Daily rhythmicity in coastal microbial mats.
Christine HörnleinVeronique Confurius-GunsLucas J StalHenk BolhuisPublished in: NPJ biofilms and microbiomes (2018)
Cyanobacteria are major primary producers in coastal microbial mats and provide biochemical energy, organic carbon, and bound nitrogen to the mat community through oxygenic photosynthesis and dinitrogen fixation. In order to anticipate the specific requirements to optimize their metabolism and growth during a day-and-night cycle, Cyanobacteria possess a unique molecular timing mechanism known as the circadian clock that is well-studied under laboratory conditions but little is known about its function in a natural complex community. Here, we investigated daily rhythmicity of gene expression in a coastal microbial mat community sampled at 6 time points during a 24-h period. In order to identify diel expressed genes, meta-transcriptome data was fitted to periodic functions. Out of 24,035 conserved gene transcript clusters, approximately 7% revealed a significant rhythmic expression pattern. These rhythmic genes were assigned to phototrophic micro-eukaryotes, Cyanobacteria but also to Proteobacteria and Bacteroidetes. Analysis of MG-RAST annotated genes and mRNA recruitment analysis of two cyanobacterial and three proteobacterial microbial mat members confirmed that homologs of the cyanobacterial circadian clock genes were also found in other bacterial members of the microbial mat community. These results suggest that various microbial mat members other than Cyanobacteria have their own molecular clock, which can be entrained by a cocktail of Zeitgebers such as light, temperature or metabolites from neighboring species. Hence, microbial mats can be compared to a complex organism consisting of multiple sub-systems that have to be entrained in a cooperative way such that the corpus functions optimally.
Keyphrases
- microbial community
- genome wide
- gene expression
- mental health
- healthcare
- genome wide identification
- climate change
- dna methylation
- physical activity
- heavy metals
- poor prognosis
- human health
- ms ms
- single cell
- rna seq
- transcription factor
- electronic health record
- depressive symptoms
- genome wide analysis
- long non coding rna
- atomic force microscopy
- sleep quality
- mass spectrometry
- high speed