RT Journal Article SR Electronic T1 Population genomics of Saccharomyces cerevisiae human isolates: passengers, colonizers, invaders JF bioRxiv FD Cold Spring Harbor Laboratory SP 001891 DO 10.1101/001891 A1 Carlotta De Filippo A1 Monica Di Paola A1 Irene Stefanini A1 Lisa Rizzetto A1 Luisa Berná A1 Matteo Ramazzotti A1 Leonardo Dapporto A1 Damariz Rivero A1 Ivo G. Gut A1 Marta Gut A1 Mónica Bayés A1 Jean-Luc Legras A1 Roberto Viola A1 Cristina Massi-Benedetti A1 Antonella De Luca A1 Luigina Romani A1 Paolo Lionetti A1 Duccio Cavalieri YR 2014 UL http://biorxiv.org/content/early/2014/01/17/001891.abstract AB The quest for the ecological niches of Saccharomyces cerevisiae ranged from wineries to oaks and more recently to the gut of Crabro Wasps. Here we propose the role of the human gut in shaping S. cerevisiae evolution, presenting the genetic structure of a previously unknown population of yeasts, associated with Crohn’s disease, providing evidence for clonal expansion within human’s gut. To understand the role of immune function in the human-yeast interaction we classified strains according to their immunomodulatory properties, discovering a set of genetically homogeneous isolates, capable of inducing anti-inflammatory signals via regulatory T cells proliferation, and on the contrary, a positive association between strain mosaicism and ability to elicit inflammatory, IL-17 driven, immune responses. The approach integrating genomics with immune phenotyping showed selection on genes involved in sporulation and cell wall remodeling as central for the evolution of S. cerevisiae Crohn’s strains from passengers to commensals to potential pathogens.