Medical Genetics GT-AG rule The predominance of this ' GT- AG rule supports the hypothesis that spliceosomal introns are spliced in yeasts, as in most eukaryotes, by a conserved mechanismMedical Genetics GT-AG rule The predominance of this 'GTAG' rule supports the hypothesis that spliceosomal introns are spliced in yeasts, as in most eukaryotes, by a conserved mechanism