Chapter 32 : Why Sex Is Good: On Fungi and Beyond

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Weismann argued that the increased genetic variation among the offspring would allow more efficient natural selection and in this way accelerate evolution. A general conclusion emerging from the theory is that a prerequisite for the validity of explanations for sex, i.e., that increased genetic variation among offspring favors both natural selection and elimination of deleterious mutations, is that the genetic variation for fitness in the population is lower than would result from a random distribution of the relevant alleles. In a similar way, sex may be maintained in different groups of organisms for reasons that differ between these groups and also from the reasons that have led to its evolution. This chapter discusses aspects of fungal biology that are relevant for an understanding of the occurrence of sex in fungi. The main advantages of sexual reproduction compared to asexuality are likely to be acceleration of adaptive evolution and more efficient elimination of deleterious mutations, while major disadvantages are the costs in terms of time and energy expenditure and of the production of male structures. Strikingly, in many fungi sex occurs at the end of the growing season, when the conditions for somatic growth become adverse, and furthermore, sex is often linked to the formation of specialized survival structures. Another possible example of a link between sex and an essential process, discussed in this chapter, is the presence of an efficient selection arena in the sexual, but not in the asexual, cycle.

Citation: Aanen D, Hoekstra R. 2007. Why Sex Is Good: On Fungi and Beyond, p 527-534. In Heitman J, Kronstad J, Taylor J, Casselton L (ed), Sex in Fungi. ASM Press, Washington, DC. doi: 10.1128/9781555815837.ch32
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Figure 32.1

(a) The heterothallic life cycle of a mushroom-forming basidiomycete. (b) The monokaryons exhibit two clearly distinct behaviors in mating: accepting a nucleus and donating a nucleus, which can be considered female and male roles, respectively. (c) An asexual (or [secondarily] homothallic) mutant that still can donate a nucleus has a 1.5-fold advantage, because it doubles its fitness via the female route while maintaining its fitness via the male route. The percentages indicate the representation of the hypothetical asexuality allele in the spores resulting from the female route (100%) and the male route (50%).

