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Ecological influences on the behaviour and fertility of malaria parasites.

Carter LM, Pollitt LC, Wilson LG, Reece SE - Malar. J. (2016)

Bottom Line: Male gametes need to locate and fertilize females in the challenging environment of the mosquito blood meal, but remarkably little is known about the ecology and behaviour of male gametes.Specifically, the data confirm that: (a) rates of male gametogenesis vary when induced by the family of compounds (tryptophan metabolites) thought to trigger gamete differentiation in nature; and (b) complex relationships between gametogenesis and mating success exist across parasite species.In addition, the data reveal that (c) microparticles of the same size as red blood cells negatively affect mating success; and (d) instead of swimming in random directions, male gametes may be attracted by female gametes.

View Article: PubMed Central - PubMed

Affiliation: Ashworth Laboratories, School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.

ABSTRACT

Background: Sexual reproduction in the mosquito is essential for the transmission of malaria parasites and a major target for transmission-blocking interventions. Male gametes need to locate and fertilize females in the challenging environment of the mosquito blood meal, but remarkably little is known about the ecology and behaviour of male gametes.

Methods: Here, a series of experiments explores how some aspects of the chemical and physical environment experienced during mating impacts upon the production, motility, and fertility of male gametes.

Results and conclusions: Specifically, the data confirm that: (a) rates of male gametogenesis vary when induced by the family of compounds (tryptophan metabolites) thought to trigger gamete differentiation in nature; and (b) complex relationships between gametogenesis and mating success exist across parasite species. In addition, the data reveal that (c) microparticles of the same size as red blood cells negatively affect mating success; and (d) instead of swimming in random directions, male gametes may be attracted by female gametes. Understanding the mating ecology of malaria parasites, may offer novel approaches for blocking transmission and explain adaptation to different species of mosquito vectors.

No MeSH data available.


Related in: MedlinePlus

The density of microparticles affects mating success as measured by ookinete density. Mean ± SEM log10 transformed ookinetes/ml blood for each P. berghei line (Pb820 and PbANKA) in cultures in which media was replenished post-fertilization (a), or not replenished (b). N ranges from 3 to 6 independent infections for each mean
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Fig4: The density of microparticles affects mating success as measured by ookinete density. Mean ± SEM log10 transformed ookinetes/ml blood for each P. berghei line (Pb820 and PbANKA) in cultures in which media was replenished post-fertilization (a), or not replenished (b). N ranges from 3 to 6 independent infections for each mean

Mentions: To examine whether the physical presence of RBCs hinder microgametes by, for example, acting as barriers to motility, biocompatible particles (‘microparticles’) were used. Microparticles are similar to the size, shape and hydrophilic surface of murine RBCs but without the sialic acid surface coat (allowing the effect of physical interactions to be examined). The effect of adding microparticles at different densities to cultures of purified P. berghei gametocytes on ookinete density, as a measure of reproductive success, was examined. Whether replenishing media after fertilization increased ookinete yield was also tested. The effect of microparticle density on ookinete density (Fig. 4) was not dependent on whether media was replenished post fertilization (microparticle density*media: χ3,82 = 6.76, P = 0.08), but there were significant (main) effects of microparticle density (χ3,52 = 36.74, P < 0.0001) and media replenishment (χ1,72 = 8.33, P = 0.04). Increasing microparticle concentration from 0 to 60 % resulted in a 2- to 10-fold decrease in ookinete yield, depending on the parasite line and whether media was replenished (Table S3). Replenishing media post fertilization increased ookinete density by 12 %. Furthermore, whilst both P. berghei lines were affected by microparticles and media replenishment in the same way, P. berghei ANKA ookinete densities were 9 % lower overall than P. berghei 820 ookinete densities (Fig. 4; χ1,72 = 4.25, P = 0.04).Fig. 4


Ecological influences on the behaviour and fertility of malaria parasites.

Carter LM, Pollitt LC, Wilson LG, Reece SE - Malar. J. (2016)

The density of microparticles affects mating success as measured by ookinete density. Mean ± SEM log10 transformed ookinetes/ml blood for each P. berghei line (Pb820 and PbANKA) in cultures in which media was replenished post-fertilization (a), or not replenished (b). N ranges from 3 to 6 independent infections for each mean
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4835847&req=5

Fig4: The density of microparticles affects mating success as measured by ookinete density. Mean ± SEM log10 transformed ookinetes/ml blood for each P. berghei line (Pb820 and PbANKA) in cultures in which media was replenished post-fertilization (a), or not replenished (b). N ranges from 3 to 6 independent infections for each mean
Mentions: To examine whether the physical presence of RBCs hinder microgametes by, for example, acting as barriers to motility, biocompatible particles (‘microparticles’) were used. Microparticles are similar to the size, shape and hydrophilic surface of murine RBCs but without the sialic acid surface coat (allowing the effect of physical interactions to be examined). The effect of adding microparticles at different densities to cultures of purified P. berghei gametocytes on ookinete density, as a measure of reproductive success, was examined. Whether replenishing media after fertilization increased ookinete yield was also tested. The effect of microparticle density on ookinete density (Fig. 4) was not dependent on whether media was replenished post fertilization (microparticle density*media: χ3,82 = 6.76, P = 0.08), but there were significant (main) effects of microparticle density (χ3,52 = 36.74, P < 0.0001) and media replenishment (χ1,72 = 8.33, P = 0.04). Increasing microparticle concentration from 0 to 60 % resulted in a 2- to 10-fold decrease in ookinete yield, depending on the parasite line and whether media was replenished (Table S3). Replenishing media post fertilization increased ookinete density by 12 %. Furthermore, whilst both P. berghei lines were affected by microparticles and media replenishment in the same way, P. berghei ANKA ookinete densities were 9 % lower overall than P. berghei 820 ookinete densities (Fig. 4; χ1,72 = 4.25, P = 0.04).Fig. 4

Bottom Line: Male gametes need to locate and fertilize females in the challenging environment of the mosquito blood meal, but remarkably little is known about the ecology and behaviour of male gametes.Specifically, the data confirm that: (a) rates of male gametogenesis vary when induced by the family of compounds (tryptophan metabolites) thought to trigger gamete differentiation in nature; and (b) complex relationships between gametogenesis and mating success exist across parasite species.In addition, the data reveal that (c) microparticles of the same size as red blood cells negatively affect mating success; and (d) instead of swimming in random directions, male gametes may be attracted by female gametes.

View Article: PubMed Central - PubMed

Affiliation: Ashworth Laboratories, School of Biological Sciences, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.

ABSTRACT

Background: Sexual reproduction in the mosquito is essential for the transmission of malaria parasites and a major target for transmission-blocking interventions. Male gametes need to locate and fertilize females in the challenging environment of the mosquito blood meal, but remarkably little is known about the ecology and behaviour of male gametes.

Methods: Here, a series of experiments explores how some aspects of the chemical and physical environment experienced during mating impacts upon the production, motility, and fertility of male gametes.

Results and conclusions: Specifically, the data confirm that: (a) rates of male gametogenesis vary when induced by the family of compounds (tryptophan metabolites) thought to trigger gamete differentiation in nature; and (b) complex relationships between gametogenesis and mating success exist across parasite species. In addition, the data reveal that (c) microparticles of the same size as red blood cells negatively affect mating success; and (d) instead of swimming in random directions, male gametes may be attracted by female gametes. Understanding the mating ecology of malaria parasites, may offer novel approaches for blocking transmission and explain adaptation to different species of mosquito vectors.

No MeSH data available.


Related in: MedlinePlus