Mating Type in Filamentous Fungi

Abstract

Mating type genes regulate sexual compatibility and sexual reproduction in fungi. This review focuses on recent molecular analyses of well-characterized mating systems from representative ascomycete (Neurospora crassa, Podospora anserina) and basidiomycete (Ustilago maydis, Coprinus cinereus, Schizophyllum commune) fungi. These mating systems include many conserved components, such as gene regulatory polypeptides and pheromone/receptor signal transduction cascades, as well as conserved processes, like self-nonself recognition and controlled nuclear migration. The components' structures and their genetic arrangements in the mating system vary greatly in different fungi. Although similar components and processes are also found in ascomycete yeasts (Saccharomyces cerevisiae and Schizosaccharomyces pombe), the filamentous systems exhibit properties not encountered in yeast. Mating type genes act within, and control the development of, spatially differentiated fruiting bodies. The complex mating systems of basidiomycetes, unlike ascomycete systems, involve novel one-to-many specificity in both pheromone-receptor and homeodomain protein interactions.

Signaling via cAMP in fungi: interconnections with mitogen-activated protein kinase pathways

“…A hallmark of U. maydis infection of corn is the induction of large plant tumors filled with spores of the fungus. Sexual development in U. maydis is controlled by two loci, a and b [reviewed by Kronstad and Staben (1997)]. The a locus contains genes that encode pheromones and pheromone receptors that mediate recognition leading to the fusion of mating partners.…”

Increased heterozygosity for MHC class II lineages in newborn males

“…The best-known examples are the self-incompatibility system of plants, fungal mating types and histocompatibility systems of marine invertebrates. [1][2][3][4][5][6] In vertebrate animals, no such system is known but there is some evidence that the major histocompatibility complex (MHC) may be acting as a genetic compatibility system. [6][7][8][9][10][11] The MHC is primarily involved in immunological functions…”

Dissecting Defense-Related and Developmental Transcriptional Responses of Maize during Ustilago maydis Infection and Subsequent Tumor Formation

“…Subsequent fungal differentiation is intimately coupled to growth within host tissue and includes extensive branching, karyogamy, hyphal fragmentation, and teliospore formation (Banuett and Herskowitz, 1996;Kahmann et al, 2000). The sexual life cycle of U. maydis is governed by a tetrapolar mating system consisting of the a and b mating type loci (Kronstad and Staben, 1997;Kahmann et al, 2000). The biallelic a locus encodes a pheromone/ receptor system required for sporidial fusion (Bölker et al, 1992;Spellig et al, 1994).…”