and Distribution among Different Mosquito Vectors Is Affected by Tissue Localization and Host Species.

Microbial communities play an important role in the fitness of mosquito hosts. However, the factors shaping microbial communities in wild populations, with regard to interactions among microbial species, are still largely unknown. Previous research has demonstrated that two of the most studied mosquito symbionts, the bacteria and , seem to compete or not compete, depending on the genetic background of the reference mosquito host.

A Time Point Proteomic Analysis Reveals Protein Dynamics of Plasmodium Oocysts.

The oocyst is a sporogonic stage of Plasmodium development that takes place in the mosquito midgut in about 2 weeks. The cyst is protected by a capsule of unknown composition, and little is known about oocyst biology. We carried out a proteomic analysis of oocyst samples isolated at early, mid, and late time points of development.

Screening of the activity of sixty essential oils against plasmodium early mosquito stages in vitro and machine learning analysis reveals new putative inhibitors of malaria parasites.

Malaria, an infectious disease with a tremendous impact on human health is caused by Plasmodium parasites, and transmitted by Anopheles mosquitoes. New approaches to control the disease involve transmission blocking strategies aiming to target the parasite in the mosquito. Here, we investigated the putative inhibitory activity of essential oils and their components on the early mosquito stages of the parasite.

A Comprehensive Gender-related Secretome of Sexual Stages.

, the malaria parasite, undergoes a complex life cycle alternating between a vertebrate host and a mosquito vector of the genus In red blood cells of the vertebrate host, multiplies asexually or differentiates into gamete precursors, the male and female gametocytes, responsible for parasite transmission. Sexual stage maturation occurs in the midgut of the mosquito vector, where male and female gametes egress from the host erythrocytes to fuse and form a zygote. Gamete egress entails the successive rupture of two membranes surrounding the parasite, the parasitophorous vacuole membrane and the erythrocyte plasma membrane.

Plasmodium berghei Gamete Egress Protein is required for fertility of both genders.

Male and female Plasmodium gametocytes ingested by the Anopheles mosquitoes during a blood meal egress from the red blood cells by rupturing the two surrounding membranes, the parasitophorous vacuole and the red blood cell membranes. Proteins of the so-called osmiophilic bodies, (OBs), secretory organelles resident in the cytoplasm, are important players in this process. Once gametes emerge, the female is ready to be fertilized while the male develops into motile flagellar gametes.

A method for purification of Plasmodium oocysts from mosquito midguts.

Malaria parasites have a complex life cycle comprising development in two hosts, the vertebrate and the vector mosquito. In the gut of the mosquito, the parasite develops into the oocyst, which is settled beneath the epithelium and attached to the basal lamina of the gut until the maturation of the cyst and its rupture concomitant with the release of the sporozoites, the infectious form of the parasite. The oocyst represents the longest stage of the parasite life cycle but it is poorly understood, mainly because of the difficulties to separate the oocysts from the mosquito midgut tissue but also the lack of a robust method to reproduce this stage in vitro.

Malaria transmission through the mosquito requires the function of the OMD protein.

Ookinetes, one of the motile and invasive forms of the malaria parasite, rely on gliding motility in order to establish an infection in the mosquito host. Here we characterize the protein PBANKA_0407300 which is conserved in the Plasmodium genus but lacks significant similarity to proteins of other eukaryotes. It is expressed in gametocytes and throughout the invasive mosquito stages of P.

Identification of Plasmodium berghei Oocyst Rupture Protein 2 (ORP2) domains involved in sporozoite egress from the oocyst.

Sporozoites are the infective form of malaria parasites which are transmitted from the mosquito salivary glands to a new host in a mosquito blood meal. The sporozoites develop inside the sporogonic oocyst and it is crucial for the continuation of the life cycle that the oocyst ruptures to release sporozoites. We recently described two Plasmodium Oocyst Rupture Proteins (ORP1 and ORP2), localized at the oocyst capsule, that are each essential for rupture of the oocysts.

Ubiquitin Proteasome System as a Potential Drug Target for Malaria.

Parasites of Plasmodium genus are responsible for causing malaria in humans. Resistant strains to all available antimalarials can be found in several locations around the globe, including parasites resistant to the latest generation of combination drugs, such as piperaquine + artemisinin. Plasmodium develops between two completely different hosts such as a vertebrate one and the mosquito vector, thus it has the ability to adapt to very extreme and different environments.

Plasmodium falciparum GPCR-like receptor SR25 mediates extracellular K sensing coupled to Ca signaling and stress survival.

The malaria parasite Plasmodium falciparum is exposed, during its development, to major changes of ionic composition in its surrounding medium. We demonstrate that the P. falciparum serpentine-like receptor PfSR25 is a monovalent cation sensor capable of modulating Ca signaling in the parasites.

Structured illumination microscopy reveals actin I localization in discreet foci in Plasmodium berghei gametocytes.

Actin has important roles in Plasmodium parasites but its exact function in different life stages is not yet fully elucidated. Here we report the localization of ubiquitous actin I in gametocytes of the rodent model parasite P. berghei.

An Integrated Approach to Explore Composition and Dynamics of Cholesterol-rich Membrane Microdomains in Sexual Stages of Malaria Parasite.

