Project description:We report the transcriptomic comparisions between key processes required for various stages of fungal carnivory in nematode-trapping fungus Arthrobotrys oligospora when induced with nematodes. The reference assembly used for remapping is A. oligospora TWF154 (GenBank assembly accession: GCA_004768765.1)
Project description:We report the transcriptomic comparisions between ku70 control and ste12 mutant strains in nematode-trapping fungus Arthrobotrys oligospora when induced with nematodes. Fungal Ste12 transcription factor and the upstream MAPK cascade are highly conserved and plays a role in host sensing and pathogenesis in various fungal pathogens. Identification of Ste12-dependent in A. oligospora may provide further insights into the molecular mechanisms of nematode-sensing and trap morphogenesis. The reference assemly used for remapping is A. oligospora TWF154 (GenBank assembly accession: GCA_004768765.1)
Project description:Rab GTPases regulate vesicle trafficking in organisms and play crucial roles in growth and development. Arthrobotrys oligospora is a representative species of nematode-trapping (NT) fungi, it can produce trapping devices for nematode predation. Our previous study found that deletion of Aorab7A abolished the trap formation and sporulation. Here, we investigated the regulatory mechanism of AoRab7A using transcriptomic, biochemical, and phenotypic comparisons. Transcriptome analysis, yeast library screening, and Y2H assays identified two vacuolar protein sorting (Vps) proteins, AoVps41 and AoVps35, as putative targets of AoRab7A. The deletion of Aovps41 and Aovps35 caused considerable defects in multiple phenotypic traits. We further found a close connection between AoRab7A, homotypic fusion, vacuolar protein sorting, and the retromer involved in vesicle-vacuole fusion, which triggered vacuolar fragmentation. Further transcriptome analysis showed that AoRab7A and AoVps35 play essential roles in many cellular processes and components including proteasomes, autophagy, fatty acid degradation, and ribosomes in A. oligospora. Furthermore, we verified that AoRab7A, AoVps41, and AoVps35 are involved in ribosome and proteasome functions. The absence of these proteins inhibited the biosynthesis of nascent proteins and enhanced ubiquitination. Our findings suggest that AoRab7A can interact with AoVps41 and AoVps35 to mediate vacuolar fusion and influence lipid droplet accumulation, autophagy, stress response, and secondary metabolism. These proteins are especially required for the conidiation and trap development of A. oligospora
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:Data from multiple high throughput technologies such as RNA sequencing (RNA-Seq) and protein mass spectrometry (MS/MS) are often used to assist in predicting eukaryote genome features such as genes, splice variants, and single nucleotide variants (SNVs). The genomes of parasitic nematodes causing neglected tropical diseases are often poorly annotated. Angiostrongylus costaricensis, a nematode that causes an intestinal inflammatory disease known as abdominal angiostrongyliasis (AA), is one example. Currently, no drugs or treatments are available for AA, a public health problem in Latin America, especially in Costa Rica and Brazil. The available genome of A. costaricensis, specific to the Costa Rica strain, is a draft version not supported by transcript- or protein-level evidence. This study used RNA-Seq and MS/MS data to perform an in-depth annotation of the A. costaricensis genome. Our prediction supplemented the reference annotation with a) novel coding and non-coding genes; b) pieces of evidence of alternative splicing generating new proteoforms; c) a list of SNVs specific to the Brazilian strain (Crissiumal). To the best of our knowledge, this is the first time that a multi-omics approach has been used to improve the genome annotation of a parasitic nematode. We hope this supplemented genome annotation can assist the future development of drugs to treat AA caused by either Brazil strain (Crissiumal) or Costa Rica strain.
Project description:Background Trombidid mites have a unique lifecycle in which only the larval stage is ectoparasitic. In the superfamily Trombiculoidea (“chiggers”), the larvae feed preferentially on vertebrates, including humans. Species in the genus Leptotrombidium are vectors of a potentially fatal bacterial infection, scrub typhus, which affects 1 million people annually. Moreover, chiggers can cause pruritic dermatitis (trombiculiasis) in humans and domesticated animals. In the Trombidioidea (velvet mites), the larvae feed on other arthropods and are potential biological control agents for agricultural pests. Here, we present the first trombidid mites genomes, obtained both for a chigger, Leptotrombidium deliense, and for a velvet mite, Dinothrombium tinctorium. Results Sequencing was performed on the Illumina MiSeq platform. A 180 Mb draft assembly for D. tinctorium was generated from two paired-end and one mate-pair library using a single adult specimen. For L. deliense, a lower-coverage draft assembly (117 Mb) was obtained using pooled, engorged larvae with a single paired-end library. Remarkably, both genomes exhibited evidence of ancient lateral gene transfer from soil-derived bacteria or fungi. The transferred genes confer functions that are rare in animals, including terpene and carotenoid synthesis. Thirty-seven allergenic protein families were predicted in the L. deliense genome, of which nine were unique. Preliminary proteomic analyses identified several of these putative allergens in larvae. Conclusions Trombidid mite genomes appear to be more dynamic than those of other acariform mites. A priority for future research is to determine the biological function of terpene synthesis in this taxon and its potential for exploitation in disease control. Project was jointly supervised by Stuart Armstrong and Ben Makepeace.