A single chromosome strain of S. cerevisiae exhibits diminished ethanol metabolism and tolerance.
Level 5 - mechanism / opinion, no new human data
In vitro bench research using an engineered yeast strain (no human data)
PubMed 34551706 · doi:10.1186/s12864-021-07947-x
What was done
The authors characterized the growth, transcriptomic profile, and metabolic flux of an engineered Saccharomyces cerevisiae strain containing a single fused chromosome (with 30 telomeres, >300 kb subtelomeric DNA, and 107 subtelomeric ORFs removed) compared to a reference strain. Phenotypes were tested on YPD medium and under ethanol stress or ethanol as a sole carbon source using growth assays, RNA sequencing, enzyme-constrained metabolic modeling, and rescue experiments with the sirtuin inhibitor nicotinamide.
What was found
Compared to the reference strain, the single-chromosome strain exhibited a longer lag phase, increased doubling time, and lower final biomass concentration on YPD, phenotypes that were amplified in the presence of ethanol or when ethanol was the sole carbon source. RNA sequencing revealed reduced induction of genes involved in diauxic shift, ethanol metabolism, and fatty-acid beta-oxidation. Nicotinamide rescued the ethanol growth defect. The abstract reports no numerical values for growth rates, biomass, or gene expression changes.
Why it matters
This work demonstrates how massive chromosomal fusion and loss of subtelomeric regions can indirectly perturb metabolic regulation and stress tolerance by redistributing sirtuin deacetylases across the genome.
Limits
This is an in vitro model organism study with no direct human or clinical translation. The abstract does not provide exact quantitative values, effect sizes, statistical parameters, or the number of replicates used.
Cited by
- supports Saccharomyces cerevisiae (baker's yeast) cells have 16 linear chromosomes in their haploid state, or 32 when mated and diploid.