How did alternative splicing evolve?
Alternative splicing creates transcriptome diversification, possibly leading to speciation. A large fraction of the protein-coding genes of multicellular organisms are alternatively spliced, although no regulated splicing has been detected in unicellular eukaryotes such as yeasts. A comparative analysis of unicellular and multicellular eukaryotic 5' splice sites has revealed important differences - the plasticity of the 5' splice sites of multicellular eukaryotes means that these sites can be used in both constitutive and alternative splicing, and for the regulation of the inclusion/skipping ratio in alternative splicing. So, alternative splicing might have originated as a result of relaxation of the 5' splice site recognition in organisms that originally could support only constitutive splicing.
Ast
Gil
G
Department of Human Genetics and Molecular Medicine, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel. gilast@post.tau.ac.il
D017398:Alternative Splicing / Q000235:genetics*; D020029:Base Pairing / Q000235:genetics; D019143:Evolution, Molecular; D007438:Introns / Q000235:genetics; D008957:Models, Genetic; D022821:RNA Splice Sites / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*
D022821:RNA Splice Sites; D012333:RNA, Messenger