Response to social context has been documented in malaria parasites [21,76] and

Response to social context has been documented in malaria parasites [21,76] and these behaviours are determinants of howrstb.royalsocietypublishing.org Phil. Trans. R. Soc. B 369:Table 2. GSK2256098 custom synthesis Examples of phenotypic plasticity in parasite social behaviours. That phenotypes are a product of both genotypes and the environment, and how they interact, is well known, but often the environment is viewed as obscuring the connection between genes and phenotypes. However, how social behaviours are influenced by environmental variation matters because they affect virulence and transmission. Because multiple environmental factors change simultaneously during infections and virulence and transmission phenotypes are products of multiple social behaviours, parasites can produce a wide range of adaptive phenotypes faster by plasticity than when beneficial mutations or recombination are RP5264MedChemExpress RP5264 required to generate new phenotypes. behaviour/ trait developmental schedules what happens and why? In the host blood, cycles of asexual replication in many species of Plasmodium are tightly synchronized; individual parasites transit through each cell cycle stage and ultimately burst out of their red blood cells in unison and at particular times of day. The duration and synchronicity of cell cycles are plastic [105]. An adaptive basis of this plasticity is yet to be established but in-host competition and host immune responses are likely drivers [108]. Disrupted P. chabaudi schedules result in lower virulence (anaemia; [107]) but quiescence can also help Plasmodium falciparum tolerate antimalarial drugs [109]. lysis time Pi 2 bacteriophage must lyse their bacterial host (Pseudomonas fluorescens) to transmit. They evolve a plastic lysis time in which they kill host cells more rapidly when co-infecting host cells with other phage than when infecting alone [38]. Plasticity in lysis time evolved in phage lines in mixed-infection conditions owing to the frequent variability in whether they encounter co- or single infections in this treatment (the lysis time in single-infection conditions did not change or become plastic in response to selection). This plasticity enhances the competitive ability of phage since non-plastic phage have fewer mature propagules upon cell lysis and suggests virulence and transmission differ according to whether parasites are in single or mixed genotype infections. In addition, lysis inhibition (LIN) is a mechanism of burstsize increase and latent period extension induced by T4 bacteriophage secondary adsorption of T4-infected E. coli cells. This plastic growth strategy is an adaptation to environments containing high densities of T4-infected cells [110]: when T4-infected cell density is high, high densities of free phages are generated, uninfected cells are rapidly infected, secondary adsorption is likely and LIN is induced with high probability [110 ?113]. public goods The production of an iron-scavenging molecule (pyoverdin) by P. aeruginosa bacteria is a cooperative trait. Pyverdin production per bacterium is tightly regulated by the intracellular supply of free iron, leading to decreased per capita production at higher cell densities and increased production in the presence of non-producing cheats. This phenotypic plasticity significantly influences the costs and benefits of cooperation. Specifically, the investment of resources into pyoverdin production is reduced in iron-rich environments and at high cell densities, but increased under iron limit.Response to social context has been documented in malaria parasites [21,76] and these behaviours are determinants of howrstb.royalsocietypublishing.org Phil. Trans. R. Soc. B 369:Table 2. Examples of phenotypic plasticity in parasite social behaviours. That phenotypes are a product of both genotypes and the environment, and how they interact, is well known, but often the environment is viewed as obscuring the connection between genes and phenotypes. However, how social behaviours are influenced by environmental variation matters because they affect virulence and transmission. Because multiple environmental factors change simultaneously during infections and virulence and transmission phenotypes are products of multiple social behaviours, parasites can produce a wide range of adaptive phenotypes faster by plasticity than when beneficial mutations or recombination are required to generate new phenotypes. behaviour/ trait developmental schedules what happens and why? In the host blood, cycles of asexual replication in many species of Plasmodium are tightly synchronized; individual parasites transit through each cell cycle stage and ultimately burst out of their red blood cells in unison and at particular times of day. The duration and synchronicity of cell cycles are plastic [105]. An adaptive basis of this plasticity is yet to be established but in-host competition and host immune responses are likely drivers [108]. Disrupted P. chabaudi schedules result in lower virulence (anaemia; [107]) but quiescence can also help Plasmodium falciparum tolerate antimalarial drugs [109]. lysis time Pi 2 bacteriophage must lyse their bacterial host (Pseudomonas fluorescens) to transmit. They evolve a plastic lysis time in which they kill host cells more rapidly when co-infecting host cells with other phage than when infecting alone [38]. Plasticity in lysis time evolved in phage lines in mixed-infection conditions owing to the frequent variability in whether they encounter co- or single infections in this treatment (the lysis time in single-infection conditions did not change or become plastic in response to selection). This plasticity enhances the competitive ability of phage since non-plastic phage have fewer mature propagules upon cell lysis and suggests virulence and transmission differ according to whether parasites are in single or mixed genotype infections. In addition, lysis inhibition (LIN) is a mechanism of burstsize increase and latent period extension induced by T4 bacteriophage secondary adsorption of T4-infected E. coli cells. This plastic growth strategy is an adaptation to environments containing high densities of T4-infected cells [110]: when T4-infected cell density is high, high densities of free phages are generated, uninfected cells are rapidly infected, secondary adsorption is likely and LIN is induced with high probability [110 ?113]. public goods The production of an iron-scavenging molecule (pyoverdin) by P. aeruginosa bacteria is a cooperative trait. Pyverdin production per bacterium is tightly regulated by the intracellular supply of free iron, leading to decreased per capita production at higher cell densities and increased production in the presence of non-producing cheats. This phenotypic plasticity significantly influences the costs and benefits of cooperation. Specifically, the investment of resources into pyoverdin production is reduced in iron-rich environments and at high cell densities, but increased under iron limit.