THE RELATIONSHIP OF EXFLAGELLATION IN AVIAN PLASMODIA TO pH AND IMMUNITY IN THE MOSQUITO1

Micks, Don W.; Caires, P. F. De; Franco, Luciano

doi:10.1093/oxfordjournals.aje.a119234

Cited by 17 publications

(15 citation statements)

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“…The method used to solubilize and purify the mosquitocidal protein does not require the use of denaturing or reducing agents and therefore results in a highly active toxin. These solubilization conditions closely resemble the conditions found in the insect midgut (6,9,20,23).…”

Section: Discussionsupporting

confidence: 67%

Purification of the mosquitocidal and cytolytic proteins of Bacillus thuringiensis subsp. israelensis

Hurley¹,

Bulla²,

Andrews³

1987

Appl Environ Microbiol

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Two proteins from parasporal crystals of Bacillus thuringiensis subsp. israelensis were purified to electrophoretic homogeneity by gel filtration and anion-exchange chromatography. The larger of the two proteins (molecular weight, 68,000) was not cytolytic, whereas the smaller protein (molecular weight, 28,000) was highly cytolytic when assayed against rat erythrocytes. When these proteins were assayed against larvae of the yellow fever mosquito, Aedes aegypti, the larger protein was at least 100-fold more toxic than the smaller protein. Although proteolytic activity was not detected in solubilized crystals nor in purified protein preparations, the toxin (molecular weight, 68,000) was readily degraded to smaller, nontoxic molecules, even when maintained at 4°C. Mixtures of the two purified proteins were significantly more toxic to mosquito larvae than was either protein alone. Thus, it is likely that both the mosquitocidal and the cytolytic protein play roles in the overall insecticidal action of the parasporal crystal produced by this bacterium.

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Section: Discussionsupporting

confidence: 67%

Purification of the mosquitocidal and cytolytic proteins of Bacillus thuringiensis subsp. israelensis

Hurley¹,

Bulla²,

Andrews³

1987

Appl Environ Microbiol

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“…S4). Gametogenesis was induced in gametocyte cultures of wt 3D7, Δ377/G5, Δ377/B7 and Δ377/E4 by lowering the temperature to 30°C and increasing pH to 8.2 (Micks et al ., 1948). Samples were removed 15 min after the induction and immediately fixed in suspension with 4% paraformaldehyde/0.075% glutaraldehyde.…”

Section: Methodsmentioning

confidence: 99%

The role of osmiophilic bodies and Pfg377 expression in female gametocyte emergence and mosquito infectivity in the human malaria parasite Plasmodium falciparum

Koning-Ward

Olivieri

Bertuccini

et al. 2007

Molecular Microbiology

100

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SummaryOsmiophilic bodies are membrane-bound vesicles, found predominantly in Plasmodium female gametocytes, that become progressively more abundant as the gametocyte reaches full maturity. These vesicles lie beneath the subpellicular membrane of the gametocyte, and the release of their contents into the parasitophorous vacuole has been postulated to aid in the escape of gametocytes from the erythrocyte after ingestion by the mosquito. Currently, the only protein known to be associated with osmiophilic bodies in Plasmodium falciparum is Pfg377, a gametocytespecific protein expressed at the onset of osmiophilic body development. Here we show by targeted gene disruption that Pfg377 plays a fundamental role in the formation of these organelles, and that female gametocytes lacking the full complement of osmiophilic bodies are significantly less efficient both in vitro and in vivo in their emergence from the erythrocytes upon induction of gametogenesis, a process whose timing is critical for fertilization with the short-lived male gamete. This reduced efficiency of emergence explains the significant defect in oocyst formation in mosquitoes fed blood meals containing Pfg377-negative gametocytes, resulting in an almost complete blockade of infection.

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“…2002). Asexual parasites do not survive when taken up by a vector in a blood meal, but the gametocytes rapidly differentiate into gametes and fertilization occurs within an hour (Micks et al. 1948; Sinden 1983a,b; Janse et al.…”

Section: Trait Variation In the Life Cycle Of Malaria Parasitesmentioning

confidence: 99%

SYNTHESIS: Plastic parasites: sophisticated strategies for survival and reproduction?

Reece

Ramiro

Nussey

2009

Evolutionary Applications

110

149

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Adaptive phenotypic plasticity in life history traits, behaviours, and strategies is ubiquitous in biological systems. It is driven by variation in selection pressures across environmental gradients and operates under constraints imposed by trade-offs. Phenotypic plasticity has been thoroughly documented for multicellular taxa, such as insects, birds and mammals, and in many cases the underlying selective pressures are well understood. Whilst unicellular parasites face many of the same selective pressures and trade-offs, plasticity in their phenotypic traits has been largely overlooked and remains poorly understood. Here, we demonstrate that evolutionary theory, developed to explain variation observed in the life-history traits of multicellular organisms, can be applied to parasites. Though our message is general – we can expect the life-histories of all parasites to have evolved phenotypic plasticity – we focus our discussion on malaria parasites. We use an evolutionary framework to explain the trade-offs that parasites face and how plasticity in their life history traits will be expressed according to changes in their in-host environment. Testing whether variation in parasites traits is adaptive will provide new and fundamental insights into the basic biology of parasites, their epidemiology and the processes of disease during individual infections.

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THE RELATIONSHIP OF EXFLAGELLATION IN AVIAN PLASMODIA TO pH AND IMMUNITY IN THE MOSQUITO1

Cited by 17 publications

References 0 publications

Purification of the mosquitocidal and cytolytic proteins of Bacillus thuringiensis subsp. israelensis

Purification of the mosquitocidal and cytolytic proteins of Bacillus thuringiensis subsp. israelensis

The role of osmiophilic bodies and Pfg377 expression in female gametocyte emergence and mosquito infectivity in the human malaria parasite Plasmodium falciparum

SYNTHESIS: Plastic parasites: sophisticated strategies for survival and reproduction?

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