Systematics Section / ASPT
Bain, John F , Jansen, Robert K. .
A cpDNA hairpin structure provides useful phylogenetic data within tribe Senecioneae (Asteraceae).
Hairpin (stem-loop) regions of cpDNA are thought to act as mutational hotspots within the chloroplast genome and changes within these regions are often ignored in phylogenetic analyses because of their lack of stability. We describe inversions associated with a stem-loop region within the psbA-trnH spacer region of cpDNA that appear to be phylogenetically useful within the Asteraceae, especially in the tribe Senecioneae. The stem-loop region is characterized by two loops found at the top of a 15 bp stem, with each separated by a second 7 or 8 bp stem. Within the Asteraceae, inversions have occurred at the base of each loop region resulting in a total of 4 different "inversion haplotypes", one of which characterizes the Gnaphalieae. The pattern of inversion haplotype distribution within the tribe Senecioneae supports the notion that subtribe Tussilagininae is paraphyletic, subtribe Senecioninae is monophyletic and that Blennosperma is not basal within the tribe. Within the subtribe Tussilagininae one inversion haplotype shows homoplasy but in all other instances the presence of point mutations within the stem-loop region allow different inversion events involving the same region to be distinguished.
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1 - University of Lethbridge, Biological Sciences, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada
2 - University of Texas Austin, Section of Integrative Biology, 1 University Station, A6700, Austin, Texas, 78712-7640, USA
Presentation Type: Poster
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM