Investigating the Role of Introns in Transcription-Associated Mutagenesis in Budding Yeast

2020-04-20T22:10:25Z (GMT) by Cedric Lansangan
Transcription can be a source of mutagenesis. This process is called transcription-associated mutagenesis (TAM). The impact of the presence of introns and their splicing has not been assessed. Here, we found that the presence of a constitutively-active long intron (~1kb in length) in a URA3 reporter gene in budding yeast led to a ~17 fold greater mutation rate compared to the short (310 bp) and no-intron strains. This trend was also seen for galactose-inducible versions of our URA3 strains. Furthermore, the long intron located promoter-distal produced the highest mutation rates among our strains. In addition, the long-intron strains (except for the proximal long strain) exhibited a phenotypic growth lag (i.e. smaller colonies) on uracil-deficient media compared to the short and no intron strains.