Filamentous fungi are of great importance in ecology, agriculture, medicine, and biotechnology. Thus, it is not surprising that genomes for more than 100 filamentous fungi have been sequenced, most of them by Sanger sequencing. While next-generation sequencing techniques have revolutionized genome resequencing, e.g. for strain comparisons, genetic mapping, or transcriptome and ChIP analyses, de novo assembly of eukaryotic genomes still presents significant hurdles, because of their large size and stretches of repetitive sequences. Filamentous fungi contain few repetitive regions in their 30–90 Mb genomes and thus are suitable candidates to test de novo genome assembly from short sequence reads. Here, we present a high-quality draft sequence of the Sordaria macrospora genome that was obtained by a combination of Illumina/Solexa and Roche/454 sequencing. Paired-end Solexa sequencing of genomic DNA to 85-fold coverage and an additional 10-fold coverage by single-end 454 sequencing resulted in ∼4 Gb of DNA sequence. Reads were assembled to a 40 Mb draft version (N50 of 117 kb) with the Velvet assembler. Comparative analysis with Neurospora genomes increased the N50 to 498 kb. The S. macrospora genome contains even fewer repeat regions than its closest sequenced relative, Neurospora crassa. Comparison with genomes of other fungi showed that S. macrospora, a model organism for morphogenesis and meiosis, harbors duplications of several genes involved in self/nonself-recognition. Furthermore, S. macrospora contains more polyketide biosynthesis genes than N. crassa. Phylogenetic analyses suggest that some of these genes may have been acquired by horizontal gene transfer from a distantly related ascomycete group. Our study shows that, for typical filamentous fungi, de novo assembly of genomes from short sequence reads alone is feasible, that a mixture of Solexa and 454 sequencing substantially improves the assembly, and that the resulting data can be used for comparative studies to address basic questions of fungal biology.

The antifungal protein PAF from Penicillium chrysogenum exhibits growth-inhibitory activity against a broad range of filamentous fungi. Evidence from this study suggests that disruption of Ca 2؉ signaling/homeostasis plays an important role in the mechanistic basis of PAF as a growth inhibitor. Supplementation of the growth medium with high Ca 2؉ concentrations counteracted PAF toxicity toward PAF-sensitive molds. By using a transgenic Neurospora crassa strain expressing codon-optimized aequorin, PAF was found to cause a significant increase in the resting level of cytosolic free Ca 2؉ ( The secreted antifungal protein PAF from Penicillium chrysogenum is a small-molecular-mass (6.2 kDa), cationic, and cysteine-rich peptide that inhibits the growth of numerous filamentous fungi (14)(15)(16)21). It belongs to a family of antifungal peptides which show-despite considerable amino acid homology-significant differences in species specificity and modes of action (reviewed in reference 27). Importantly, the primary structures of these antifungals show no similarity to those from higher eukaryotes, e.g., plants, insects, or mammals (see reference 28 for a detailed review on parallels with and differences between PAF and antimicrobial proteins from higher eukaryotes and their mechanisms of action). Apart from the Aspergillus giganteus-derived antifungal protein AFP (19, 45; reviewed in reference 29), PAF is one of the best-studied peptides of this protein family. We have shown that PAF causes rapid hyperpolarization of the plasma membrane at hyphal tips, increased K ϩ efflux, induction of oxidative stress, and apoptotic cell death (21,25) and that PAF is internalized by hyphae of PAF-sensitive fungi (33). Furthermore, we have shown that PAF interferes with at least two signaling cascades, the protein kinase C/mitogen-activated protein (MAP) kinase and the cyclic AMP (cAMP

SummaryMsDef1 and MtDef4 from Medicago spp. are small cysteine-rich defensins with potent antifungal activity against a broad range of filamentous fungi. Each defensin has a hallmark γ-core motif (GXCX3-9C), which contains major determinants of its antifungal activity. In this study, the antifungal activities of MsDef1, MtDef4, and peptides derived from their γ-core motifs, were characterized during colony initiation in the fungal model, Neurospora crassa. These defensins and their cognate peptides inhibited conidial germination and accompanying cell fusion with different potencies. The inhibitory effects of MsDef1 were strongly mediated by the plasma membrane localized sphingolipid glucosylceramide. Cell fusion was selectively inhibited by the hexapeptide RGFRRR derived from the γ-core motif of MtDef4. Fluorescent labelling of this hexapeptide showed that it strongly bound to the germ tube plasma membrane/cell wall. Using N. crassa expressing the Ca 2+ reporter aequorin, MsDef1, MtDef4 and their cognate peptides were each shown to perturb Ca 2+ homeostasis in specific and distinct ways, and the disruptive effects of MsDef1 on Ca 2+were mediated by glucosylceramide. Together, our results demonstrate that MsDef1 and MtDef4 differ markedly in their antifungal properties and specific domains within their γ-core motifs play important roles in their different modes of antifungal action.

No abstract

In order to handle the safety problems in mobile communication systems, a mobile identity authentication scheme based on QKD and IBE is proposed. First, the quantum key distribution technology is introduced to handle the safety problems between the private key generator and the cloud services. Next, the IBE algorithm is introduced to encrypt IMSI which makes the scheme more flexible and more efficient. Finally, the quantum time parameter is proposed to manage users’ secret key. Comparing with the existing schemes, the proposed scheme can make full use of the advantages of the QKD and IBE. The mobile identity authentication scheme based on QKD and IBE can be more safe and more efficient.