Project description:Genomic assembly of nematode Thelazia callipaeda, as part of the 50 Helminth Genomes Initiative sequencing of the parasitic worms that have the greatest impact on human, agricultural and veterinary disease and cause significant global health issues particularly in the developing world, or those used as model organisms.
Project description:There is mounting evidence for the role of epigenetic processes in the regulation of plant responses to a wide range of external stimuli. Despite their importance, the significance of epigenetic processes in plant-pathogen interactions remain poorly understood. So far, the role of histone modifications has not been investigated at genome wide level in plant-nematode interactions, although their expression levels are altered in nematode-induced galls. In this study, we first applied chemical inhibitors of histone modifying enzymes on rice plants. Despite theirdistinct effects on histone modifications, application of different concentrations of Niconinamide, sulfamethazine and fumaric acid lead to reduced susceptibility to nematode infection. Similarly, two overexpression lines of histone lysine methyltransferases and one histone deacetylase were analyzed in an infection assay with nematodes, showing contrasting results in susceptibility. These data indicate that histone modifications can affect plant defence against nematodes in rice. To further investigate their effect, the genome-wide level of three histone marks namely H3K9ac, H3K9me2 and H3K27me3 was studied by chromatin-immunoprecipitation (ChIP)-sequencing on nematode-induced galls in comparison with control root tips.
Project description:Plant-parasitic cyst nematodes induce the formation of hypermetabolic feeding sites, termed syncytia, as their sole source of nutrients. The formation of the syncytium is orchestrated by the nematode in part by modulation of phytohormone responses, including cytokinin. In response to infection by the nematode H. schachtii, cytokinin signaling is transiently induced at the site of infection and in the developing syncytium. Arabidopsis lines with reduced cytokinin sensitivity show reduced susceptibility to nematode infection, indicating that cytokinin signaling is required for optimal nematode development. Furthermore, lines with increased cytokinin sensitivity also exhibit reduced nematode susceptibility. To ascertain why cytokinin hypersensitivity reduces nematode parasitism, we examined the transcriptomes in wild-type and a cytokinin-hypersensitive type-A arr Arabidopsis mutant in response to H. schachtii infection. Genes involved in the response to biotic stress and defense response were elevated in the type-A arr mutant in the absence of nematodes and were hyper-induced following H. schachtii infection, which suggests that the Arabidopsis type-A arr mutants impede nematode development because they are primed to respond to pathogen infection. These results suggest that cytokinin signaling is required for optimal H. schachtii parasitism of Arabidopsis, but that elevated cytokinin signaling triggers a heightened immune response to nematode infection.
Project description:We report the presence of circulating miRNAs released by the filarial nematode Dirofilaria immitis into the host (Canis familiaris) bloodstream.
