Sex, outcrossing and mating types: unsolved questions in fungi and beyond

@article{Billiard2012SexOA,
  title={Sex, outcrossing and mating types: unsolved questions in fungi and beyond},
  author={Sylvain Billiard and Manuela Lopez-Villavicencio and Michael E. Hood and Tatiana Giraud},
  journal={Journal of Evolutionary Biology},
  year={2012},
  volume={25}
}
Variability in the way organisms reproduce raises numerous, and still unsolved, questions in evolutionary biology. In this study, we emphasize that fungi deserve a much greater emphasis in efforts to address these questions because of their multiple advantages as model eukaryotes. A tremendous diversity of reproductive modes and mating systems can be found in fungi, with many evolutionary transitions among closely related species. In addition, fungi show some peculiarities in their mating… 
The frequency of sex in fungi
  • B. Nieuwenhuis, T. James
  • Biology, Medicine
    Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2016
TLDR
How population genetic methods can be used to estimate the frequency of sex in fungi and empirical data that support a mixed mode of reproduction in many species with rare to frequent sex in between rounds of mitotic reproduction are reviewed.
Evolution of uni- and bifactorial sexual compatibility systems in fungi
TLDR
An overview of the evolutionary factors that might have driven the evolution of bifactoriality from a unifactorial system and the transitions back to unfactoriality is given.
Deleterious effects of recombination and possible nonrecombinatorial advantages of sex in a fungal model
TLDR
The fungus Aspergillus nidulans was used to experimentally test predictions of the hypothesis that sex could be maintained in the short term by advantages due to functions linked with sex, but not related to recombination, and results were consistent with these hypotheses.
Genetic diversity in facultatively sexual populations and its implications for the origins of self-incompatibility in algae and fungi
TLDR
Although populations with mating types successfully engage in sexual reproduction less frequently than their self-compatible competitors, they can nevertheless engage in useful sex with genetically distinct partners more frequently, and the potential for frequency-dependent selection in competitive dynamics between self- compatible and self-incompatible types is demonstrated.
Contrasted patterns in mating-type chromosomes in fungi: hotspots versus coldspots of recombination.
TLDR
F fungi are pointed to as a fascinating group for studying the various evolutionary forces at play in the genomic regions involved in mating compatibility.
Why outcross? The abandon-ship hypothesis in a facultative outcrossing/selfing fungal species.
TLDR
The results strongly support the abandon-ship hypothesis and suggest that, for parents with low fitness, the costs of investing in sexual reproduction may be compensated by the production of fitter progeny carrying beneficial allele combinations.
Clonal reproduction in fungi
TLDR
This work examines intrinsic restraints on recombination associated with mating systems that range from strictly clonal at one extreme to fully outbreeding at the other and those that lie between, including selfing and inbreeding and considers a recent hypothesis suggesting that fungi thought to have the most severe intrinsic constraints on recombinations actually may have the fewest.
A phylogenetic test of the Red Queen Hypothesis: Outcrossing and parasitism in the Nematode phylum
TLDR
It is found that selfing and asexuality are significantly less likely to arise on parasitic lineages than on free‐living ones, and this finding is consistent with the Red Queen Hypothesis.
Variable opportunities for outcrossing result in hotspots of novel genetic variation in a pathogen metapopulation
TLDR
It is found that the opportunities for outcrossing vary spatially, and populations supporting high levels of coinfection –a prerequisite of sex – result in hotspots of novel genetic diversity, thereby providing evidence of ecological and evolutionary benefits of outCrossing in pathogens.
Sexual selection in fungi
TLDR
It is proposed that sexual selection explains various fungal characteristics such as the observed high redundancy of pheromones at the B mating‐type locus of Agaricomycotina, the occurrence of multiple types of spores in Ascomycotina or the strong pherOMone signalling in yeasts.
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 148 REFERENCES
The Evolution of Sex: a Perspective from the Fungal Kingdom
TLDR
The state of the understanding of sex and its evolution in the fungal kingdom is reviewed and areas where the field has contributed and will continue to contribute to illuminating general principles and paradigms of sexual reproduction are reviewed.
Consequences of reproductive mode on genome evolution in fungi.
TLDR
The available data from fungi suggest that reproductive mode alters the rates and patterns of genome evolution in these organisms, e.g., protein evolution, mutation rate, codon usage, frequency of genome rearrangements and repetitive elements, and variation in chromosome size.
Yeast Sex: Surprisingly High Rates of Outcrossing between Asci
TLDR
The results highlight the potential for random mating between spores in natural strains, even in the presence of asci, and if this type of mating does occur in nature and it is between close relatives, then a great deal of mating behavior may be undetectable from genome sequences.
Why Sex Is Good: On Fungi and Beyond
TLDR
This chapter discusses aspects of fungal biology that are relevant for an understanding of the occurrence of sex in fungi and the main advantages of sexual reproduction compared to asexuality are likely to be acceleration of adaptive evolution and more efficient elimination of deleterious mutations.
Breeding systems and heterozygosity in populations of tetrad forming fungi
TLDR
The population genetic consequences of intratetrad selfing have not been worked out before and this note provides an introduction to the topic.
New Insights on Heterostyly: Comparative Biology, Ecology and Genetics
TLDR
Although the patterns of inheritance of the style morphs are well established in diverse taxa, the identity, number and organization of genes controlling the heterostylous syndrome are unknown, despite recent progress.
THE EVOLUTION OF ASEXUAL FUNGI: Reproduction, Speciation and Classification.
TLDR
These studies show that asexual or sexual reproductive morphology does not necessarily correlate with clonal or recombining reproductive behavior, and that fungi with all types of reproductive morphologies and behaviors can be accommodated by a phylogenetic species concept.
Rapid diversification of mating systems in ciliates
TLDR
There have been many transitions in the number of mating types, and the requirement of nuclear reorganization may be a more important factor than genetic exchange in determining the optimum number of mate types in a species.
Having sex, yes, but with whom? Inferences from fungi on the evolution of anisogamy and mating types
TLDR
It is argued that fungi represent highly suitable models to help resolve issues related to the evolution of distinct gamete classes, because the number of mating types vary from zero to thousands across taxa, anisogamy is present or not, and because there are frequent transitions between these conditions.
Mating System of the Anther Smut Fungus Microbotryum violaceum: Selfing under Heterothallism
TLDR
The origin of sex chromosomes is believed to have involved suppression of recombination around the essential sex determining genes on an ancestral autosomal pair and progressive expansion of this region of suppressed recombination through the recruitment of other sex-related factors.
...
1
2
3
4
5
...