P. Markus Wilken, Frances A. Lane, Emma T. Steenkamp, Michael J. Wingfield, Brenda D. Wingfield
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引用次数: 0
Abstract
Unidirectional mating-type switching is a form of homothallic reproduction known only in a small number of filamentous ascomycetes. Their ascospores can give rise to either self-sterile isolates that require compatible partners for subsequent sexual reproduction, or self-fertile individuals capable of completing this process in isolation. The limited studies previously conducted in these fungi suggest that the differences in mating specificity are determined by the architecture of the MAT1 locus. In self-fertile isolates that have not undergone unidirectional mating-type switching, the locus contains both MAT1-1 and MAT1-2 mating-type genes, typical of primary homothallism. In the self-sterile isolates produced after a switching event, the MAT1-2 genes are lacking from the locus, likely due to a recombination-mediated deletion of the MAT1-2 gene information. To determine whether these arrangements of the MAT1 locus support unidirectional mating-type switching in the Ceratocystidaceae, the largest known fungal assemblage capable of this reproduction strategy, a combination of genetic and genomic approaches were used. The MAT1 locus was annotated in representative species of Ceratocystis, Endoconidiophora, and Davidsoniella. In all cases, MAT1-2 genes interrupted the MAT1-1–1 gene in self-fertile isolates. The MAT1-2 genes were flanked by two copies of a direct repeat that accurately predicted the boundaries of the deletion event that would yield the MAT1 locus of self-sterile isolates. Although the relative position of the MAT1-2 gene region differed among species, it always disrupted the MAT1-1–1 gene and/or its expression in the self-fertile MAT1 locus. Following switching, this gene and/or its expression was restored in the self-sterile arrangement of the locus. This mirrors what has been reported in other species capable of unidirectional mating-type switching, providing the strongest support for a conserved MAT1 locus structure that is associated with this process. This study contributes to our understanding of the evolution of unidirectional mating-type switching.
期刊介绍:
Fungal Genetics and Biology, formerly known as Experimental Mycology, publishes experimental investigations of fungi and their traditional allies that relate structure and function to growth, reproduction, morphogenesis, and differentiation. This journal especially welcomes studies of gene organization and expression and of developmental processes at the cellular, subcellular, and molecular levels. The journal also includes suitable experimental inquiries into fungal cytology, biochemistry, physiology, genetics, and phylogeny.
Fungal Genetics and Biology publishes basic research conducted by mycologists, cell biologists, biochemists, geneticists, and molecular biologists.
Research Areas include:
• Biochemistry
• Cytology
• Developmental biology
• Evolutionary biology
• Genetics
• Molecular biology
• Phylogeny
• Physiology.