Project description:To identify accessible chromatin regions in the human host cells during Toxoplasma parasite infection (uninfected, RH-infected and Pru-infected human foreskin fibroblasts) and in the obligate intracellular parasite Toxoplasma gondii (Type 1 RH strain and Type 2 Pru strain), ATAC-seq was performed.
Project description:Intracellular microbes have evolved efficient strategies for transitioning from one cell to another in a process termed intercellular transmission. Here we show that host cell transmission of the obligate intracellular parasite Toxoplasma gondii is closely tied to specific cell cycle distributions, with egress and reinvasion occurring most proficiently by parasites in the G1 phase. We also reveal that Toxoplasma undergoes marked changes in mRNA expression when transitioning from the extracellular environment to its intracellular niche. These mRNA level changes reflect a modal switch from expression of proteins involved in invasion, motility and signal transduction in extracellular parasites to expression of metabolic and DNA replication proteins in intracellular parasites. Host cell binding and signalling associated with the discharge of parasite secretory proteins was not sufficient to induce this switch in gene expression, suggesting that the regulatory mechanisms responsible are tied to the establishment of the intracellular environment. The genes whose expression increased after parasite invasion belong to a progressive cascade known to underlie the parasite division cycle indicating that the unique relationship between the G1 phase and invasion effectively synchronizes short-term population growth. This work provides new insight into how this highly successful parasite competently transits from cell to cell. Three sample types were harvested: extracellular, intracellular 0hr, intracellular 2hr. 2 replicates each. Expression for >80% of the regulated genes exhibits a steady downregulation during invasion.
Project description:The sexually transmitted parasite Trichomonas vaginalis is often found in symbiosis with the obligate intracellular pathogen Mycoplasma hominis. M. hominis is itself an opportunistic pathogen of the female reproductive tract associated with bacterial vaginosis. The goal of this experiment was to identify the effects of each pathogen individually and in symbiosis on host cell gene expression.
Project description:Intracellular microbes have evolved efficient strategies for transitioning from one cell to another in a process termed intercellular transmission. Here we show that host cell transmission of the obligate intracellular parasite Toxoplasma gondii is closely tied to specific cell cycle distributions, with egress and reinvasion occurring most proficiently by parasites in the G1 phase. We also reveal that Toxoplasma undergoes marked changes in mRNA expression when transitioning from the extracellular environment to its intracellular niche. These mRNA level changes reflect a modal switch from expression of proteins involved in invasion, motility and signal transduction in extracellular parasites to expression of metabolic and DNA replication proteins in intracellular parasites. Host cell binding and signalling associated with the discharge of parasite secretory proteins was not sufficient to induce this switch in gene expression, suggesting that the regulatory mechanisms responsible are tied to the establishment of the intracellular environment. The genes whose expression increased after parasite invasion belong to a progressive cascade known to underlie the parasite division cycle indicating that the unique relationship between the G1 phase and invasion effectively synchronizes short-term population growth. This work provides new insight into how this highly successful parasite competently transits from cell to cell.
Project description:We use RNA-Seq to investigate gene expression differences in response to saltwater exposure by the larval stages of the obligate freshwater mosquito Anopheles coluzzii (formerly An. gambiae "M" form), and the euryhaline An. merus. After rearing in freshwater, both young and old larval instars of each species were briefly (6 h) exposed to either saltwater (SW) or freshwater (FW) conditions to test the impact of salinity on mRNA levels.
Project description:Polynucleobacter asymbioticus strain QLW-P1DMWA-1T represents a group of highly successful heterotrophic planktonic bacteria, dwelling in freshwater systems (lakes, ponds, and streams) across all climatic zones and across all continents. This includes habitats characterised by strongly fluctuating environmental conditions. So the experiments were designed to mimick winter and summer scenarios with additional impact of UV irradiation. Comparative transcriptomic studies were conducted to analyse gene-expression levels in contrasting experimental conditions. Overall, molecular candidates were revealed that may contribute in rapid acclimatisation of this strain in their immediate environment.
Project description:Toxoplasma gondii (T. gondii) is an obligate intracellular parasite that can infect almost all warm-blooded animals, causing serious public health problems. Lysine crotonylation (Kcr) is a newly discovered posttranslational modification (PTM), which has been proved that is relevant to procreation regulation, active transcription and cell signaling pathway. However, the biological functions of crotonylation have not yet been reported in macrophages infected with T. gondii. In our study, we performed a ChIP-seq analysis of porcine alveolar macrophages infected with T. gondii RH to explore the relationship of histone Kcr with T. gondii infection.
Project description:We use RNA-Seq to investigate gene expression differences in response to saltwater exposure by the larval stages of the obligate freshwater mosquito Anopheles coluzzii (formerly An. gambiae "M" form), and the euryhaline An. merus.