analysis of the 16S ribosomal DNA ...

Ribosomal DNA (rDNA) sequence data were compared for five species of Globodera, including G. rostochiensis, G. pallida, G. virginiae, and two undescribed Globodera isolates from Mexico collected from weed species and maintained on Solanum dulcamara. The rDNA comparisons included both internal transcribed spacers (ITS1 and ITS2), the 5.8S rRNA gene, and small portions of the 3' end of the 18S ge...

Previous reports that radioactivity was bound to rat liver DNA in vivo after administration of 2-acetylaminofluorene (AAF)-9-14C were confirmed. In addition, administration of several other AAF derivatives, namely N-hydroxy-AAF-9 -14C, N-acetoxy-AAF-914C, and the glucuronide of N-hydroxyAAF-9)4C, led to the binding of higher levels of radioactivity to rat liver ribosomal RNA and DNA. Maximum le...

All of the marine bacterioplankton-derived 16S ribosomal DNA sequences previously deposited in GenBank were reanalyzed to determine the number of bacterial species in the oceanic surface waters. These sequences have been entered into the database since 1990. The rate of new additions reached a peak in 1999 and subsequently leveled off, suggesting that much of the marine microbial species richne...