Intron and gene size expansion during nervous system evolution

• Published in: BMC genomics Vol. 21; no. 1; pp. 360 - 9
• Main Authors: McCoy, Matthew J., Fire, Andrew Z.
• Format: Journal Article
• Language: English
• Published: London BioMed Central 14.05.2020; BioMed Central Ltd; BMC
• Subjects: Adaptive radiation; Animal Genetics and Genomics; Animals; Biomedical and Life Sciences; Cell adhesion & migration; Comparative and evolutionary genomics; Complexity; Evolution; Evolution, Molecular; Gene expression; Gene Expression Regulation; Gene regulation; Gene size; Genes; Genes - genetics; Genome - genetics; Genome evolution; Genomes; Genomics; Insects; Intron size; Introns - genetics; Invertebrates; Life Sciences; Long genes; Long introns; Microarrays; Microbial Genetics and Genomics; Mutation; Nervous System; Nervous system evolution; Neurons; Organ Specificity; Phylogeny; Plant Genetics and Genomics; Proteomics; Research Article; Vertebrates; Intron size; Long genes; Nervous system evolution; Long introns; Genome evolution; Gene size
• ISSN: 1471-2164; 1471-2164
• DOI: 10.1186/s12864-020-6760-4

Background The evolutionary radiation of animals was accompanied by extensive expansion of gene and genome sizes, increased isoform diversity, and complexity of regulation. Results Here we show that the longest genes are enriched for expression in neuronal tissues of diverse vertebrates and of invertebrates. Additionally, we show that neuronal gene size expansion occurred predominantly through net gains in intron size, with a positional bias toward the 5′ end of each gene. Conclusions We find that intron and gene size expansion is a feature of many genes whose expression is enriched in nervous systems. We speculate that unique attributes of neurons may subject neuronal genes to evolutionary forces favoring net size expansion. This process could be associated with tissue-specific constraints on gene function and/or the evolution of increasingly complex gene regulation in nervous systems.