Citation: Aanen D, Hoekstra R. 2007. Why Sex Is Good: On Fungi and Beyond, p 527-534. In Heitman J, Kronstad J, Taylor J, Casselton L (ed), Sex in Fungi. ASM Press, Washington, DC. doi: 10.1128/9781555815837.ch32
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1. Aanen, D. K.,, T. W. Kuyper,, A. J. M. Debets, and, R. F. Hoekstra. 2004. The evolution of non-reciprocal nuclear exchange in mushrooms as a consequence of genomic conflict. Proc. R. Soc. London B 271: 12351241.
2. Agrawal, A. F. 2006. Evolution of sex: why do organisms shuffle their genotypes? Curr. Biol. 16: R696R704.
3. Ainsworth,, A. M., A. D. M. Rayner,, S. J. Broxholme, and, J. R. Beeching. 1990. Occurrence of unilateral genetic transfer and genomic replacement between strains of Stereum hirsutum from nonoutcrossing and outcrossing populations. New Phytol. 115: 119128.
4. Anagnostakis, S. L. 1988. Cryphonectria parasitica, cause of chestnut blight, p. 123–136. In D. S. Ingram,, P. H. Williams, and, G. S. Sidhu (ed.), Advances in Plant Pathology, vol. 6. Genetics of Plant Pathogenic Fungi. Academic Press, New York, NY.
5. Barton, N. H., and, B. Charlesworth. 1998. Why sex and recombination? Science 281: 19861990.
6. Bell, G. 1982. The Masterpiece of Nature: the Evolution and Genetics of Sexuality. CroomHelm, London, United Kingdom.
7. Birdsell, J., and, C. Wills. 1996. Significant competitive advantage conferred by meiosis and syngamy in the yeast Saccharomyces cerevisiae. Proc. Natl. Acad. Sci. USA 93: 908912.
8. Bruggeman, J.,, A. J. M. Debets, and, R. F. Hoekstra. 2004. Selection arena in Aspergillus nidulans. Fungal. Genet. Biol. 41: 181188.
9. Bruggeman, J.,, A. J. M. Debets,, P. J. Wijngaarden,, J. deVisser, and R. F. Hoekstra. 2003. Sex slows down the accumulation of deleterious mutations in the homothallic fungus Aspergillus nidulans. Genetics 164: 479485.
10. Buller, A. H. R. 1931. Researches on Fungi, vol. IV. Longmans, Green and Co., London, United Kingdom.
11. Burnett, J. 2003. Fungal populations and species. Oxford University Press, Oxford, England.
12. Burnett, J. H., and, M. E. Boulter. 1963. The mating systems of fungi. II. Mating systems of the Gasteromycetes Mycocalia denudata and M. duriaeana. New Phytol. 62: 217236.
13. Burt, A. 2000. Perspective: sex, recombination, and the efficacy of selection—was Weismann right? Evolution 54: 337351.
14. Casselton, L. A., and, A. Economou. 1985. Dikaryon formation, p. 213–229. In D. Moore,, L. A. Casselton,, D. A. Wood, and, J. C. Frankland (ed.), Developmental Biology of Higher Fungi. Cambridge University Press, Cambridge, England.
15. Castanho, B.,, E. E. Butler, and, R. J. Shepherd. 1978. Association of double-stranded-RNA with Rhizoctonia decline. Phytopathology 68: 15151519.
16. Chao, L.,, T. T. Tran, and, T. T. Tran. 1997. The advantage of sex in the RNA virus phi6. Genetics 147: 953959.
17. Charlesworth, B. 1980. The cost of sex in relation to mating system. J. Theor. Biol. 84: 655671.
18. Coenen,, A., F. Kevei, and, R. F. Hoekstra. 1997. Factors affecting the spread of double-stranded RNA viruses in Aspergillus nidulans. Genet. Res. 69: 110.
19. Day, P. R., and, J. A. Dodds. 1979. Viruses of plant pathogenic fungi, p. 201–238. In P. A. Lemke (ed.), Viruses and Plasmids in Fungi. Marcel Dekker, New York, NY.
20. de Visser,, J. A. G. M., and S. F. Elena. 2007. The evolution of sex: empirical insights into the roles of epistasis and drift. Nat. Rev. Genet. 8: 139149.
21. de Visser, J. A. G. M.,, R. F. Hoekstra, and, H. vandenEnde. 1997. Test of interaction between genetic markers that affect fitness in Aspergillus niger. Evolution 51: 14991505.
22. Elena, S. F., and, R. E. Lenski. 1997. Test of synergistic interactions among deleterious mutations in bacteria. Nature 390: 395398.
23. Elliott, C. G. 1994. Reproduction in Fungi: Genetical and Physiological Aspects. Chapman & Hall, London, England.
24. Goddard, M. R.,, H. Charles,, J. Godfray, and, A. Burt. 2005. Sex increases the efficacy of natural selection in experimental yeast populations. Nature 434: 636640.
25. Griffiths, A. J. F. 1992. Fungal senescence. Annu. Rev. Genet. 26: 351372.
26. Hoekstra,, R. F., and E. N. Vanloo. 1986. The cost of sex in hermaphrodite populations with variation in functional sex. J. Theor. Biol. 122: 441452.
27. Ihrmark, K.,, H. Johannesson,, E. Strenstrom, and, J. Stenlid. 2002. Transmission of double-stranded RNA in Heterobasidion annosum. Fungal. Genet. Biol. 36: 147154.
28. Ihrmark, K.,, E. Stenstrom, and, J. Stenlid. 2004. Double-stranded RNA transmission through basidiospores of Heterobasidion annosum. Mycol. Res. 108: 149153.
29. Kondrashov, A. S. 1993. Classification of hypotheses on the advantage of amphimixis. J. Hered. 84: 372387.
30. Kühner,, R. 1977. Variation of nuclear behavior in Homobasidiomycetes. Trans. Br. Mycol. Soc. 68: 116.
31. Lamoure, D. 1989. Indexes of useful informations for intercompatibility tests in Basidiomycetes V-Agaricales sensu-lato. Cryptogam. Mycol. 10: 4180.
32. Lewis,, W. M. 1983. Interruption of synthesis as a cost of sex in small organisms. Am. Nat. 121: 825834.
33. Maynard Smith, J. 1978. The Evolution of Sex. Cambridge University Press, Cambridge, England.
34. Maynard Smith, J. 1971. What use is sex? J. Theor. Biol. 30: 319335.
35. Michod,, R., and B. R. Levin (ed.). 1987. The Evolution of Sex: a Critical Review of Current Ideas. Sinauer Associates, Sunderland, MA.
36. Muller, H. J. 1964. The relation of recombination to mutational advance. Mutat. Res. 1: 29.
37. Otto,, S. P., and T. Lenormand. 2002. Resolving the paradox of sex and recombination. Nat. Rev. Genet. 3: 252261.
38. Petersen, R. H. 1995. There’s more to a mushroom than meets the eye—mating studies in the Agaricales. Mycologia 87: 117.
39. Quintanilha,, A. 1937. Contribution à l’étude génétique du phénomène de Buller. C. R. Acad. Sci. Paris 205: 747.
40. Rizet, G. 1953. Sur l’impossibilite d’obtenir la multiplication vegetative ininterrompue et illimitee de l’ascomycete Podospora anserina. C. R. Hebd. Seances Acad. Sci. 237: 838840.
41. Rogers,, H. J., K. W. Buck, and, C. M. Brasier. 1986. Transmission of double-stranded-RNA and a disease factor in Ophiostoma ulmi. Plant Pathol. 35: 277287.
42. Rogers, H. J.,, K. W. Buck, and, C. M. Brasier. 1988. dsRNA and disease factors of the aggressive subgroup of Ophiostoma ulmi. Dekker, New York, NY.
43. Romaine, C. P.,, P. Ulhrich, and, B. Schlagnhaufer. 1993. Transmission of La France isometric virus during basidiosporogenesis in Agaricus bisporus. Mycologia 85: 175179.
44. Sanjuan, R.,, A. Moya, and, S. F. Elena. 2004. The contribution of epistasis to the architecture of fitness in an RNA virus. Proc. Natl. Acad. Sci. USA 101: 1537615379.
45. Silliker, M. E.,, M. R. Liotta, and, D. J. Cummings. 1996. Elimination of mitochondrial mutations by sexual reproduction: two Podospora anserina mitochondrial mutants yield only wild-type progeny when mated. Curr. Genet. 30: 318324.
46. Stearns, S. C. (ed.). 1987. The Evolution of Sex and Its Consequences. Birkhauser Verlag, Basel, Switzerland.
47. van der Gaag, M.,, A. J. M. Debets,, J. Oosterhof,, M. Slakhorst,, J. Thijssen, and, R. F. Hoekstra. 2000. Sporekilling meiotic drive factors in a natural population of the fungus Podospora anserina. Genetics 156: 593605.
48. Weismann, A. 1886. Zur Frage nach der Vererbung erworbener Eigenschaften. Biol. Zentbl. 6: 3348.
49. Weismann,, A. 1904. The Evolution Theory. Edward Arnold, London, United Kingdom.
50. West, S. A.,, C. M. Lively, and, A. F. Read. 1999. A pluralist approach to sex and recombination. J. Evol. Biol. 12: 10031012.
51. Zeyl, C., and, G. Bell. 1997. The advantage of sex in evolving yeast populations. Nature 388: 465468.

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