Examining the macroevolutionary trajectories in Amoebozoa, a major lineage of eukaryotes

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Our current view of the eukaryotic Tree of Life suggests that life can be divided up into several major groups, including the Amoebozoa, the branch closest to our own major group, the Obazoa. The Amoebozoa is composed primarily of organisms that have single, amoeboid cells as part of their life cycles. Such cells are dynamic, changing shape as they move with transient extensions of the cell called pseudopodia. These cells are also used for engulfing prey. Amoebae are often thought to be simple because of their apparent lack of obvious characteristics. Consequently many biologists have the impression that these simple looking organisms are 'primitive' and assume that they are very similar to the first eukaryotes. Preliminary data suggest that there is more complexity and diversity in Amoebozoa than is generally acknowledged. This project is designed to find the relationships among amoebozoans and to develop ideas on how these various amoebae originated from an ancestor whose characteristics were reduced. Given that Amoebozoa is the closest lineage to our own, their ancestry and evolution is important to better understand how all eukaryotes evolved.This research challenges the idea that amoebae are primitively simple. It uses synthetic studies that employ a whole life cycle approach using gene expression profiling and morphological data to address the patterns of broad scale evolution in this highly diverse major eukaryotic lineage. Although amoebozoans occur in nearly every environment, surprisingly little is known about their evolution. This is complicated by the fact that Amoebozoa is under represented in genomic-level databases, and although some recent progress has been made, much more is needed. This project will first develop a robust phylogenetic tree of Amoebozoa under a phylogenomic framework using RNAseq data from taxa broadly sampled across the breadth of the amoebozoan diversity. Additionally, for taxa that display complex life cycles researchers will examine gene expression profiles of various life stages using single cell RNA sequencing techniques. These data will identify commonalties among higher-level amoebozoan groups and by mapping character trait evolution on the tree of Amoebozoa, it will uncover the macroevolutionary trajectories of Amoebozoa. Moreover, this project will examine gene transfer events, gene innovations, gene family expansions and gene losses in Amoebozoa. This represents a unique opportunity to examine the evolution trajectory in which many of the taxa observed today evolved from complex ancestors to more 'simple' terminal taxa. The project will train undergraduate and graduate student training from underrepresented groups in genomics, phylogenetics and Amoebozoa biology.