Using local GC percentage to detect unusual regions in bacterial genomes

• In Event: Poster Presentation and Judging for: Biomedical; Cell & Molecular Biology; Chemistry & Biochemistry; Marine Science; Systematics & Evolutionary Biology.
  In Poster Session: Chemistry & Biochemistry Poster Session

Abstract

Development of new antibiotics may include strategies such as identifying unique genes that may serve as an antibiotic target, or previously unidentified similarities between an antibiotic resistant organism and other organisms that have well-known treatments. As a new approach to find these features, we examined the genomes of 28 bacterial organisms at a “local” level to find regions that seemed dissimilar to the rest of the genome. Local GC percentages were defined as the percentage of guanine and cytosine across 210 base pairs, and these local GC percentages were calculated at 70 base pair intervals across the entire genomes of the organisms. Median and quartiles for the local GC percentages of all of the organisms were also determined. While most organisms’ local GC percentages remained within a certain range, some organisms showed interesting characteristics where this was not the case. For example Mycobacterium tuberculosis had a much larger range than the other Mycobacteria, and the bacteria from the Clostridium genus had extreme spikes in GC percentage extending as much as 20% outside of its typical range. Some of these anomalous areas of the genome could be examined to identify potential sites of horizontal gene transfer or other unique features of an organism that may lead to new targets for antibiotic development.

Authors

• Sharon Leigh Ann DeMerritt, Wayland Baptist University

• Gracia Sebastiao, Wayland Baptist University

• Robert L Moore, Wayland Baptist University