Authors: Abdullah M, Greco BM, Laurent JM, Garge RK, Boutz DR, Vandeloo M, Marcotte EM, Kachroo AH
A major challenge to rationally building multi-gene processes in yeast arises due to the combinatorics of combining all of the individual edits into the same strain. Here, we present a precise and multi-site genome editing approach that combines all edits without selection markers using CRISPR-Cas9. We demonstrate a highly efficient gene drive that selectively eliminates specific loci by integrating CRISPR-Cas9-mediated double-strand break (DSB) generation and homology-directed recombination with yeast sexual assortment. The method enables marker-less enrichment and recombination of genetically engineered loci (MERGE). We show that MERGE converts single heterologous loci to homozygous loci at ~100% efficiency, independent of chromosomal location. Furthermore, MERGE is equally efficient at converting and combining multiple loci, thus identifying compatible genotypes. Finally, we establish MERGE proficiency by engineering a fungal carotenoid biosynthesis pathway and most of the human a-proteasome core into yeast. Therefore, MERGE lays the foundation for scalable, combinatorial genome editing in yeast.
Keywords: CRISPR-Cas9; combinatorial ; genome editing; gene drive; humanized proteasome; humanized yeast;
PubMed: https://pubmed.ncbi.nlm.nih.gov/37323580/
DOI: 10.1016/j.crmeth.2023.100464