Premium
Generating and characterizing resistance to ionizing radiation in experimentally evolved populations of Escherichia coli .
Author(s) -
Trimarco Joseph D.,
Bruckbauer Steven T.,
Cox Michael M.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.786.4
Subject(s) - biology , dna repair , genetics , dna , population , ionizing radiation , dna damage , transcription (linguistics) , computational biology , physics , medicine , irradiation , nuclear physics , linguistics , philosophy , environmental health
Efficient and accurate DNA repair processes are essential to maintaining genomic integrity. While most DNA repair mechanisms are remarkably effective, extreme sources of DNA damage can overwhelm these processes. One such source is ionizing radiation (IR). Our lab has developed a novel approach to determining the molecular basis of bacterial IR resistance. Using directed evolution, we have generated four populations of IR‐resistant E. coli with high‐energy electron beam IR delivered via a clinical linear accelerator (Linac). The Linac administers controllable and consistent doses of ionizing radiation, allowing for accurate and repeatable conditions of selective pressure. Now at round 90 of selection, we have generated the most IR‐resistant organisms ever produced within a laboratory. Using whole‐population genomic sequencing, we have identified mutations in proteins conducting and regulating DNA repair, transcription, anaerobic metabolism, cell wall biogenesis and amelioration of reactive oxygen species. We have shown mutations in DNA double strand break repair machinery (RecA, RecBCD, RecN) and RNA polymerase (RpoB, RpoC) to confer IR resistance. Using these mutations and others, we describe genetic modifications necessary for nascent mechanisms of IR resistance. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .