Summary
An evaluation of the structure of incompatibility systems in the higher fungi and its effect on inbreeding and outbreeding indicates that: In unifactorial systems a one-locus structure, which permits 50 per cent, inbreeding, is preferable to a two-locus structure, which would permit inbreeding to rise above 50 per cent. In bifactorial systems a two-locus structure for each factor is advantageous because it makes possible a high outbreeding potential with a small number of alleles. The two-locus structure also confers flexibility on the inbreeding potential. A symmetrical distribution of alleles among the four loci of a two-locus bifactorial system allows for maximal outbreeding. The advantage of symmetry is most pronounced when the total number of allelic specificities is not large. The asymmetrical distribution of alleles among the four incompatibility loci of Schizophyllum commune suggests that its incompatibility system evolved from a one-locus unifactorial system. The Aß locus, with 32 alleles, is assumed to be the oldest locus; the remaining three loci, with 9 alleles each, are assumed to have come into operation within a short time of each other, at a later stage.
Similar content being viewed by others
Article PDF
References
Burnett, J H. 1965. The natural history of recombination systems. In Incompatibility in Fungi (K. Esser and J. R. Raper, eds.), pp. 98–113. Springer-Verlag, New York.
Day, P R. 1960. The structure of the A mating-type locus in Coprinus lagopus. Genetics, 45, 641–651.
Day, P R. 1963. The structure of the A mating-type factor in Coprinus lagopus: wild alleles. Genet Res, Camb, 4, 323–325.
Dobzhansky, T, and Wright, S. 1941. Genetics of natural populations. V. Relations between mutation rates and accumulation of lethals in populations of Drosophila pseudo-obscura. Genetics, 26, 23–52.
Flexer, A S. 1963. Bipolar incompatibility in Polyporus palustris. Thesis, Harvard Univ., Cambridge, Mass.
Flexer, A S. 1965. Bipolar incompatibility in Polyporus palustris. (Abstr.) Amer Jour Bot, 52, 634.
Fries, N, and Jonasson, L. 1941. Über die Interfertilität verschiedener Stamme von Polyporus abietinus. Svensk Bot Tidskr, 35, 177–193.
Koltin, Y, Raper, J R, and Simchen, G. 1967. The genetic structure of the incompatibility factors of Schizophyllum commune: The B factor. Proc Natl Acad Sci, US, 57, 55–62.
Mather, K. 1942. Heterothally as an outbreeding mechanism in fungi. Nature, 149, 54–56.
Neuhauser, K S, and Gilbertson, R L. 1971. Some aspects of bipolar heterothallism in Fomes cajanderi. Mycologia, 63, 722–735.
Papazian, H P. 1951. The incompatibility factors and a related gene in Schizophyllum commune. Genetics, 36, 441–459.
Parag, Y, and Koltin, Y. 1971. The structure of the incompatibility factors of Schizophyllum commune: Constitution of the three classes of B factors. Molec Gen Genetics, 112, 43–48.
Prévost, G. 1962. Étude génétique d'un Basidiomycète: Coprinus radiatus. Thesis, Univ. de Paris, Paris.
Raper, J R. 1966. Genetics of Sexuality in Higher Fungi. Ronald Press, New York. viii + 283 pp.
Raper, J R, Baxter, M G, and Ellingboe, A H. 1960. The genetic structure of the incompatibility factors of Schizophyllum commune: The A-factor. Proc Natl Acad Sci, US, 46, 833–842.
Raper, J R, Baxter, M G, and Middleton, R B. 1958. The genetic structure of the incompatibility factors in Schizophyllum commune. Proc Natl Acad Sci, US, 44, 889–900.
Raper, J R, Krongelb, G S, and Baxter, M G. 1958. The number and distribution of incompatibility factors in Schizophyllum commune. Amer Nat, 92, 221–232.
Schaap, T, and Simchen, G. 1971. Genetic control of recombination affecting mating factors in a population of Schizophyllum, and its relation to inbreeding. Genetics, 68, 67–75.
Simchen, G. 1967. Genetic control of recombination and the incompatibility system in Schizophyllum commune. Genet Res, Camb, 9, 195–210.
Stamberg, J. 1968. Two independent gene systems controlling recombination in Schizophyllum commune. Molec Gen Genetics, 102, 221–228.
Stamberg, J. 1969. Genetic control of recombination in Schizophyllum commune: The occurrence and significance of natural variation. Heredity, 24, 361–368.
Stamberg, J, and Simchen, G. 1970. Specific effects of temperature on recombination in Schizophyllum commune. Heredity, 25, 41–52.
Takemaru, T. 1961. Genetic studies on fungi. X. The mating system in Hymenomycetes and its genetical mechanism. Biol Jour Okayama Univ, 7, 133–211.
Terakawa, H. 1960. The incompatibility factors in Pleurotus ostreatus. Scientific papers of the College of Gen Education, Univ. Tokyo, 10, 65–71.
Whitehouse, H L K. 1949. Heterothallism and sex in fungi. Biol Rev, 24, 411–447.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Stamberg, J., Koltin, Y. The organisation of the incompatibility factors in higher fungi: The effect of structure and symmetry on breeding. Heredity 30, 15–26 (1973). https://doi.org/10.1038/hdy.1973.2
Received:
Issue Date:
DOI: https://doi.org/10.1038/hdy.1973.2
This article is cited by
-
Evolution of uni- and bifactorial sexual compatibility systems in fungi
Heredity (2013)
-
The breeding biology of biotypes of the witches' broom pathogen of cocoa, Crinipellis perniciosa
Heredity (1994)
-
Only one of the paired Schizophyllum commune Aα mating-type, putative homeobox genes encodes a homeodomain essential for Aα-regulated development
Molecular and General Genetics MGG (1994)