Ellis Torrance

  • Program Year: 2
  • Academic Institution: University of North Carolina, Greensboro
  • Field of Study: Environmental Health Science
  • Academic Advisor: Louis-Marie Bobay
  • Practicum(s): Practicum Not Yet Completed
  • Degree(s):
    B.S. Biology, Portland State University, 2018; A.S. Allied Health, Columbia Junior College, 2012

Summary of Research

When a new bacterium is discovered scientists have previously used a universally shared gene sequence, the 16s rRNA gene, to categorize it to a species. Similar to humans, bacteria have a whole set of genes that encode for different traits that can be compared in a pairwise fashion to give us a better picture of how these bacteria are different and how they are evolving. Importantly, bacteria possess the ability to exchange genes thereby acquiring new traits such as virulence or antibiotic resistance very rapidly. It no longer makes sense to group bacteria by a single gene; however, tackling the problem of comparing all bacterial genes requires a lot of computational power as it is estimated that there are close to a trillion bacterial species on earth with 99.99% yet to be discovered.

To address this problem, one aim of my PhD project with Dr. Louis-marie Bobay is to develop new bioinformatics methods and metrics to characterize gene transfers across large datasets of bacterial genomes (>200,000) to better define gene flux, or recombination, between and within species and to understand how this drives bacterial adaptation. Defining differences in recombination rates amongst bacteria will help us understand the "rules" of bacterial evolution and characterize which species have the highest potential to gain new traits and become harmful to human health - such as genes promoting antibiotic resistance and virulence.

Publications

Pratt, A. A., Torrance, E. L., Kasun, G. W., Stedman, K. M., & de la Higuera, I. (2021). StemLoop-Finder: a Tool for the Detection of DNA Hairpins with Conserved Motifs. Microbiology resource announcements, 10(26), e0042421. https://doi.org/10.1128/MRA.00424-21

Connor D Harris, Ellis L Torrance, Kasie Raymann, Louis-Marie Bobay, CoreCruncher: fast and robust construction of core genomes in large prokaryotic datasets, Molecular Biology and Evolution, , msaa224, https://doi.org/10.1093/molbev/msaa224

Ignacio de la Higuera, George W. Kasun, Ellis L. Torrance, Alyssa A. Pratt, et al., Unveiling Crucivirus Diversity by Mining Metagenomic Data, mBio Sep 2020, 11 (5) e01410-20; DOI: 10.1128/mBio.01410-20

De la Higuera, I., Torrance, E. L., Pratt, A. A., Kasun, G. W., Maluenda, A.,
Stedman, K. M. (2019). Genome Sequences of Three Cruciviruses Found in the
Willamette Valley (Oregon). Microbiology Resource Announcements, 8(23), e00447-19.

Symposium Presentations:

Torrance E, De La Higuera N, Kasun G, Stedman K. Gotta Catch 'em All: Environmental Recovery of Complete Cruciviral Sequences for Comparative Genomics and Host Elucidation. Oral Presentation: Better Know a Lab, Biology Investigations and Outreach Society; 2017. Portland, OR

Torrance E. Going Viral: How Viruses Shape Our World. Oral Presentation: Ladies Lab Night - Women in STEM, The Science Outreach Society; 2018, Portland, OR

Torrance E, De La Higuera N, Kasun G, Stedman K. From the Sequence to the Field: Working to Understand Cruciviral Origins through Sequence Recovery and Host Elucidation. Digital Presentation: Sigma Xi Student Research Showcase; 2018, Online

Torrance E, Stedman K. Microvirus - Macro Story: Exploring Diversity of a Microvirus Partial Genome Recovered from an Oregon Peat Bog. Ronald E. McNair Scholar Symposium; 2018 Portland, OR

Torrance E. 'Trait Analysis and Evolution'. Invited Workshop and Guest Lecture: Union Pines High School; 2020. Cameron, NC

Peeples C, Torrance E, Marsonette B, Lyon C. The Quantitative Effects of Varied Nitrogen Levels on the Rhizobial Symbiosis of P. lunatus and C. Rosea. Poster Presentation: Portland State University's Course-Based Undergraduate Research Symposium; 2017. Portland, OR

Torrance E, De La Higuera N, Stedman K Analysis of Complete Cruciviral Sequences for Comparative Genomics and Host Elucidation. Poster Presentation: Sigma Xi Columbia-Willamette 14th Annual Student Research Symposium; 2017. Portland, OR

Torrance E, De La Higuera N, Kasun G, Stedman K. Environmental Recovery of Complete Cruciviral Sequences for Comparative Genomics and Host Elucidation. Poster Presentation: American Society for Virology 2018 Annual Meeting; 2018, College Park, Maryland

Torrance E, De La Higuera N, Kasun G, Stedman K. Environmental Recovery of Complete Cruciviral Sequences for Comparative Genomics and Host Elucidation. Poster Presentation: U.S. DOE Joint Genome Institute Microbial and Metagenomics Workshop; 2018 Walnut Creek, CA

Torrance E, Diop A., Burton C., Bobay LM. Sex Isn't Everything: Estimating Recombination Rates Across Bacterial Lineages: Duke University Research Computing Symposium; 2020 Durham, NC

Torrance E.L., Diop A., Bobay LM. Estimating the Contribution and Variation of Adaptive Evolution Across Bacterial Species, American Society of Microbiology (ASM) World Microbe Forum; 2021 International Virtual Conference

Torrance E.L., Diop A., Bobay LM. Bacteria Don't Remain Neutral on the Matter: Differential Contribution of Adaptive Evolution Across Bacterial Species, Society for Molecular Biology and Evolution (SMBE), SMBEv2021, 2021 International Virtual Conference

Awards

First Place - Communicate Your Science and Engineering (CYSE) Essay Contest, 2021 - Title: "Sex Isn't Everything"
Department of Energy Computational Science Graduate Fellowship (DOE CSGF) 2020-Present
Graduate Research Fellowship Program (GRFP) Honorable Mention National Science
Foundation (NSF) 2019
Portland State University McNair Scholar 2017-2018 Ronald E. McNair Research
Funding and Scholarship
Cum Laude Honors - Portland State University BS in Biology with Chemistry Minor
First Place Award in Undergraduate Biology Division Sigma Xi C-W 14 th Annual
Student Research Symposium November 14, 2017
Sigma Xi Research Honors Society Membership Award November 14, 2017
ASV Travel Grant Award Recipient 2018 Annual Meeting at University of Maryland,
American Society for Virology
AAAS and Sigma Xi Pacific Division Travel Grant AAAS 99 th Annual Meeting at Cal
Poly Pomona
C-W Sigma Xi Travel Grant Award Recipient 2018 Annual Meeting at University of
Maryland, American Society for Virology
Dean's list Spring and Fall 2016
President's List Summer 2016
Portland State University Access Grant: 2015-2017
Oregon Opportunity Grant (ORSNG): 2013-2018
Federal Pell Grant: 2013-2018