Publications by authors named "Shelby J Priest"

Fungal sexual reproduction is controlled by the mating-type () locus. In contrast to a majority of species in the phylum Basidiomycota that have tetrapolar mating-type systems, the opportunistic human pathogen employs a bipolar mating-type system, with two mating types ( and α) determined by a single locus that is unusually large (~120 kb) and contains more than 20 genes. While several genes are associated with mating and sexual development, others control conserved cellular processes (e.

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Article Synopsis
  • * Researchers identified clinical isolates with hypermutation due to transposition of a retrotransposon (Cnl1), driven by a mutation in an RNA interference (RNAi) component.
  • * A study revealed that while some isolates lose RNAi function without triggering hypermutation, introducing RNAi loss mutations into non-hypermutator strains could induce a hypermutator phenotype, highlighting two possible evolutionary pathways following RNAi loss: either leading to hypermutation or enabling survival without it.
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While increased mutation rates typically have negative consequences in multicellular organisms, hypermutation can be advantageous for microbes adapting to the environment. Previously, we identified two hypermutator clinical isolates that rapidly develop drug resistance due to transposition of a retrotransposon, Cnl1. Cnl1-mediated hypermutation is caused by a nonsense mutation in the gene encoding a novel RNAi component, Znf3, combined with a tremendous transposon burden.

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Cryptococcus neoformans infections cause approximately 15% of AIDS-related deaths owing to a combination of limited antifungal therapies and drug resistance. A collection of clinical and environmental C. neoformans isolates were assayed for increased mutation rates via fluctuation analysis, and we identified two hypermutator C.

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Evaluating the quality of a de novo annotation of a complex fungal genome based on RNA-seq data remains a challenge. In this study, we sequentially optimized a Cufflinks-CodingQuary-based bioinformatics pipeline fed with RNA-seq data using the manually annotated model pathogenic yeasts Cryptococcus neoformans and Cryptococcus deneoformans as test cases. Our results show that the quality of the annotation is sensitive to the quantity of RNA-seq data used and that the best quality is obtained with 5-10 million reads per RNA-seq replicate.

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Hybridization has resulted in the origin and variation in extant species, and hybrids continue to arise despite pre- and post-zygotic barriers that limit their formation and evolutionary success. One important system that maintains species boundaries in prokaryotes and eukaryotes is the mismatch repair pathway, which blocks recombination between divergent DNA sequences. Previous studies illuminated the role of the mismatch repair component Msh2 in blocking genetic recombination between divergent DNA during meiosis.

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Diversity within the fungal kingdom is evident from the wide range of morphologies fungi display as well as the various ecological roles and industrial purposes they serve. Technological advances, particularly in long-read sequencing, coupled with the increasing efficiency and decreasing costs across sequencing platforms have enabled robust characterization of fungal genomes. These sequencing efforts continue to reveal the rampant diversity in fungi at the genome level.

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species utilize a variety of sexual reproduction mechanisms, which generate genetic diversity, purge deleterious mutations, and contribute to their ability to occupy myriad environmental niches and exhibit a range of pathogenic potential. The bisexual and unisexual cycles of pathogenic species are stimulated by properties associated with their environmental niches and proceed through well-characterized signaling pathways and corresponding morphological changes. Genes governing mating are encoded by the mating-type () loci and influence pathogenesis, population dynamics, and lineage divergence in .

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Sexual reproduction is vastly diverse and yet highly conserved across the eukaryotic domain. This ubiquity suggests that the last eukaryotic common ancestor (LECA) was sexual. It is hypothesized that several critical processes in sexual reproduction, including cell fusion and meiosis, were acquired during the evolution from the first eukaryotic common ancestor (FECA) to the sexual LECA.

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The Cryptococcus pathogenic species complex is a group of opportunistic human fungal pathogens that cause cryptococcal meningoencephalitis, an infection associated with unacceptably high mortality rates. The public health relevance of these pathogens has galvanized extensive research over the past several decades and led to characterization of their sexual cycles. This research has allowed several Cryptococcus species to develop into model fungal organisms for both pathogenesis and basic science studies.

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Candida species cause a variety of mucosal and invasive infections and are, collectively, the most important human fungal pathogens in the developed world. The majority of these infections result from a few related species within the "CUG clade," so named because they use a nonstandard translation for that codon. Some members of the CUG clade, such as Candida albicans, present significant clinical problems, whereas others, such as Candida (Meyerozyma) guilliermondii, are uncommon in patients.

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