Regulatory non-coding small RNAs are diverse and abundant in an extremophilic microbial community

Abstract

1Regulatory small RNAs (sRNAs) represent a major class of regulatory molecules that 2 play large-scale and essential roles in many cellular processes across all domains of 3 life. Microbial sRNAs have been primarily investigated in a few model organisms and 4 little is known about the dynamics of sRNA synthesis in natural environments, and the 5 roles of these short transcripts at the community level. Analyzing the metatranscriptome 6 of a model extremophilic community inhabiting halite nodules (salt rocks) from the 7 Atacama Desert with SnapT -a new sRNA annotation pipeline -we discovered 8 hundreds of intergenic (itsRNAs) and antisense (asRNAs) sRNAs. The halite sRNAs 9were taxonomically diverse with the majority expressed by members of the 10 Halobacteria. We found asRNAs with expression levels negatively correlated with that 11 of their putative overlapping target, suggesting a potential gene regulatory mechanism. 12

Cellular life from the three domains and viruses are transcriptionally active in a hypersaline desert community

“…To address the paucity of knowledge on the transcriptional activities of halophilic microbial communities, we interrogated the metatranscriptome of the well‐characterized halophilic community inhabiting salt nodules in the Atacama Desert (Robinson et al ., 2015; Crits‐Christoph et al ., 2016; Finstad et al ., 2017; Gelsinger et al ., 2019; Uritskiy et al ., 2019). We sampled nodules from representative light and dark time‐points during the diel cycle, placing our transcriptional observations in the context of the metagenomic composition of the respective samples.…”

“…It is also likely that the large relative humidity and temperature changes in the Atacama Desert, throughout the diurnal (day/night) cycle, have a significant impact on microbiome functioning. In that regard, a recent study showed that halite communities have the capability for transcriptional regulation via small non‐coding RNAs (Gelsinger et al ., 2019).…”