Membrane microdomains that include lipid rafts, are involved in key physiological and pathological processes and participate in the entry of endocellular pathogens. These assemblies, enriched in cholesterol and sphingolipids, form highly dynamic, liquid-ordered phases that can be separated from the bulk membranes thanks to their resistance to solubilization by nonionic detergents. To characterize complexity and dynamics of detergent-resistant membranes of sexual stages of the rodent malaria parasite , here we propose an integrated study of raft components based on proteomics, lipid analysis and bioinformatics.

Release of Plasmodium sporozoites requires proteins with histone-fold dimerization domains.

The sporozoite, the stage of the malaria parasite transmitted by the mosquito, first develops for ∼2 weeks in an oocyst. Rupture of the oocyst capsule is required for release of sporozoites, which then transfer to the salivary gland where they are injected into a new host. Here we identify two parasite proteins that we call oocyst rupture proteins 1 (ORP1) and ORP2.

Distinct properties of the egress-related osmiophilic bodies in male and female gametocytes of the rodent malaria parasite Plasmodium berghei.

Gametogenesis is the earliest event after uptake of malaria parasites by the mosquito vector, with a decisive impact on colonization of the mosquito midgut. This process is triggered by a drop in temperature and contact with mosquito molecules. In a few minutes, male and female gametocytes escape from the host erythrocyte by rupturing the parasitophorous vacuole and the erythrocyte membranes.

Proteomic analysis of detergent-resistant membrane microdomains in trophozoite blood stage of the human malaria parasite Plasmodium falciparum.

Intracellular pathogens contribute to a significant proportion of infectious diseases worldwide. The successful strategy of evading the immune system by hiding inside host cells is common to all the microorganism classes, which exploit membrane microdomains, enriched in cholesterol and sphingolipids, to invade and colonize the host cell. These assemblies, with distinct biochemical properties, can be isolated by means of flotation in sucrose density gradient centrifugation because they are insoluble in nonionic detergents at low temperature.

The ETRAMP family member SEP2 is expressed throughout Plasmodium berghei life cycle and is released during sporozoite gliding motility.

The early transcribed membrane proteins ETRAMPs belong to a family of small, transmembrane molecules unique to Plasmodium parasite, which share a signal peptide followed by a short lysine-rich stretch, a transmembrane domain and a variable, highly charged C-terminal region. ETRAMPs are usually expressed in a stage-specific manner. In the blood stages they localize to the parasitophorous vacuole membrane and, in described cases, to vesicle-like structures exported to the host erythrocyte cytosol.

The Anopheles gambiae cE5, a tight- and fast-binding thrombin inhibitor with post-transcriptionally regulated salivary-restricted expression.

Mosquito saliva carries a large number of factors with anti-hemostatic, anti-inflammatory and immuno-modulatory activities. The cE5 protein was initially identified during an Anopheles gambiae salivary gland transcriptome study and later shown to share sequence similarity with anophelin, a thrombin inhibitor from the saliva of the New World mosquito Anopheles albimanus. The cE5 gene was found to encode different mRNA isoforms coexisting in several tissues of both male and female mosquitoes, a highly unusual profile for a gene potentially encoding an anti-thrombin and involved in blood feeding.

Erythrocyte remodeling in Plasmodium berghei infection: the contribution of SEP family members.

The malaria parasite Plasmodium largely modifies the infected erythrocyte through the export of proteins to multiple sites within the host cell. This remodeling is crucial for pathology and translocation of virulence factors to the erythrocyte surface. In this study, we investigated localization and export of small exported proteins/early transcribed membrane proteins (SEP/ETRAMPs), conserved within Plasmodium genus.

Dematin, a component of the erythrocyte membrane skeleton, is internalized by the malaria parasite and associates with Plasmodium 14-3-3.

The malaria parasite invades the terminally differentiated erythrocytes, where it grows and multiplies surrounded by a parasitophorous vacuole. Plasmodium blood stages translocate newly synthesized proteins outside the parasitophorous vacuole and direct them to various erythrocyte compartments, including the cytoskeleton and the plasma membrane. Here, we show that the remodeling of the host cell directed by the parasite also includes the recruitment of dematin, an actin-binding protein of the erythrocyte membrane skeleton and its repositioning to the parasite.

The Anopheles gambiae salivary protein gSG6: an anopheline-specific protein with a blood-feeding role.

The Anopheles gambiae salivary gland protein 6 (gSG6) is a small protein specifically found in the salivary glands of adult female mosquitoes. We report here the expression of a recombinant form of the protein and we show that in vivo gSG6 is expressed in distal-lateral lobes and is secreted with the saliva while the female mosquito probes for feeding. Injection of gSG6 dsRNA into adult A.

Egress of Plasmodium berghei gametes from their host erythrocyte is mediated by the MDV-1/PEG3 protein.

Malaria parasites invade erythrocytes of their host both for asexual multiplication and for differentiation to male and female gametocytes - the precursor cells of Plasmodium gametes. For further development the parasite is dependent on efficient release of the asexual daughter cells and of the gametes from the host erythrocyte. How malarial parasites exit their host cells remains largely unknown.