Project description:We report the dual RNA-sequencing of host and pathogen transcriptomes during Plasmodium berghei liver-stage development in vitro. Unlike traditional transcriptomic approaches that analyze RNA reads separately from host and pathogen, a dual-approach maps the mixed reads to each annotated genome within samples of pathogen-infected host cells. This is a powerful method, as host and pathogen transcriptomes can be analyzed simultaneously. We have taken advantage of this dual-RNA sequencing approach in order to gain insight into Plasmodium liver stage development within host hepatocytes. Huh7.5.1 hepatocytes were infected in vitro with P. berghei sporozoites freshly dissected from infected Anopheles stephansi mosquitos, and cells were collected throughout liver-stage development. This included samples collected at time zero (uninfected hepatocytes and sporozoites before infection), time 24 hours post infection (when the sporozoites have transformed into trophozoites), and time 48-50 hours post infection (when the trophozoites have transformed into liver-stage schizonts).
Project description:Transcriptional profiling of gametocyte non-producer lines in Plasmodium berghei Transcriptome of gametocyte non producer lines (natural and genetic KO) and parental (820) lines. The aim of the study was to identify key genes involved in the decision to commit to gametocytogenesis in Plasmodium berghei. These microarrays compare naturally selected lines that do not produce gametocytes, and the parental line and additionally a genetic knock out of AP2-G PBANKA_143750. Data published Sinha, Hughes, et, al Nature tbc.
Project description:Many eukaryotic developmental and cell fate decisions are effected post-transcriptionally that mechanistically involve RNA binding proteins as regulators of translation of key mRNAs. In the unicellular eukaryote malaria parasite, Plasmodium, one of the most dramatic changes in cell morphology and function occurs during transmission between mosquito and human host. In the mosquito salivary glands, Plasmodium sporozoites are slender, motile and remain infectious for several weeks; only after transmission and liver cell invasion, does the parasite rapidly transform into a round, non-motile exo-erythrocytic form (EEF) that gives rise to thousands of infectious merozoites to be released into the blood stream. Here we demonstrate a Plasmodium homolog of the RNA binding protein, Pumilio, as a key regulator of the sporozoite to EEF transformation. In the absence of Pumilio-2 (Puf2) Plasmodium berghei sporozoites initiate early stage EEF development inside mosquito salivary glands with characteristic morphological changes; puf2- salivary gland sporozoites lose gliding motility, cell traversal ability and are less infective. Global expression profiling confirmed that transgenic parasites exhibit genome-wide transcriptional adaptations typical for Plasmodium intra-hepatic development. The data demonstrate that Puf2 is a key player in regulating developmental control, and imply that transformation of salivary gland-resident sporozoites into early liver stage parasites is regulated by a post-translational mechanism.
Project description:Salivary glands are the only mosquito tissue invaded by Plasmodium sporozoites being a key stage for the effective parasite transmission and maturation, making knowledge regarding Anopheles sialome highly relevant to understand this process. In this study, we report for the first time a transcriptomic analysis using RNA-seq of An. gambiae infected by P. berghei.
Project description:Transcriptional profiling of gametocyte non-producer lines in Plasmodium berghei Transcriptome of gametocyte non producer lines (natural and genetic KO) and parental (820) lines. The aim of the study was to identify key genes involved in the decision to commit to gametocytogenesis in Plasmodium berghei. These microarrays compare naturally selected lines that do not produce gametocytes, and the parental line and additionally a genetic knock out of AP2-G PBANKA_143750. Data published Sinha, Hughes, et, al Nature tbc. 2- colour microarray comparing to common background pool (containing all life cycle stages). Replicates of different life cycle stages of gametocyte non-producer lines and wild tye (WT) parental control lines
Project description:Malaria sporozoites, the form transmitted by mosquitoes, are quiescent while in the insect salivary glands. It is only after the sporozoites are deposited in the host’s skin, migrate to the liver and infect hepatocytes that the parasites continue the life cycle. We show that the sporozoite latency is an active process that requires phosphorylation of the eukaryotic initiation factor-2α (eIF2α) by a sporozoite-specific kinase. Inactivation of the kinase gene leads to an overall enhancement of protein synthesis including of silenced liver stage proteins, and inhibits transmission of malaria. Specific inhibition of the eIF2α phosphatase by salubrinal has the opposite effect. Thus, to prevent premature transformation into liver stages, Plasmodium sporozoites exploit the same mechanism that regulates stress responses in mammalian cells.