TRANSITIONS FROM REPRODUCTIVE SYSTEMS GOVERNED BY TWO SELF-INCOMPATIBLE LOCI TO ONE IN FUNGI
Article first published online: 27 SEP 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 67, Issue 2, pages 501–516, February 2013
How to Cite
Vuilleumier, S., Alcala, N. and Niculita-Hirzel, H. (2013), TRANSITIONS FROM REPRODUCTIVE SYSTEMS GOVERNED BY TWO SELF-INCOMPATIBLE LOCI TO ONE IN FUNGI. Evolution, 67: 501–516. doi: 10.1111/j.1558-5646.2012.01783.x
- Issue published online: 28 JAN 2013
- Article first published online: 27 SEP 2012
- Accepted manuscript online: 24 AUG 2012 03:16AM EST
- Received April 2, 2012 Accepted August 3, 2012
- bifactorial (tetrapolar) system;
- frequency-dependent selection;
- mating-type loci;
- unifactorial (bipolar) system
Self-incompatibility (SI), a reproductive system broadly present in plants, chordates, fungi, and protists, might be controlled by one or several multiallelic loci. How a transition in the number of SI loci can occur and the consequences of such events for the population's genetics and dynamics have not been studied theoretically. Here, we provide analytical descriptions of two transition mechanisms: linkage of the two SI loci (scenario 1) and the loss of function of one incompatibility gene within a mating type of a population with two SI loci (scenario 2). We show that invasion of populations by the new mating type form depends on whether the fitness of the new type is lowered, and on the allelic diversity of the SI loci and the recombination between the two SI loci in the starting population. Moreover, under scenario 1, it also depends on the frequency of the SI alleles that became linked. We demonstrate that, following invasion, complete transitions in the reproductive system occurs under scenario 2 and is predicted only for small populations under scenario 1. Interestingly, such events are associated with a drastic reduction in mating type number.