Population variation in the metabolic response of deer mice to infection with Capillaria hepatica (Nematoda)

2001 ◽  
Vol 79 (4) ◽  
pp. 554-561 ◽  
Author(s):  
Shawn Meagher ◽  
Timothy P O'Connor
Keyword(s):  
Cold Stress ◽  
Metabolic Response ◽  
Host Population ◽  
Population Variation ◽  
Deer Mice ◽  
Negative Consequences ◽  
Capillaria Hepatica ◽  
Generation Times ◽  
Stress Maximum ◽  
Host Parasite

The effects of parasites on their hosts can vary among host populations, but few studies have examined geographic variation in host-parasite interactions. We examined the effects of Capillaria hepatica (Nematoda) infection on deer mice (Peromyscus maniculatus gracilis) from two different populations. Specifically, we measured the basal metabolic rate (BMR), cold-stress maximum oxygen consumption (MRpeak), metabolic scope (MRpeak/BMR), and thermogenic endurance of infected and uninfected mice from one population with, and a second population without, a history with C. hepatica. Infection had no effect on BMR, but did have effects on cold-stress measures. A previous study documented a significant relationship between survival and MRpeak in wild deer mice; hence, the effects of infection on the parameters that we measured could influence fitness. Only mice that had no historical association with C. hepatica displayed negative consequences of infection, which suggests that the historical host population has evolved mechanisms to cope with infection. Models of the evolution of virulence should include evolutionary responses of both hosts and parasites, particularly when systems involve macroparasites that have long generation times.

scholarly journals FUNCTIONAL GENOMICS OF ADAPTATION TO HYPOXIC COLD-STRESS IN HIGH-ALTITUDE DEER MICE: TRANSCRIPTOMIC PLASTICITY AND THERMOGENIC PERFORMANCE

Evolution ◽  
2013 ◽  
Vol 68 (1) ◽  
pp. 48-62 ◽  
Author(s):  
Zachary A. Cheviron ◽  
Alex D. Connaty ◽  
Grant B. McClelland ◽  
Jay F. Storz
Keyword(s):  
Cold Stress ◽  
Functional Genomics ◽  
High Altitude ◽  
Deer Mice

The effect of the acanthocephalan Pomphorhynchus laevis upon the respiration of its intermediate host, Gammarus pulex

Parasitology ◽  
1974 ◽  
Vol 68 (2) ◽  
pp. 271-284 ◽  
Author(s):  
A. E. Rumpus ◽  
C. R. Kennedy
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Host Population ◽  
Gammarus Pulex ◽  
Multiple Infections ◽  
Pomphorhynchus Laevis ◽  
Respiration Rates ◽  
Physiological Processes ◽  
Stage Of Development ◽  
Host Parasite

The respiration rates of individual Gammarus pulex infected by larval Pomphorhynchus laevis were investigated with particular reference to the stage of development of the host and parasite and to the water temperature. At 20°C the oxygen consumption of Gammarus of all sizes was reduced by an average of 19·3 % by the presence of cystacanths of the parasite, but was unaffected by the presence of acanthellae. It is considered that the small size of this larval stage, in relation to that of its host, is responsible for the failure to detect an effect. Multiple infections did not exert any greater effect upon host respiration than single cystacanths, nor did it appear that the parasite had different effects upon hosts of different sexes. At 10°C no significant differences were observed between the respiration rates of infected and uninfected gammarids. The parasite was probably still depressing the host respiration rate at this temperature, but the oxygen uptake of G. pulex is so low that the differences between infected and uninfected individuals were too small to be detected. The parasite has a direct effect upon the physiological processes of the host, but neither the mechanism of this nor the reasons for the different effects found in different host-parasite systems are yet understood. Despite the pronounced effect of P. laevis on respiration of individual hosts, its effect upon the oxygen consumption of a natural host population is small since only a small proportion of the population carries infections and water temperatures remain below 10°C for over half the year.

scholarly journals Assessing the direct and indirect effects of food provisioning and nutrient enrichment on wildlife infectious disease dynamics

2018 ◽  
Vol 373 (1745) ◽  
pp. 20170101 ◽  
Author(s):  
David J. Civitello ◽  
Brent E. Allman ◽  
Connor Morozumi ◽  
Jason R. Rohr
Keyword(s):  
Nutrient Enrichment ◽  
Management Strategies ◽  
Wildlife Disease ◽  
Host Population ◽  
Food Provisioning ◽  
Resource Subsidies ◽  
Predator Species ◽  
Interacting Species ◽  
Integrative View ◽  
Host Parasite

