Project description:Purpose: To identify the putative high pathogenicity for fungal infection of nematodes of the nematode-trapping fungus Duddingtonia flagrans, RNA-seq was used to examine the transcriptional responses in three stages with the treatment of extraction of Caenorhabditis elegans. Methods:mRNA of three interaction stages (0h, 12h, 48h) were generated by deep sequencing, in triplicate, using Illumina Hiseq platforme,and 125 bp paired-end reads were generated.Then raw reads were firstly processed by in-house perl scripts and clean reads were obtained by removing reads containing adapter,poly-N and low quality reads. Clean reads were aligned to the reference genome using TopHat V2.0.12 (Duddingtonia flagrans genome with the accession number of MDKD00000000).Then HTSeq and DESeq were used to analyse the gene expression level. Results: After sequencing, 81.8% of the genes predicted in genome of Duddingtonia flagrans were expressed (FPKM>1) in the samples free of treatment of extraction of Caenorhabditis elegans (0h). After treatment with nematode extracts for 12 h , 40.7% of predicted genes, including 1,752 up-regulated genes and 2,072 down-regulated genes, were found to be differentially expressed (padj<0.05, DESeq) compared to the genes at 0 h. Similarly, after treatment with nematode extracts for 48 h, 13.8% of predicted genes, including 673 up-regulated genes and 628 down-regulated genes, were found to be differentially expressed compared to the genes at 12 h.
Project description:Next Generation Sequencing analysis to examine the transcriptional responses of the nematode-trapping fungus Duddingtonia flagrans with the treatment of extraction of Caenorhabditis elegans
Project description:Genome and transcriptome sequencing of animal parasitic nematode destroying fungus Duddingtonia flagrans-A soul species in its genus
Project description:Animals protect themself from microbial attacks by robust skins or a cuticle as in Caenorhabditis elegans. Nematode-trapping fungi, like Arthrobotrys flagrans, overcome the cuticle barrier and colonize the nematode body. While lytic enzymes are important for infection, small-secreted proteins (SSPs) without enzymatic activity, emerge as crucial virulence factors. Here, we characterized NipA (nematode induced protein) which A. flagrans secretes at the penetration site. In the absence of NipA, A. flagrans required more time to penetrate C. elegans. Heterologous expression of the fungal protein in the epidermis of C. elegans led to blister formation. NipA contains 13 cysteines, 12 of which are likely to form disulfide bridges, and the remaining cysteine was crucial for blister formation. We hypothesize that NipA interferes with cuticle integrity to facilitate fungal entry. Genome-wide expression analyses of C. elegans expressing NipA revealed mis-regulation of genes associated with extracellular matrix (ECM) maintenance and innate immunity.
