Lydia Bright
Postdoctoral Research Associate
lybright(at)indiana.edu
(812) 856-0115
Ph.D. 2011 Molecular Genetics and Cell Biology, University of Chicago
B.A. 1999 Biology and Studio Art, Oberlin College
Research
I am interested in using current genomic and evolutionary approaches to uncover how fine-scale mechanisms of evolution shape subcellular processes in eukaryotic cells. I am combiningcell biological and evolutionary approaches, using members of the Paramecium aurelia species complex, to better understand these subcellular processes, particularly those involved in membrane trafficking.
Specifically, I am tracing how protein determinants involved in membrane trafficking in Paramecium species have, in their duplication and diversification, shaped subcellular function in different lineages. In membrane trafficking, each step is controlled by specific protein determinants and their effectors, which together direct fission and fusion of vesicles and compartments. These trafficking determinants are often found in large gene families, whose size is correlated with the number of specific trafficking steps found in that particular eukaryotic cell. The duplication and diversification of members of these gene families are closely tied with the diversification of trafficking pathways and with increasing cellular complexity in different lineages. By exploring exactly how members of these gene families have changed in sequence, localization and function in closely-related species, I hope to learn more about the evolution of trafficking pathways at a detailed level.
The Paramecium aurelia complex is a promising system in which to follow patterns of gene duplication, preservation and loss. The Lynch lab is currently sequencing the genomes of all members of the aurelia complex; this newly available genomic information presents an exciting opportunity to begin genetic and cell biological work within and among all of these species.
Some of the protein families I'm exploring include Rab GTPases, SNAREs, and adaptor protein subunits.
Intertwined with questions of gene family evolution are questions of how specific motifs and domains in proteins, which contribute to their phylogenetic classification into subfamilies, affect localization and function. In the future I plan to pursue questions related to specific motifs and their evolution through analysis of signatures of selection across regions of proteins, as well as through mutational analysis of specific motifs in cells.
My thesis work included a comprehensive look at the Rab GTPase family in Tetrahymena thermophila:
Bright, L, Kambesis N., Nelson SB, Jeong B, and AP Turkewitz. (2010). Comprehensive Analysis Reveals Dynamic and Evolutionary Plasticity of Rab GTPases and Membrane Traffic in Tetrahymena thermophila. PLoS Genetics, 14 Oct 2010.