Anthropogenic resource supplementation can shape wildlife disease directly by altering the traits and densities of hosts and parasites or indirectly by stimulating prey, competitor or predator species. We first assess the direct epidemiological consequences of supplementation, highlighting the similarities and differences between food provisioning and two widespread forms of nutrient input: agricultural fertilization and aquatic nutrient enrichment. We then review an aquatic disease system and a general model to assess whether predator and competitor species can enhance or overturn the direct effects of enrichment. All forms of supplementation can directly affect epidemics by increasing host population size or altering parasite production within hosts, but food provisioning is most likely to aggregate hosts and increase parasite transmission. However, if predators or competitors increase in response to supplementation, they could alter resource-fuelled outbreaks in focal hosts. We recommend identifying the traits of hosts, parasites or interacting species that best predict epidemiological responses to supplementation and evaluating the relative importance of these direct and indirect mechanisms. Theory and experiments should examine the timing of behavioural, physiological and demographic changes for realistic, variable scenarios of supplementation. A more integrative view of resource supplementation and wildlife disease could yield broadly applicable disease management strategies. This article is part of the theme issue ‘Anthropogenic resource subsidies and host–parasite dynamics in wildlife’.

scholarly journals Prior exposure to long-day photoperiods alters immune responses and increases susceptibility to parasitic infection in stickleback

2020 ◽  
Vol 287 (1930) ◽  
pp. 20201017
Author(s):  
James R. Whiting ◽  
Muayad A. Mahmud ◽  
Janette E. Bradley ◽  
Andrew D. C. MacColl
Keyword(s):  
Immune Responses ◽  
Parasitic Infection ◽  
Population Variation ◽  
Host Susceptibility ◽  
Day Length ◽  
Previous Exposure ◽  
Parasite Abundance ◽  
Susceptibility To Infection ◽  
Long Day ◽  
Host Parasite

Seasonal disease and parasitic infection are common across organisms, including humans, and there is increasing evidence for intrinsic seasonal variation in immune systems. Changes are orchestrated through organisms' physiological clocks using cues such as day length. Ample research in diverse taxa has demonstrated multiple immune responses are modulated by photoperiod, but to date, there have been few experimental demonstrations that photoperiod cues alter susceptibility to infection. We investigated the interactions among photoperiod history, immunity and susceptibility in laboratory-bred three-spined stickleback (a long-day breeding fish) and its external, directly reproducing monogenean parasite Gyrodactylus gasterostei . We demonstrate that previous exposure to long-day photoperiods (PLD) increases susceptibility to infection relative to previous exposure to short days (PSD), and modifies the response to infection for the mucin gene muc2 and Treg cytokine foxp3a in skin tissues in an intermediate 12 L : 12 D photoperiod experimental trial. Expression of skin muc2 is reduced in PLD fish, and negatively associated with parasite abundance. We also observe inflammatory gene expression variation associated with natural inter-population variation in resistance, but find that photoperiod modulation of susceptibility is consistent across host populations. Thus, photoperiod modulation of the response to infection is important for host susceptibility, highlighting new mechanisms affecting seasonality of host–parasite interactions.

ASPECTS OF THE INTERACTION BETWEEN A CHALCID PARASITE AND ITS ALEURODID HOST

1967 ◽  
Vol 45 (4) ◽  
pp. 539-578 ◽  
Author(s):  
T. Burnett
Keyword(s):  
Larval Mortality ◽  
Trialeurodes Vaporariorum ◽  
Host Population ◽  
Population Variation ◽  
Encarsia Formosa ◽  
Greenhouse Whitefly ◽  
Parasite Abundance ◽  
Tomato Plants ◽  
Host Mortality ◽  
Dominant Process

Three populations of the greenhouse whitefly, Trialeurodes vaporariorum, and its chalcid parasite Encarsia formosa were propagated each year for three consecutive years on tomato plants in the greenhouse. The abundance of the host and parasite species fluctuated either with peaks of increasing amplitude, with peaks of decreasing amplitude, or with irregular peaks. The dominant process in the interaction was the occurrence of two qualitatively different types of host larval mortality: (a) parasitization, and (b) almost immediate killing after attack by adult parasites. Fluctuations in host and parasite abundance resulted from the almost immediate killing of small host larvae and the death of the short-lived adult parasites. The parasite population tended to destroy similar percentages of host populations of different densities but host mortality was also related to the age structure of the host population. Variation in host reproduction, caused by differences in rearing temperature and by seasonal variation in the physical environment, influenced host and parasite densities.

scholarly journals The mode of host–parasite interaction shapes coevolutionary dynamics and the fate of host cooperation

