Message - 7th IAL Symposium

The 7 th International Association for Lichenology Symposium 2012
NOVEL MOLECULAR MARKERS AND THEIR UTILITY IN MOLECULAR
SYSTEMATICS OF FUNGI
Miadlikowska J. M. 1
1 Duke University, Department of Biology, Durham, North Carolina, United States
Although next generation sequencing methods have proven to be very successful in accelerating the
process of data acquisition, development of novel molecular markers remains an integral component
of the scalability of molecular systematic studies on lichen-forming fungi and associated symbionts.
Existing fungal phylogenies from large-scale to species level surveys demonstrate an urgent need for
novel single-copy protein-coding genes to resolve with high confidence phylogenetic relationships. For
example, when using a cumulative super-matrix approach with available sequences of five frequently
targeted loci for Lecanoromycetes, the resulting multilocus phylogeny was resolved but with many
portions of the tree inconclusively supported, especially at deeper nodes. As part of the Assembling
the Fungal Tree of Life project (AFToL 2), a comparative genomic approach was adopted to select all
genes with the greatest potential to resolve the most challenging nodes of the fungal tree of life and to
test their performance phylogenetically. Based on the comparison of 39 fungal genomes, 71 potentially
single-copy genes were selected and a total of 243 primer pairs were designed and tested with six
exemplar species representing Ascomycota, Basidiomycota and early-diverging fungi. The successful
amplification and sequencing of 19 gene regions across these 6 representative taxa adds a total of
about 15,000 bp per taxon, to the commonly sequenced nucLSU, nucSSU, mitSSU, MCM7, RPB1 and
RPB2. The data set we generated for AFToL 2 includes 37 non-lichenized fungi for which the genomes
are available and up to 26 lichen-forming members of the Lecanoromycetes, Dothideomycetes,
Eurothiomycetes and Arthoniomycetes, for which the sequences were obtained from cultures of the
mycobionts. Phylogenetic analyses were completed on each of the 19 novel and 8 commonly used
gene regions and their multilocus combinations on the same set of taxa (including representatives of
lichen-forming fungi) when possible. Phylogenetic efficiency (e.g., the level of resolution and internode
robustness) and phylogenetic informativeness among all loci was compared and the utility of the novel
genes in molecular systematics at various taxonomic levels is discussed. Phylogenetic performance of
selected genes at the species level is shown based on a systematic revision of the genus Peltigera.
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