LINKAGE TO THE MATING-TYPE LOCUS ACROSS THE GENUS MICROBOTRYUM: INSIGHTS INTO NONRECOMBINING CHROMOSOMES
Article first published online: 26 JUN 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 66, Issue 11, pages 3519–3533, November 2012
How to Cite
Petit, E., Giraud, T., de Vienne, D. M., Coelho, M. A., Aguileta, G., Amselem, J., Kreplak, J., Poulain, J., Gavory, F., Wincker, P., Young, S. K., Cuomo, C., Perlin, M. H. and Hood, M. E. (2012), LINKAGE TO THE MATING-TYPE LOCUS ACROSS THE GENUS MICROBOTRYUM: INSIGHTS INTO NONRECOMBINING CHROMOSOMES. Evolution, 66: 3519–3533. doi: 10.1111/j.1558-5646.2012.01703.x
- Issue published online: 25 OCT 2012
- Article first published online: 26 JUN 2012
- Accepted manuscript online: 31 MAY 2012 12:05AM EST
- Received January 19, 2012 Accepted April 27, 2012
- Evolutionary strata;
- gene conversion;
- mating-type chromosome;
- sex chromosome
Parallels have been drawn between the evolution of nonrecombining regions in fungal mating-type chromosomes and animal and plant sex chromosomes, particularly regarding the stages of recombination cessation forming evolutionary strata of allelic divergence. Currently, evidence and explanations for recombination cessation in fungi are sparse, and the presence of evolutionary strata has been examined in a minimal number of fungal taxa. Here, the basidiomycete genus Microbotryum was used to determine the history of recombination cessation for loci on the mating-type chromosomes. Ancestry of linkage with mating type for 13 loci was assessed across 20 species by a phylogenetic method. No locus was found to exhibit trans-specific polymorphism for alternate alleles as old as the mating pheromone receptor, indicating that ages of linkage to mating type varied among the loci. The ordering of loci in the ancestry of linkage to mating type does not agree with their previously proposed assignments to evolutionary strata. This study suggests that processes capable of influencing divergence between alternate alleles may act at loci in the nonrecombining regions (e.g., gene conversion) and encourages further work to dissect the evolutionary processes acting upon genomic regions that determine mating compatibility.