Scanning the horizon: deep mutational scanning approaches in virology

Studying the effects of mutations is central to virology. Deep mutational scanning (DMS) is a technique that couples high-throughput mutagenesis with deep sequencing to measure the effects of mutations in pooled assays. When adapted to viruses, DMS accelerates comprehensive measurement of mutational effects across viral genomes, mapping evolutionary constraints on viral proteins. Recently, DMS has been applied to a wider variety of problems in virology and viral evolution, quantifying the effects of mutation across host species, tissue environments, and immunological pressures. Since DMS was first applied to virology, synthetic biology has transformed the engineering of mutational libraries, opening new questions to exploration. With the technology now matured, DMS is poised to transform our understanding of viral evolution in new, exciting ways. This review will synthesize recent technological and conceptual advances in DMS methods being applied to virology, the insights it is yielding, and the opportunities for future studies.