Abstract
The protozoan Plasmodium falciparum has a complex life cycle in which asexual multiplication in the vertebrate host alternates with an obligate sexual reproduction in the anopheline mosquito. Apart from the apparent recombination advantages conferred by sex, P. falciparum has evolved a remarkable biology and adaptive phenotypes to insure its transmission despite the dangers of sex. This review mainly focuses on the current knowledge on commitment to sexual development, gametocytogenesis and the evolutionary significance of various aspects of gametocyte biology. It goes further than pure biology to look at the strategies used to improve successful transmission. Although gametocytes are inevitable stages for transmission and provide a potential target to fight malaria, they have received less attention than the pathogenic asexual stages. There is a need for research on gametocytes, which are a fascinating stage, responsible to a large extent for the success of P. falciparum.
Highlights
Plasmodium falciparum has the morbid characteristic of being the deadliest protozoan parasite of humans. It is an organism with an obligatory sexual reproduction which takes place in the mosquito midgut
The parasite migrates to the salivary glands to be injected into the human host. Before it can succeed sexually in the mosquito host, P. falciparum undergoes a puberty-like process in the human blood: an asexual parasite goes through a series of changes, which will lead to the generation of a sexually competent parasite
The present review focuses on specific points of commitment to sexual development – gametocytogenesis and gametocyte biology– especially those relevant to transmission and evolution of P. falciparum transmission strategies
Summary
Plasmodium falciparum has the morbid characteristic of being the deadliest protozoan parasite of humans. This might not reflect co-operation between conspecific clones, but it http://www.malariajournal.com/content/3/1/24 could be that competition between parasites increases the chances of transmission by creating an advantageous effect on the competiting clones This may be confirmed by the work of Arez and colleagues [144], who observed a lower proportion of mixed-genotype infections in the mosquito than in the human host. It has been proposed that frequencies of super-infection, modulated by cross-immunity between the phenotypes involved, may serve to constrain gametocyte production to levels less than would be optimal for transmission in a single-phenotype context [153] Another possible explanation is that the gametocyte number is kept low in order to reduce the damage mosquito stages are likely to inflict on their host [151]. When a high level of "stress" (immunity) arises, the parasite population would respond by restricting the expression of the diffusible molecule and, would stimulate a higher level of asexual parasites to develop sexually
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
