Abstract Detail

Genetics Section

Mueller, Kai [1], Wicke, Susann [1].

Evolutionary patterns of nucleotide substitutions and microstructural changes in non-coding DNA of angiosperm plastid genomes with an emphasis on extremophytes.

Plastid coding and non-coding regions have received considerable attention as tools for phylogenetic studies during the past 20 years. While several of such studies made use of large datasets comprising nearly all plastid protein-coding and rRNA genes, concatenating plastome-wide non-coding DNA (ncDNA) sequences is rarely considered for phylogenetic inferences above the genus level, even though introns and slowly evolving intergenic spacers would add valuable data. One reason for this is the difficult homology assessment of ncDNA regions across greater evolutionary distances. However, in close proximity to genic regions, ncDNA evolution is still subject to some constraints due to the presence of gene regulatory sequences. Previous studies of plastid DNA in extremophytes (e.g., parasitic plants, carnivorous plants) indicate that evolutionary rates of ncDNA correlate to some degree with the proximity to indispensable genic regions. Understanding the extent to which genes and/or their regulators affect ncDNA mutation rates may help exploiting these data to resolve notoriously recalcitrant nodes, like those exhibiting particularly high lineage diversification rates. Here, we present the results of a comprehensive analysis of the evolution of nucleotide substitution rates and microstructural changes of all plastid ncDNA regions across angiosperms. Employing a sliding window approach, we investigate locus-specific hotspots of mutations and evaluate patterns of elevation for substitutional and indel event rates within and across lineages. In turn, knowledge of these patterns will add to the empirical foundation on which improvement of alignment algorithms and statistical methods for incorporating indel information into phylogeny estimation from plastid DNA can build.

Broader Impacts:

1 - Institute for Evolution and Biodiversity, University of Muenster, Huefferstr. 1, Muenster, 48149, Germany

Keywords:
non-coding DNA
indels
substitution rates
Angiosperms
chloroplast genome
genome evolution
extremophytes.

Presentation Type: Oral Paper:Papers for Sections
Session: 6
Location: Marlborough B/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 11:00 AM
Number: 6009
Abstract ID:130
Candidate for Awards:Margaret Menzel Award