Parallel evolution of a splicing program controlling neuronal excitability in flies and mammals

• Published in: Science advances Vol. 8; no. 4; p. eabk0445
• Main Authors: Torres-Méndez, Antonio, Pop, Sinziana, Bonnal, Sophie, Almudi, Isabel, Avola, Alida, Roberts, Ruairí J V, Paolantoni, Chiara, Alcaina-Caro, Ana, Martín-Anduaga, Ane, Haussmann, Irmgard U, Morin, Violeta, Casares, Fernando, Soller, Matthias, Kadener, Sebastian, Roignant, Jean-Yves, Prieto-Godino, Lucia, Irimia, Manuel
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 28.01.2022
• Subjects: Alternative Splicing; Animals; Biomedicine and Life Sciences; Drosophila - genetics; Drosophila - metabolism; Drosophila Proteins - genetics; Evolutionary Biology; Mammals - genetics; Mammals - metabolism; Mice; Nerve Tissue Proteins - genetics; Neurons - metabolism; RNA Splicing; RNA-Binding Proteins; SciAdv r-articles; Systems Biology
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.abk0445

Alternative splicing increases neuronal transcriptomic complexity throughout animal phylogeny. To delve into the mechanisms controlling the assembly and evolution of this regulatory layer, we characterized the neuronal microexon program in and compared it with that of mammals. In nonvertebrate bilaterians, this splicing program is restricted to neurons by the posttranscriptional processing of the (eMIC) domain in . In , this processing is dependent on regulation by Elav/Fne. eMIC deficiency or misexpression leads to widespread neurological alterations largely emerging from impaired neuronal activity, as revealed by a combination of neuronal imaging experiments and cell type-specific rescues. These defects are associated with the genome-wide skipping of short neural exons, which are strongly enriched in ion channels. We found no overlap of eMIC-regulated exons between flies and mice, illustrating how ancient posttranscriptional programs can evolve independently in different phyla to affect distinct cellular modules while maintaining cell-type specificity.