The RDP (Ribosomal Database Project) continues

The Ribosomal Database Project (RDP-II), previously described by Maidak et al,, continued during the past year to add new rRNA sequences to the aligne d data and to improve the analysis commands. Release 7.1 (September 17, 199 9) included more than 10 700 small subunit rRNa sequences. More than 850 ty pe strain sequences were identified and added to the prokaryotic alignment, bringing the total number of type sequences to 3324 representing 2460 diff erent species. Availability of an RDP-II mirror site in Japan is also near completion. RDP-II provides aligned and annotated rRNA sequences, derived p hylogenetic trees and taxonomic hierarchies, and analysis services through its WWW server (http://rdp.cme.msu.edu/). Analysis services include rRNA pr obe checking, approximate phylogenetic placement of user sequences, screeni ng user sequences for possible chimeric rRMA sequences, automated alignment , production of similarity matrices and services to plan and analyze termin al restriction fragment length polymorphism (T-RFLP) experiments.