Split Genes

Genomic and transcriptomic analyses have revealed an unexpected complexity of genes in diverse living organisms. In eukaryotes, most protein-coding genes are interrupted by intronic sequences, which split the genes into multiple exons. Most of these genes undergo a process called 'alternative splicing', in which cis-encoded exons are joined in different combinations to produce various messenger RNAs (mRNAs). Some eukaryotic mRNAs and archaeal tRNAs are produced by the trans-splicing of multiple transcripts expressed from distinct genes. In this article, we introduce the different modes of gene splitting found in the Eukaryotes and the Archaea and discuss their possible roles in biological systems.