Showing papers by "Elizabeth A. Zimmer published in 1996"
TL;DR: The Himalayas and central and western China are the current centers of diversity of the ginseng genus and the low ITS sequence divergence and a close relationship among species in that region suggest that rapid evolutionary radiation may have created such a diversity of Panax in the Himalaya and in central and eastern China.
444 citations
TL;DR: A general model of angiosperm ITS2 secondary structure that shows common pairing relationships for most of the conserved sequence tracts is proposed and variations in secondary structure predictions for sequences from different taxa indicate that compensatory mutation is not limited to paired positions.
Abstract: The two internal transcribed spacers (ITS1 and ITS2) of nuclear ribosomal DNA have become commonly exploited sources of informative variation for interspecific-/intergeneric-level phylogenetic analyses among angiosperms and other eukaryotes. We present an alignment in which one-third to one-half of the ITS2 sequence is alignable above the family level in angiosperms and a phenetic analysis showing that ITS2 contains information sufficient to diagnose lineages at several hierarchical levels. Base compositional analysis shows that angiosperm ITS2 is inherently GC-rich, and that the proportion of T is much more variable than that for other bases. We propose a general model of angiosperm ITS2 secondary structure that shows common pairing relationships for most of the conserved sequence tracts. Variations in our secondary structure predictions for sequences from different taxa indicate that compensatory mutation is not limited to paired positions.
164 citations