The massive development of tools, such as the omics technologies, which allow scientists to look at biological processes on large scales, is a fundamental component of the so-called Systems Biology. This subject studies biological systems in order to achieve a comprehensive and integrated view of their biology (Ideker et al., 2001). For these aims, the complementation of different disciplines such as molecular biology, biochemistry, and
bioinformatics is of key importance (Graves & Haystead, 2002). The main purpose of omics is the quantification and characterization of the
complete set of the biological molecules which shape structures, functions and dynamics of cells and organisms (Simò€ et al., 2014). The -ome suffix refers to the whole composition of groups of molecules like nucleic acids, proteins and metabolites at a given time or place: genomics is the study of the genome, transcriptomics is the study of the total RNA, proteomics is the study of the entire set of proteins and metabolomics is the study of the set of low molecular weight metabolites (Smith et al., 2005).
When the analysis is referred to genes, transcripts, proteins or metabolites recovered from environmental samples, which may contain many different
organisms, the recently introduced term meta-omics is used (Valles-Colomer et al., 2016). For instance, metagenomics is defined as the analysis of all the genomes contained in an environmental sample (Thomas et al., 2012). Here we offer an overview of these up-to date tools and present what has
already been done in the study of the lichen symbiosis.
