Exploiting homologous recombination increases SATAY efficiency for loss- and gain-of-function screening

The analysis of large-scale transposon mutant libraries is becoming a method of choice for functional genomics in bacteria and fungi. We previously established SAturated Transposon Analysis in Yeast (SATAY) to uncover genes necessary for growth in any condition in S. cerevisiae (Michel et al., 2017). We present an improved version leveraging homologous recombination to increase transposition efficiency by a factor 10, allowing a single experimenter to rapidly perform several parallel screens. We demonstrate its potential by presenting (1) a comparison of the essential gene sets between two yeast laboratory backgrounds, (2) a comprehensive description of essential genes displaying phenotypic delays - we highlight their common features and propose plausible explanations for this phenomenon -, (3) a genome-wide analysis of loss- and gain-of-function mutations conferring sensitivity or resistance to a compendium of 9 anti-fungal compounds. This study highlights the power of this improved SATAY protocol for yeast functional- and pharmaco-genomics.