RNA silencing can function as a virus defense mechanism in diverse range of eukaryotes, and many viruses are capable suppressing the machinery targeting them. However, extent to which this occurs between fungal mycoviruses is unclear. Here, three Aspergillus dsRNA were partially characterized, their relationship was investigated. 1816 related Agaricus bisporus white button mushroom 1 suppresses through that alters level small interfering RNA. 178 L1 Gremmeniella abietina does not appear...

Mycotoxins are natural fungal products that defined by their harmful effects on humans and animals. Aflatoxin contamination of maize Aspergillus species trichothecene small grains Fusarium two the most severe mycotoxin problems in United States. We investigating RNA silencing an effort to identify novel ways control crops. Transformation Aspergilli (A. flavus A. parasiticus) a (F. graminearum) with inverted repeat transgenes (IRT) containing sequences mycotoxin-specific regulatory genes...

Meiotic drive is a non-Mendelian inheritance phenomenon in which certain selfish genetic elements skew sexual transmission their own favor. In some cases, progeny or gametes carrying meiotic element can survive preferentially because it causes the death malfunctioning of those that do not carry it. Neurospora, be observed fungal spore killing. cross Spore killer (Sk) × WT (Sk-sensitive), ascospores containing allele survive, whereas ones with sensitive degenerate. Sk-2 and Sk-3 are most...

The versatility of RNA-dependent RNA polymerases (RDRPs) in eukaryotic gene silencing is perhaps best illustrated the kingdom Fungi. Biochemical and genetic studies Schizosaccharomyces pombe Neurospora crassa show that these types enzymes are involved a number fundamental gene-silencing processes, including heterochromatin regulation S. meiotic N. crassa. Here we Aspergillus nidulans, another model fungus, does not require an RDRP for inverted repeat transgene (IRT)-induced silencing....

Meiotic drive is widespread in nature. The conflict it generates expected to be an important motor for evolutionary change and innovation. In this study, we investigated the genomic consequences of two large multi-gene meiotic elements, Sk-2 Sk-3, found filamentous ascomycete Neurospora intermedia. Using long-read sequencing, generated first complete well-annotated genome assemblies large, highly diverged, non-recombining regions associated with elements. Phylogenetic analysis shows that,...

Significance In order to survive, most organisms must deal with parasites. Such parasites can be other or, sometimes, selfish genes found within the host genome itself. While much is known about parasitic organisms, interaction their hosts, and ability spread between species, less genes. We here identify a “spore killer” gene in fungus Neurospora sitophila . The appears have evolved genus but has entered species through hybridization introgression. also show that counteract RNA interference....

SUMMARY An RNA silencing construct was used to alter mycotoxin production in the plant pathogenic fungus Fusarium culmorum , incitant of crown and foot rot on wheat. The transformation a wild‐type strain its nitrate reductase‐deficient mutant with inverted repeat transgenes (IRTs) containing sequences corresponding trichothecene regulatory gene TRI6 achieved using hygromycin B resistance as selectable marker. Southern analysis revealed variety integration patterns IRT. One transformant...

In Neurospora crassa, genes lacking a pairing partner during meiosis are suppressed by process known as meiotic silencing unpaired DNA (MSUD). To identify novel MSUD components, we have developed high-throughput reverse-genetic screen for use with the N. crassa knockout library. Here describe screening method and characterization of gene (sad-3) subsequently discovered. SAD-3 is putative helicase required sexual spore production. It exists in complex other proteins perinuclear region, center...

Abstract Meiotic silencing by unpaired DNA (MSUD) is a process that detects regions between homologous chromosomes and silences them for the duration of sexual development. While phenomenon MSUD well recognized, poorly understood. In this report, we provide two lines evidence linking detection to physical search homology. First, have found putative SNF2-family protein (SAD-6) required efficient in Neurospora crassa. SAD-6 closely related Rad54, known facilitate key steps repair double-strand...

ABSTRACT While the transport of sediment by unidirectional currents or oscillatory (wave‐induced) has been investigated, very little attention paid to problem threshold under two mechanisms combined. Studies were carried out using cohesionless sand‐sized (mean diameters: 142, 363, 771 and 1134 μm) quartz grains in a flume, within which an carriage had installed. The experiments velocities ranging between 0 27 cm s ‐1 , combined with simulated wave‐induced (at periods 5 15 s) from 35 . was...

