title: Induced mutations in yeast cell populations adapting to an unforeseen challenge.
abstract: The modern evolutionary synthesis assumes that mutations occur at random, independently of the environment in which they confer an advantage. However, there are indications that cells facing challenging conditions can adapt rapidly, utilizing processes beyond selection of pre-existing genetic variation. Here, we show that a strong regulatory challenge can induce mutations in many independent yeast cells, in the absence of general mutagenesis. Whole genome sequencing of cell lineages reveals a repertoire of independent mutations within a single lineage that arose only after the cells were exposed to the challenging environment, while other cells in the same lineage adapted without any mutation in their genomes. Thus, our experiments uncovered multiple alternative routes for heritable adaptation that were all induced in the same lineage during a short time period. Our results demonstrate the existence of adaptation mechanisms beyond random mutation, suggesting a tight connection between physiological and genetic processes.
authors.affiliation: Department of Physics & Network Biology Research Laboratories, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Lindsay S
authors.initials: LS
authors.lastname: Moore
authors.affiliation: Stanford Genome Technology Center, Palo Alto, California, United States of America.
authors.forename: Wu
authors.initials: W
authors.lastname: Wei
authors.affiliation: Department of Physics & Network Biology Research Laboratories, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Elad
authors.initials: E
authors.lastname: Stolovicki
authors.affiliation: Department of Animal Sciences, The Hebrew University of Jerusalem, Rehovot, Israel.
authors.forename: Tamar
authors.initials: T
authors.lastname: Benbenishty
authors.affiliation: European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wilkening
authors.affiliation: Stanford Genome Technology Center, Palo Alto, California, United States of America; European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany.
authors.forename: Lars M
authors.initials: LM
authors.lastname: Steinmetz
authors.affiliation: Department of Physics & Network Biology Research Laboratories, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Erez
authors.initials: E
authors.lastname: Braun
authors.affiliation: Department of Animal Sciences, The Hebrew University of Jerusalem, Rehovot, Israel.
authors.forename: Lior
authors.initials: L
authors.lastname: David
mesh_terms: D000222:Adaptation, Physiological; D001786:Blood Glucose / Q000737:chemistry; D002469:Cell Separation; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D005434:Flow Cytometry; D005690:Galactose / Q000737:chemistry; D014644:Genetic Variation; D016681:Genome, Fungal; D015994:Incidence; D009154:Mutation; D016366:Open Reading Frames; D011110:Polymorphism, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D001786:Blood Glucose; D005690:Galactose