Search and analysis of important lncRNAs (long non-coding RNAs) to the ethanol tolerance in Saccharomyces cerevisiae

The yeast Saccharomyces cerevisiae is the most used microorganism for ethanol production due to its high fermentative capacity and resistance to different stressors along this process. However, the ethanol concentration is one of the most limiting factors of fuel production. The functional genomics aspects related to the ethanol tolerance are still unclear, and it is not clear if the lncRNAs really have a role in this process. Few lncRNAs were identified in S. cerevisiae, lncRNA-protein networks of this species are still unknown and also if they can code micropeptides. In this context, this thesis aims to identify lncRNAs and evaluate their roles in S. cerevisiae ethanol tolerance. Then, it was performed the assembling of lncRNAs, predictions of lncRNA-protein interactions, searches for potential micropeptides coding-lncRNAs, analysis of genomic, structural and functional conservation of lncRNAs, evaluation of the lncRNAs influence in regulating the expressions of their neighbors, and comparison between strains that are more and less tolerant to the ethanol. Moreover, many putative regulatory pathways were here suggested, being that most trans regulations act on an inversely manner between the expression of the lncRNAs and their target-genes, unlike observed in most of cis regulations. The current literature confirms the lncRNAs functional conservation here observed, and the role of these non-coding molecules as regulators. Finally, here we suggest that lncRNAs are acting to overcome the stress caused by the highest ethanol concentration. (AU)