Diel regulation of metabolic functions of a western Lake Erie Microcystis bloom informed by metatranscriptomic analysis
Year: 2016
Type: article
Abstract: Despite the global prevalence and apparent increased frequency of freshwater cyanobacterial harmful algal blooms (cHABs), metabolic functions that promote cHAB formation and maintenance remain poorly understood.An opportunity to elucidate cellular responses over diel cycles was presented following the 2014 Toledo (OH, USA) water crisis as part of a 48-h Lagrangian survey following toxin-producing bloom biomass in western Lake Erie.Taxonomic analysis of samples collected from 1 m depth showed the bloom to be dominated by three major phyla: Cyanobacteria (~30%), Proteobacteria (~30%), and Bacteroidetes (~20%).Differential expression analysis of Microcystis reads revealed strong diel patterns of expression between day (10:00 h, 16:00 h) and night (22:00 h, 04:00 h) samples.Day transcripts were abundant in functions related to photosynthesis (e.g.psbA, cpcB), nutrient and energy metabolism (glnA, nirA), cell division (ftsH), heat shock response (dnaK, clpB), and nutrient and ion transporters (bicA, acrB).Night transcripts included microcystin synthesis, amino acid synthesis (carB), and pre-dawn expression of photosynthetic antennae (chlI, cbiE).Hierarchical clustering and PCA showed a uniform grouping of expressed genes at night, whereas day transcripts were separated over the 48-h duration.Lack of uniform clustering of day transcripts suggests that the functional partitioning of gene expression during a Microcystis bloom is not limited to circadian regulation, but also to physico-chemical changes within the environment.I would like to dedicate this thesis to girls everywhere, you can do anything.
Author: Emily J. Davenport
Institution: Bowling Green State University
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2598302399