Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Ireland
Smurfit Institute of Genetics, University of Dublin, Trinity College
This a model from the article: Increased glycolytic flux as an outcome of whole-genome duplication in yeast. Conant GC, Wolfe KH Mol. Syst. Biol. [2007 ; Volume: 3 (Issue: )]: 129 17667951 , Abstract: After whole-genome duplication (WGD), deletions return most loci to single copy. However, duplicate loci may survive through selection for increased dosage. Here, we show how the WGD increased copy number of some glycolytic genes could have conferred an almost immediate selective advantage to an ancestor of Saccharomyces cerevisiae, providing a rationale for the success of the WGD. We propose that the loss of other redundant genes throughout the genome resulted in incremental dosage increases for the surviving duplicated glycolytic genes. This increase gave post-WGD yeasts a growth advantage through rapid glucose fermentation; one of this lineage's many adaptations to glucose-rich environments. Our hypothesis is supported by data from enzyme kinetics and comparative genomics. Because changes in gene dosage follow directly from post-WGD deletions, dosage selection can confer an almost instantaneous benefit after WGD, unlike neofunctionalization or subfunctionalization, which require specific mutations. We also show theoretically that increased fermentative capacity is of greatest advantage when glucose resources are both large and dense, an observation potentially related to the appearance of angiosperms around the time of WGD. This model reproduces fig. 2C from the corrigendum to the publication The parameter Vmax_PDH was corrected by a factor 60 from 6.32 mM/min in the publication to 379.2 mM/min in accordance with the authors. see the corrigendum at msb or its pubmed entry (pmid:18594520) This model comprises the glycolysis model from Pritchard and Kell (2002) with an extension for the metabolisation of pyruvate in the mitochondria by pyruvate dehydrogenase and an additional parameter, WGD_E , to adjust for the differing enzyme concentrations before the whole genome duplication (WGD). To switch off transport of pyruvate to the mitochondria, set the parameter t_m = 0. Figure 2C from the article can be reproduced by manually changing the value of parameter WGD_E in the range between 0.65 and 1.0 and calculating the ratios of ratio of PDC/PDH fluxes in the altered model to the one of the model with WGD_E = 1. This model originates from BioModels Database: A Database of Annotated Published Models (http://www.ebi.ac.uk/biomodels/). It is copyright (c) 2005-2012 The BioModels.net Team. For more information see the terms of use . To cite BioModels Database, please use: Li C, Donizelli M, Rodriguez N, Dharuri H, Endler L, Chelliah V, Li L, He E, Henry A, Stefan MI, Snoep JL, Hucka M, Le Novère N, Laibe C (2010) BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models. BMC Syst Biol., 4:92.