The ecology and evolutionary history of the Deinococcaceae family
type: CreativeWork
description: Deinococcus radiodurans is the most studied member of the Deinococcaceae family for its outstanding capability to withstand extreme doses of gamma radiation and prolonged desiccation. D. radiodurans is also type species and the first described member of the Deinococcus genus. It demonstrates approximately 3000 times more radiation resistance capability than humans and 50 times more than Escherichia coli. The remarkable radiation resistance phenotype in D. radiodurans and certain members of this family has established the conventional belief that radiation resistance is the defining characteristic of Deinococcaceae. Consequently, microbiologists used gamma radiation as a pre-culture treatment to enrich radioresistant isolates in environmental samples before cultivation. However, a few studies did not use gamma radiation as an enrichment method and isolated sensitive Deinococcus species. These findings demonstrated that the radiation resistance capacity is highly diverse among Deinococcus species, with variations in the order of magnitude ranging from 1.5 kGy to 15 kGy. Because of this variability, the prevailing view is that genomic data cannot predict radiation resistance and that this phenotype remains without a genotype. Moreover, Deinococcus members have been isolated from diverse environments, including Antarctica, hot springs, deserts, atmospheric dust, animals, and garden soil. Nevertheless, the origins of this ubiquity have remained unexplored. Here, I discuss how the biased isolation methods and focus on highly resistant species created a gap in our understanding of the true ecology and evolution of Deinococcaceae. This thesis addresses this knowledge gap using comparative genomics methods by answering three questions. (I) What factors drive the ubiquity of the Deinococcus species? (ii) What drives the diversity of radiation resistance in the Deinococcus genus, and can we predict this phenotype using genomic data? (iii) How did the radiation resistance pheno…
abstract: Deinococcus radiodurans is the most studied member of the Deinococcaceae family for its outstanding capability to withstand extreme doses of gamma radiation and prolonged desiccation. D. radiodurans is also type species and the first described member of the Deinococcus genus. It demonstrates approximately 3000 times more radiation resistance capability than humans and 50 times more than Escherichia coli. The remarkable radiation resistance phenotype in D. radiodurans and certain members of this family has established the conventional belief that radiation resistance is the defining characteristic of Deinococcaceae. Consequently, microbiologists used gamma radiation as a pre-culture treatment to enrich radioresistant isolates in environmental samples before cultivation. However, a few studies did not use gamma radiation as an enrichment method and isolated sensitive Deinococcus species. These findings demonstrated that the radiation resistance capacity is highly diverse among Deinococcus species, with variations in the order of magnitude ranging from 1.5 kGy to 15 kGy. Because of this variability, the prevailing view is that genomic data cannot predict radiation resistance and that this phenotype remains without a genotype. Moreover, Deinococcus members have been isolated from diverse environments, including Antarctica, hot springs, deserts, atmospheric dust, animals, and garden soil. Nevertheless, the origins of this ubiquity have remained unexplored. Here, I discuss how the biased isolation methods and focus on highly resistant species created a gap in our understanding of the true ecology and evolution of Deinococcaceae. This thesis addresses this knowledge gap using comparative genomics methods by answering three questions. (I) What factors drive the ubiquity of the Deinococcus species? (ii) What drives the diversity of radiation resistance in the Deinococcus genus, and can we predict this phenotype using genomic data? (iii) How did the radiation resistance pheno…
author: Abbaszadeh, Jaber
keywords: Radiation resistance, Deinococcus, Ecology, Evolution, Deinococcaceae, Radiation sensitivity, Pangenome
license: https://researchcommons.waikato.ac.nz/bitstreams/9f1fa954-cb78-4849-a6c2-68ad6913157b/download
date published: 2024
date modified: 2026-07-24T05:57:52Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato