{"id":{"repo_id":"calgary","oai_identifier":"oai:ucalgary.scholaris.ca:1880/123371"},"canonical_url":"https://search.dev.ndltd.org/etd/calgary/oai:ucalgary.scholaris.ca:1880/123371","repository":{"repo_id":"calgary","name":"University of Calgary","base_url":"https://ucalgary.scholaris.ca/server/oai/request"},"display":{"title":"The Role of the Mismatch DNA Repair Protein MutL in Antigenic Variation of the Lyme Disease Spirochete","abstract":"Antigenic variation is one of the immune evasion mechanisms employed by Borrelia burgdorferi to establish a persistent infection in the host through changes of its outer membrane lipoprotein, VlsE, by recombinational events at the vls locus. A recent study identified a requirement for the endonuclease activity of MutL, a canonical DNA mismatch repair protein, for vlsE gene conversion raising the question whether MutL might play a role in recombination or in antigenic variation systems in other bacteria. The aim of this study was to investigate the recombination activity of MutL using B. burgdorferi complementation experiments. I have shown that nanopore sequencing can be used as an expedient method for measuring gene conversion at vlsE that surpasses previously described methods. Current results indicate that MutL from relapsing fever Borrelia species but not from Treponema pallidum or Leptospira interrogans can promote recombination at vlsE in B. burgdorferi suggesting that Borrelia developed a novel sophisticated recombinational switching system to avoid immunosurveillance in a vertebrate host using MutL.","abstract_html":"Antigenic variation is one of the immune evasion mechanisms employed by Borrelia burgdorferi to establish a persistent infection in the host through changes of its outer membrane lipoprotein, VlsE, by recombinational events at the vls locus. A recent study identified a requirement for the endonuclease activity of MutL, a canonical DNA mismatch repair protein, for vlsE gene conversion raising the question whether MutL might play a role in recombination or in antigenic variation systems in other bacteria. The aim of this study was to investigate the recombination activity of MutL using B. burgdorferi complementation experiments. I have shown that nanopore sequencing can be used as an expedient method for measuring gene conversion at vlsE that surpasses previously described methods. Current results indicate that MutL from relapsing fever Borrelia species but not from Treponema pallidum or Leptospira interrogans can promote recombination at vlsE in B. burgdorferi suggesting that Borrelia developed a novel sophisticated recombinational switching system to avoid immunosurveillance in a vertebrate host using MutL.","abstract_has_math":false,"creators":["Shcherbakova, Aleksandra"],"institution":"Cumming School of Medicine","degree_name":"Master of Science (MSc)","degree_level":null,"degree_discipline":"Medicine – Biochemistry and Molecular Biology","degree_department":null,"school":null,"contributors":[],"advisors":["Chaconas, George"],"committee_chairs":[],"committee_members":["Devinney, Rebekah","Billon, Pierre","Williams, Gareth"],"year":2025,"date_issued":"2025-12-10","date_published":"2025-12-10","updated_at":"2026-07-24T01:30:22Z","subjects":[],"languages":["en"],"rights":["Unless otherwise indicated, this material is protected by copyright and has been made available with authorization from the copyright owner. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. 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A recent study identified a requirement for the endonuclease activity of MutL, a canonical DNA mismatch repair protein, for vlsE gene conversion raising the question whether MutL might play a role in recombination or in antigenic variation systems in other bacteria. The aim of this study was to investigate the recombination activity of MutL using B. burgdorferi complementation experiments. I have shown that nanopore sequencing can be used as an expedient method for measuring gene conversion at vlsE that surpasses previously described methods. Current results indicate that MutL from relapsing fever Borrelia species but not from Treponema pallidum or Leptospira interrogans can promote recombination at vlsE in B. burgdorferi suggesting that Borrelia developed a novel sophisticated recombinational switching system to avoid immunosurveillance in a vertebrate host using MutL."]},{"key":"dc:title","label":"Title","values":["The Role of the Mismatch DNA Repair Protein MutL in Antigenic Variation of the Lyme Disease Spirochete"]}]}],"canonical_facts":{"dc:contributor.advisor":["Chaconas, George"],"dc:contributor.committeemember":["Devinney, Rebekah","Billon, Pierre","Williams, Gareth"],"dc:creator":["Shcherbakova, Aleksandra"],"dc:date":["2026-02"],"dc:date.accessioned":["2025-12-12T20:27:50Z"],"dc:date.issued":["2025-12-10"],"dc:description.abstract":["Antigenic variation is one of the immune evasion mechanisms employed by Borrelia burgdorferi to establish a persistent infection in the host through changes of its outer membrane lipoprotein, VlsE, by recombinational events at the vls locus. 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Current results indicate that MutL from relapsing fever Borrelia species but not from Treponema pallidum or Leptospira interrogans can promote recombination at vlsE in B. burgdorferi suggesting that Borrelia developed a novel sophisticated recombinational switching system to avoid immunosurveillance in a vertebrate host using MutL."],"dc:identifier.doi":["https://dx.doi.org/10.11575/PRISM/50817"],"dc:identifier.uri":["https://hdl.handle.net/1880/123371"],"dc:language.iso":["en"],"dc:rights":["Unless otherwise indicated, this material is protected by copyright and has been made available with authorization from the copyright owner. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission."],"dc:title":["The Role of the Mismatch DNA Repair Protein MutL in Antigenic Variation of the Lyme Disease Spirochete"],"dc:type":["master thesis"],"thesis:degree_discipline":["Medicine – Biochemistry and Molecular Biology"],"thesis:degree_name":["Master of Science (MSc)"],"thesis:institution_name":["University of Calgary"]},"updated_at":"2026-07-24T01:30:22Z"}