Competition experiments in a soil microcosm reveal the impact of genetic and biotic factors on natural yeast populations

• Published in: The ISME Journal Vol. 14; no. 6; pp. 1410 - 1421
• Main Authors: Bleuven, Clara, Nguyen, Guillaume Q., Després, Philippe C., Filteau, Marie, Landry, Christian R.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-06-2020; Nature Publishing Group
• Subjects: 45/23; 45/77; 631/158/855; 631/326/2565; Bar codes; Biodiversity; Biomedical and Life Sciences; Biotic factors; Deoxyribonucleic acid; DNA; Ecology; Evolutionary Biology; Fitness; Gene sequencing; Irradiation; Life Sciences; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Microorganisms; Populations; Quercus - growth & development; Quercus - microbiology; Radiation; Reproductive fitness; Saccharomyces - genetics; Saccharomyces - growth & development; Saccharomyces - isolation & purification; Soil - chemistry; Soil Microbiology; Soils; Yeast; Yeasts
• ISSN: 1751-7362; 1751-7370
• DOI: 10.1038/s41396-020-0612-8

The ability to measure microbial fitness directly in natural conditions and in interaction with other microbes is a challenge that needs to be overcome if we want to gain a better understanding of microbial fitness determinants in nature. Here we investigate the influence of the natural microbial community on the relative fitness of the North American populations
SpB
,
SpC
and
SpC*
of the wild yeast
Saccharomyces paradoxus
using DNA barcodes and a soil microcosm derived from soil associated with oak trees. We find that variation in fitness among these genetically distinct groups is influenced by the microbial community. Altering the microbial community load and diversity with an irradiation treatment significantly diminishes the magnitude of fitness differences among populations. Our findings suggest that microbial interactions could affect the evolution of yeast lineages in nature by modulating variation in fitness.