Saccharomyces paradoxus

Saccharomyces paradoxus is mostly isolated from deciduous trees (oak, maple, birch), and in some rare occasions on insects and fruits. It is often found in sympatry with other Saccharomyces species. Like Saccharomyces cerevisiae, it has a worldwide distribution and it is mesophilic, which limits its natural distribution to low latitudes. However, Saccharomyces paradoxus typically grows at lower temperatures than Saccharomyces cerevisiae, resulting in a slight shift in its distribution toward cooler regions, like British islands and Eastern Canada. ==Biogeography==

'', are genetically indistinguishable but exhibit post-zygotic isolation when crossed to strains from the American population, due to chromosomal translocations. ==Reproduction==

Saccharomyces paradoxus is naturally homothallic, and is mostly found as diploid in the environment. Reproduction is mostly clonal and 99% of sexual reproduction occurs between spores from the same ascus. This purges recessive deleterious mutations that accumulated during clonal expansion, in a process known as "genome renewal". Post-zygotic isolation between strains of Saccharomyces paradoxus is commonly observed and could be either due to genetic divergence between populations or to chromosomal changes within populations. Like in other Saccharomyces species, heterothallism can be restored using standard genetic tools, to obtain stable haploid strains for experimental purposes. == References ==