Julia Van Etten, Timothy G. Stephens, Erin Chille, Anna Lipzen, Daniel Peterson, Kerrie Barry, Igor V. Grigoriev, Debashish Bhattacharya
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引用次数: 0
Abstract
Horizontal genetic transfer (HGT) is a common phenomenon in eukaryotic genomes. However, the mechanisms by which HGT-derived genes persist and integrate into other pathways remain unclear. This topic is of significant interest because, over time, the stressors that initially favoured the fixation of HGT may diminish or disappear. Despite this, the foreign genes may continue to exist if they become part of a broader stress response or other pathways. The conventional model suggests that the acquisition of HGT equates to adaptation. However, this model may evolve into more complex interactions between gene products, a concept we refer to as the ‘Integrated HGT Model’ (IHM). To explore this concept further, we studied specialized HGT-derived genes that encode heavy metal detoxification functions. The recruitment of these genes into other pathways could provide clear examples of IHM. In our study, we exposed two anciently diverged species of polyextremophilic red algae from the Galdieria genus to arsenic and mercury stress in laboratory cultures. We then analysed the transcriptome data using differential and coexpression analysis. Our findings revealed that mercury detoxification follows a ‘one gene-one function’ model, resulting in an indivisible response. In contrast, the arsH gene in the arsenite response pathway demonstrated a complex pattern of duplication, divergence and potential neofunctionalization, consistent with the IHM. Our research sheds light on the fate and integration of ancient HGTs, providing a novel perspective on the ecology of extremophiles.
期刊介绍:
Environmental Microbiology provides a high profile vehicle for publication of the most innovative, original and rigorous research in the field. The scope of the Journal encompasses the diversity of current research on microbial processes in the environment, microbial communities, interactions and evolution and includes, but is not limited to, the following:
the structure, activities and communal behaviour of microbial communities
microbial community genetics and evolutionary processes
microbial symbioses, microbial interactions and interactions with plants, animals and abiotic factors
microbes in the tree of life, microbial diversification and evolution
population biology and clonal structure
microbial metabolic and structural diversity
microbial physiology, growth and survival
microbes and surfaces, adhesion and biofouling
responses to environmental signals and stress factors
modelling and theory development
pollution microbiology
extremophiles and life in extreme and unusual little-explored habitats
element cycles and biogeochemical processes, primary and secondary production
microbes in a changing world, microbially-influenced global changes
evolution and diversity of archaeal and bacterial viruses
new technological developments in microbial ecology and evolution, in particular for the study of activities of microbial communities, non-culturable microorganisms and emerging pathogens