Genomic analysis of Saccharomyces cerevisiae isolates that grow optimally with glucose as the sole carbon source

Authors

  • Anthony D. Aragon,

    1. UNM Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, NM, USA
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  • Norah Torrez-Martinez,

    1. UNM Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, NM, USA
    2. UNM Cancer Center, University of New Mexico, Albuquerque, NM, USA
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  • Jeremy S. Edwards

    Corresponding author
    1. UNM Cancer Center, University of New Mexico, Albuquerque, NM, USA
    2. Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, NM, USA
    • UNM Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, NM, USA
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Correspondence: Professor Jeremy S. Edwards, UNM Department of Molecular Genetics and Microbiology, University of New Mexico, 915 Camino de Salud NE, Albuquerque, NM 87131, USA

E-mail: jsedwards@salud.unm.edu

Fax: +1 505-272-6029

Abstract

A population of Saccharomyces cerevisiae was cultured for approximately 450 generations in the presence of high glucose to select for genetic variants that grew optimally under these conditions. Using the parental strain BY4741 as the starting population, an evolved culture was obtained after aerobic growth in a high glucose medium for approximately 450 generations. After the evolution period, three single colony isolates were selected for analysis. Next-generation Ion Torrent sequencing was used to evaluate genetic changes. Greater than 100 deletion/insertion changes were found with approximately half of these effecting genes. Additionally, over 180 SNPs were identified with more than one-quarter of these resulting in a nonsynonymous mutation. Affymetrix DNA microarrays and RNseq analysis were used to determine differences in gene expression in the evolved strains compared to the parental strain. It was established that approximately 900 genes demonstrated significantly altered expression in the evolved strains relative to the parental strain. Many of these genes showed similar alterations in their expression in all three evolved strains. Interestingly, genes with altered expression in the three evolved strains included genes with a role in oxidative metabolism. Overall these results are consistent with the physiological observations of optimal growth with glucose as the carbon source. Namely, the decreased ethanol production suggest that the underlying metabolism switched from fermentation to respiration during the selection for optimal growth on glucose.

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