Abstract RNA interference (RNAi) depends on the production of small to regulate gene expression in eukaryotes. Two RNAi systems exist control repetitive selfish elements Neurospora crassa. Quelling targets transgenes during vegetative growth, whereas meiotic silencing by unpaired DNA (MSUD) silences genes meiosis. The two mechanisms require common proteins, such as RNA-directed polymerases, Dicers, and Argonaute slicers. We have previously demonstrated that, while redundant dicer activity...

Abstract In Neurospora crassa, unpaired genes are silenced by a mechanism called meiotic silencing DNA (MSUD). Although some RNA interference proteins necessary for this process, its requirement of small RNAs has yet to be formally established. Here we report the characterization targeting an region, using Illumina sequencing.

Abstract Neurospora fungi harbor a group of meiotic drive elements known as Spore killers (Sk). killer-2 (Sk-2) and killer-3 (Sk-3) are two Sk that map to region suppressed recombination. Although this recombination block is limited crosses between Sk-sensitive (SkS) strains, its existence has hindered characterization. Here we report the circumvention obstacle by combining classical genetic screen with next-generation sequencing technology three-point crossing assays. This approach allowed...

Abstract A Neurospora meiotic drive element known as Spore killer-2 (Sk-2) achieves biased transmission through sexual reproduction by killing siblings that inherit a competing allele... Sk-2 is was discovered in wild populations of fungi over 40 years ago. While early studies quickly determined transmits itself manner via spore killing, the genetic factors responsible for this phenomenon have remained mostly unknown. Here, we identify and characterize rfk-1, gene required Sk-2-based...

ABSTRACT The genus Aspergillus is ideally suited for the investigation of RNA silencing evolution because it includes species that have experienced a variety gene changes. Our work on this subject begins here with model nidulans . Filamentous ascomycete fungi generally each encode two core proteins, Dicer and Argonaute, but A. appears to lost one truncation events. Although role in growth, development, or was not detected truncated genes, they do produce spliced poly(A)-tailed transcripts,...

Abstract During meiosis in the filamentous fungus Neurospora crassa, unpaired genes are identified and silenced by a process known as meiotic silencing DNA (MSUD). Previous work has uncovered six proteins required for MSUD, all of which also essential progression. Additionally, they localize perinuclear region, suggesting that it is center MSUD activity. Nevertheless, at least subset must be present inside nucleus, recognition undoubtedly takes place there. In this study, we characterized...

Abstract Spore killers are meiotic drive elements that can block the development of sexual spores in fungi. In maize ear rot and mycotoxin-producing fungus Fusarium verticillioides, a spore killer called SkK has been mapped to 102-kb interval chromosome V. Here, we show gene within this interval, SKC1, is required for SkK-mediated killing drive. We also demonstrate SKC1 associated with at least 4 transcripts, 2 sense (sense-SKC1a sense-SKC1b) antisense (antisense-SKC1a antisense-SKC1b). Both...

Abstract In Neurospora, genes not paired during meiosis are targeted by meiotic silencing unpaired DNA (MSUD). Here, our bimolecular fluorescence complementation (BiFC) study suggests that RNA-directed RNA polymerase, Dicer, Argonaute, and others form a complex in the perinuclear region, with intimate interactions among majority of them. We have also shown SAD-2 is likely anchor for this assembly.

Significance Homologous chromosomes (or selected chromosomal regions) can engage in sequence-specific pairing as intact entities. The mechanism behind this process remains mysterious, part because prevailing evidence suggests that DNA molecules must be broken before being evaluated for homology. In work, we study a phenomenon detects dissimilar fragments present at the allelic positions on pair of homologous during meiosis. We find recognition such is incompatible with canonical...

Meiotic silencing by unpaired DNA (MSUD) is a biological process that searches pairs of homologous chromosomes (homologs) for segments are unpaired. Genes found within silenced the duration meiosis. In this report, we describe identification and characterization Neurospora crassa sad-7, gene encodes protein with an RNA recognition motif (RRM). Orthologs sad-7 in wide range ascomycete fungi. N. crassa, required fully efficient MSUD response to genes. Additionally, at least one parent must...

Fusarium verticillioides is an agriculturally important fungus because of its association with maize and propensity to contaminate grain toxic compounds. Some isolates the harbor a meiotic drive element known as Spore killer (Sk(K)) that causes nearly all surviving progeny from Sk(K) × killer-susceptible (Sk(S)) cross inherit allele. has been mapped chromosome V but genetic responsible for yet be identified. In this study, we used cleaved amplified polymorphic sequence markers genotype...