Location: Crops Pathology and Genetics ResearchTitle: Sex-linked phenotypic divergence in the hermaphrodite fungus Neurospora tetrasperma Author
Submitted to: Proceedings of the Royal Society of London: Biological Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2013
Publication Date: 6/9/2013
Publication URL: http://rspb.royalsocietypublishing.org/search?fulltext=kasuga&submit=yes&andorexactfulltext=and&x=0&y=0
Citation: Samils, N., Gioti, A., Karlsson, M., Yu, S., Kasuga, T., Bastiaans, E., Wang, Z., Li, N., Townsend, J., Johannesson, H. 2013. Sex-linked phenotypic divergence in the hermaphrodite fungus Neurospora tetrasperma. Proceedings of the Royal Society of London: Biological Sciences. doi:10.1098/rspb.2013.0862. Interpretive Summary: Plant-associated microbes such as fungi and oomycete may require two compatible partners (analogous to male and female) or may not require partners (selfing) to reproduce sexually. Genetic mechanisms and ecological implications of the reproductive modes are unclear. We investigated the genome of a selfing ascomycetous fungus Neurospora tetrasperma, and identified numbers of genes located on sex chromosomes which were differentially expressed during mating.
Technical Abstract: Here we present a study of the molecular phenotype linked to a large region of suppressed recombination (extending over ~ 7 Mbp and >1,500 genes) surrounding the mating-type (mat) locus of the filamentous ascomycete Neurospora tetrasperma. While the remainder of the genome is largely homoallelic, this region of recombinational suppression has enabled sequence divergence to accumulate between the two mat chromosomes. To ascertain the functional correlates of this divergent region, we assayed divergence in gene expression linked to N. tetrasperma mating type using DNA microarrays. Culturing N. tetrasperma on agar media that induce sexual or vegetative growth, we found 196 genes significantly differentially expressed between mat A and mat a mating types. Our data show that the genes exhibiting mat-linked expression are enriched in the region genetically linked to mating type, and sequence and expression divergence are positively correlated. This discovery of differentially expressed genes associated with mating type provides a link between genotypic and phenotypic divergence in this taxon, and illustrates an analogue to sexual dimorphism found in the fungal kingdom.