- Title:
- Comprehensive survey of condition-specific reproductive isolation reveals genetic incompatibility in yeast
- Journal:
- Nature Communications 6, Article number: 7214
- Author(s):
- Hou J, Friedrich A, Gounot JS, Schacherer J.
- Author(s) affiliation:
- Department of Genetics, Genomics and Microbiology, University of Strasbourg/CNRS, UMR7156, 28 rue Goethe, 67083 Strasbourg, France.
- Short description:
- Genetic variation accumulated in different natural populations could occasionally cause deleterious epistatic effects leading to reduced hybrid fitness and intrinsic post-zygotic reproductive isolation. The Dobzhansky–Müller model described such negative epistasis as genetic incompatibility, where independently fixed mutations in allopatric populations could not properly function together when combined in hybrids. Although most prominently studied between closely related species recent efforts have been made to characterize genetic incompatibilities within the same species, and it has been shown that deleterious epistasis segregates readily at an intraspecific scale. The current focus on intraspecific genetic incompatibilities underscores the importance of the ongoing phenotypic consequences of genetic diversity within an inter-mating population, and captures the evolutionary origin of the early onset of reproductive isolation and speciation.
- Link to the journal
Abstract taken from PubMed
- Abstract:
- Genetic variation within a species could cause negative epistasis leading to reduced hybrid fitness and post-zygotic reproductive isolation. Recent studies in yeasts revealed chromosomal rearrangements as a major mechanism dampening intraspecific hybrid fertility on rich media. Here, by analysing a large number of Saccharomyces cerevisiae crosses on different culture conditions, we show environment-specific genetic incompatibility segregates readily within yeast and contributes to reproductive isolation. Over 24% (117 out of 481) of cases tested show potential epistasis, among which 6.7% (32 out of 481) are severe, with at least 20% of progeny loss on tested conditions. Based on the segregation patterns, we further characterize a two-locus Dobzhansky-Müller incompatibility case leading to offspring respiratory deficiency caused by nonsense mutation in a nuclear-encoding mitochondrial gene and tRNA suppressor. We provide evidence that this precise configuration could be adaptive in fluctuating environments, highlighting the role of ecological selection in the onset of genetic incompatibility and reproductive isolation in yeast.
- Link to the paper on PubMed
