Non-coding RNAs in dictyostelium discoideum and other dictyostelid social amoebae

Non-coding (nc)RNAs have recently emerged as ubiquitous and important regulators of a multitude of different processes, such as stress response, cell differentiation, infection, and cell death. The means by which ncRNAs affect these processes are numerous and diverse, ranging from protein localization to regulation of gene expression. ncRNA-mediated gene expression control has been the subject of especially intense study in recent years and has shown to occur through several mechanisms. Different ncRNAs can regulate gene expression transcriptionally by inducing modification of DNA or chromatin, or post-transcriptionally by directing cleavage, degradation, or translational inhibition of messenger (m)RNAs. ncRNAs come in a broad spectrum of sizes, from ~20 nucleotides (nt) to several thousand nt, and function in complexes with various proteins that usually exert a catalytic function while the RNAs act as guides. In Dictyostelia, we have only started to understand the extent of ncRNA regulation, mostly from studies in Dictyostelium discoideum, which is the focus of this chapter.