2014 Annual Science Report
University of Illinois at Urbana-Champaign Reporting | SEP 2013 – DEC 2014
Project 12 Enrichment of Eukaryotic DNA
This projects seeks to understand the early evolution of eukaryotic cells by comparing the genomes of diverse eukaryotic microbes and asking what genes are shared and when features of the eukaryotic cell evolved.
The immense diversity of microbial eukaryotes is not reflected in current or completed genome projects. Sequencing efforts have focused overwhelmingly (over 86%) on either opisthokont (animal and fungi) and plant lineages, or secondarily-reduced parasitic protists. Few genomes of free-living microbial eukaryotes are sequenced, despite their critical importance in ecology, evolution, and basic cellular biology. By comparing the genomes of these new protists with known organisms, we will gain insight into the diversity and complexity of the eukaryotic cell. We can also infer key evolutionary events in the history of the eukaryotes.
As with most bacteria, most free-living protistan taxa are difficult to obtain in pure culture, and are deposited in culture collections as mixed consortia with bacteria. To aid in study of early eukaryotic evolution, we are have cultured about 120 novel amoeba isolates from from marine and freshwater environments. Many of the newly classified isolates (6/33) represent novel groups of eukaryotes. These amoebae range in size from about 3 μM to over 100 μM and have diverse types of motility. Thirty-three have been sequenced and classified using ssu rRNA. None of the isolates have close relatives with sequenced genomes.