Project description:Genome annotation of the chelicerate Tetranychus urticae revealed the absence of many canonical immunity genes. T. urticae either does not mount an immune response or it induces uncharacterized immune pathways. To disentangle these two hypotheses, we performed transcriptomic analysis of mites injected with bacteria vs mites injected with LB-buffer. Two types of bacteria were injected: E. coli and B. megaterium and transcriptomes were sampled 3, 6 and 12 hrs after injection. We found no consistent differential expression after bacterial infection, supporting the hypothesis that spider mites do not mount an immune response. We hypothesize that the apparent absence of inducable immunity pathways in T. urticae is a result of relaxed selective pressure due to ecological factors.
Project description:We generated 38-bp Illumina reads from messenger RNA libraries from mites transferred from their preferred laboratory host, bean (Phaseolus vulgaris cv. California Red Kidney), to one of three hosts: bean, Arabidopsis thaliana (Bla-2 accession) and the tomato (Solanum lycopersicum; genotype Heinz 1706). Larvae were carefully collected from bean plants and transferred to the treatment plant. Mites were reared on these plants for ~24 hours, after which mites were collected for mRNA library preparation. Samples were a mix of males and females. The goal of the study was to identify genes that may underlie the ability of mites to be herbivores on different host plants.
Project description:Cyflumetofen is a novel acaricide on the international market with an unknown mode of action. Under laboratory conditions, we selected for high levels of cyflumetofen resistance in a susceptible mite strain and performed genome-wide gene-expression analysis. Differential expression between the resistant and susceptible strain was identified to study on the molecular level how mites develop resistance to this novel acaricide. Our results show that in T. urticae, the selection for cyflumetofen resistance resulted in a differential expression in only a limited number of genes. This transcriptomic study provides an unbiased look how cyflumetofen resistance triggers selection on the transcriptional level in T. urticae. 4 replicates for one comparison; per replicate 150 mites were pooled. Mites of the derived cyflumetofen resistant spider mite (cy5-labelled) were directly compared to mites of the ancestral susceptible strain (cy3-labelled).
Project description:Spider mites, including the two-spotted spider mite (Tetranychus urticae, TSSM) and the Banks grass mite (Oligonychus pratensis, BGM), are becoming increasingly important agricultural pests. The TSSM is an extreme generalist documented to feed on more than 1100 plant hosts. In contrast, the BGM is a grass specialist, with hosts including important cereal crops like maize, wheat, and sorghum. Historically, studies of plant-herbivore interactions have focused largely on insects. As such, far less is known about plant responses to spider mite herbivores, especially in grasses, and whether responses differ between generalist and specialist mites. To identify plant defense pathways responding to spider mites, we collected time course RNA-seq data from maize (Zea mays) infested with TSSMs and BGMs. Additionally, and as a comparison to the physical damage caused by spider mite feeding, a wounding treatment was also included. In total, four biological samples were generated per treatment.
Project description:We sequenced messenger RNA from mixed stages of the two-spotted spider mite (Tetranychus urticae) reared on bean (Phaseolus vulgaris cv California Red Kidney; the laboratory host plant for mites) and two Arabidopsis thaliana accessions which were considered to either be susceptible (Kondara) or resistant (Bla-2) to mite feeding. This pilot experiment was conducted to assess gene expression differences of mites grown on sensitive versus resistant Arabidopsis accessions, as well as differences in mites feeding on different host species. The expression data was used for gene model validation of genes predicted by EuGene in the spider mite genome and to assess gene expression levels.
Project description:CD4 T cells are essential mediators of the asthmatic process. We used the clinically relevant allergen house dust mites to induce signs of allergy in mice and performed gene expression arrays specifically on CD4 T cells infiltrating the lung Reference: IL-21-producing CD4+ T cells promote type 2 immunity to house dust mites
Project description:We generated 38-bp Illumina reads from messenger RNA libraries from mites transferred from their preferred laboratory host, bean (Phaseolus vulgaris cv. California Red Kidney), to one of three hosts: bean, Arabidopsis thaliana (Bla-2 accession) and the tomato (Solanum lycopersicum; genotype Heinz 1706). Larvae were carefully collected from bean plants and transferred to the treatment plant. Mites were reared on these plants for ~24 hours, after which mites were collected for mRNA library preparation. Samples were a mix of males and females. The goal of the study was to identify genes that may underlie the ability of mites to be herbivores on different host plants. Mites were transferred from host bean plants to two non-preferred hosts (Arabidopsis thaliana and tomato). RNA was then collected, and RNA-seq was performed on the Illumina platform. For each of three host plants, three biological replicates were generated.
Project description:We sequenced messenger RNA from mixed stages of the two-spotted spider mite (Tetranychus urticae) reared on bean (Phaseolus vulgaris cv California Red Kidney; the laboratory host plant for mites) and two Arabidopsis thaliana accessions which were considered to either be susceptible (Kondara) or resistant (Bla-2) to mite feeding. This pilot experiment was conducted to assess gene expression differences of mites grown on sensitive versus resistant Arabidopsis accessions, as well as differences in mites feeding on different host species. The expression data was used for gene model validation of genes predicted by EuGene in the spider mite genome and to assess gene expression levels. Examination of gene expression of spider mites reared on beans and two Arabidopsis accessions (Kondara and Bla-2).
Project description:Proteins produced in the salivary glands of arthropod herbivores can function as effectors to modify plant defense responses. To obtain a set of candidate, salivary gland specific genes for the mite herbivore Tetranychus urticae, mites were dissected and the head region was recovered. Specifically, the proterosoma was dissected from 250 mites. This includes the salivary glands, and other nearby tissue (given their small size, exact micro-dissection of salivary glands was not possible). As a reference for assessing differential expression to identify genes that might be salivary gland specific, three replicates of 100 whole mites were used. Female mites, which are much larger than males, were used in all cases for collection of RNA.
Project description:CD4 T cells are essential mediators of the asthmatic process. We used the clinically relevant allergen house dust mites to induce signs of allergy in mice and performed gene expression arrays specifically on CD4 T cells infiltrating the lung Reference: IL-21-producing CD4+ T cells promote type 2 immunity to house dust mites Primary CD4+ T cells were isolated from mice sensitised and challenged to either house dust mites or PBS. Purification of CD4 T cells was performed by flow cytometry. RNA was isolated, converted to cDNA and then hybridised on Affymetrix GeneChip Mouse Gene 2.0 ST Arrays