2012 ◽  
Vol 279 (1743) ◽  
pp. 3742-3748 ◽  
Author(s):  
Benjamin J. Z. Quigley ◽  
Diana García López ◽  
Angus Buckling ◽  
Alan J. McKane ◽  
Sam P. Brown
Keyword(s):  
Stochastic Modelling ◽  
Host Population ◽  
Social Traits ◽  
The Social ◽  
Population Structures ◽  
Modelling Techniques ◽  
Virus Interactions ◽  
Host Parasite ◽  
The Impact ◽  
Genetic Specificity

Antagonistic coevolution between hosts and parasites can have a major impact on host population structures, and hence on the evolution of social traits. Using stochastic modelling techniques in the context of bacteria–virus interactions, we investigate the impact of coevolution across a continuum of host–parasite genetic specificity (specifically, where genotypes have the same infectivity/resistance ranges (matching alleles, MA) to highly variable ranges (gene-for-gene, GFG)) on population genetic structure, and on the social behaviour of the host. We find that host cooperation is more likely to be maintained towards the MA end of the continuum, as the more frequent bottlenecks associated with an MA-like interaction can prevent defector invasion, and can even allow migrant cooperators to invade populations of defectors.

An Experimental Field Study to Examine Whether Capillaria Hepatica (Nematoda) Can Limit House Mouse Populations in Eastern Australia.

1995 ◽  
Vol 22 (1) ◽  
pp. 31 ◽  
Author(s):  
GR Singleton ◽  
GR Singleton ◽  
LK Chambers ◽  
LK Chambers ◽  
DM Spratt ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Host Population ◽  
Rapid Decline ◽  
Low Density ◽  
Noticeable Effect ◽  
Mouse Population ◽  
Apparent Lack ◽  
Capillaria Hepatica ◽  
Experimental Field ◽  
Eastern Australia

A replicated experimental field investigation to examine the effect of the nematode parasite Capillaria hepatica on populations of Mus domesticus is described. A 2-year study was conducted at 7 sites with matching farming practices, soil types, topography and habitat heterogeneity on the Darling Downs in south-eastern Queensland, Australia, where mice cause substantial economic, social and environmental problems. A 4 km2 sampling zone was designated on each site and sites were assigned randomly to one of 3 untreated and 4 treated groups. The parasite was released successfully on 3 occasions at 3 markedly different stages of mouse population dynamics. The first release was in winter 1992 into a low-density, non-breeding population. Mice on treated sites had significantly lower survival for 6 months after the release than mice on untreated sites. The parasite had a relatively high impact on survival of young mice (<72 mm long) 2 months after its release. The greatest impact on old mice (>76 mm) occurred a month later. The most pronounced effects of C. hepatica on mouse abundance occurred during the 4 months after its release (June-September). Mice on the untreated sites, however, had poor survival in September, so by October their population abundance was at a level similar to that of the treated populations. Once breeding began in mid-October C. hepatica had no noticeable effect on mouse population dynamics. This was because the parasite (i) had no effect on breeding of mice, (ii) had minimal transmission and (iii) had a diminishing effect on survival after October. The apparent lack of transmission of C. hepatica was probably due to a combination of low population density, the transient nature of the mouse population and predominantly dry weather for 6 months after the release. A second release was made in February 1993 into a breeding, medium-density host population that was rapidly increasing in abundance. Less than 2% of the population was affected during the release so interest focused on transmission rather than the effect of the parasite on the host's demographic machinery. Transmission did occur at a low rate and the parasite persisted for 4.5 months (to June) when it was decided to boost the proportion of mice infected in order to follow its effect on the overwintering population and the demographic effects during the next breeding season. This late release was compromised by synchronous, widespread and rapid decline in mouse densities. Densities fell from greater than 500 ha to less than 1 ha in less than 6 weeks. Two messages emerge from these studies. First, C. hepatica will not limit mouse populations if it is released into a low-density population during a long dry period on the Darling Downs. Second, more information is needed about the factors that influence the survival and transmission of the parasite under field conditions.

The regulation of host population growth by parasitic species

Parasitology ◽  
1978 ◽  
Vol 76 (2) ◽  
pp. 119-157 ◽  
Author(s):  
R. M. Anderson
Keyword(s):  
Population Growth ◽  
Reproductive Potential ◽  
Parasite Burden ◽  
Host Population ◽  
Parasitic Species ◽  
Regulatory Influence ◽  
Host Mortality ◽  
Parasite Reproduction ◽  
Over Dispersion ◽  
Host Parasite

SummaryThe nature of parasitism at the population level is defined in terms of the parasite's influence on the natural intrinsic growth rate of its host population. It is suggested that the influence on this rate is related to the average parasite burden/host and hence to the statistical distribution of parasites within the host population.Theoretical models of host–parasite associations are used to assess the regulatory influence of parasitic species on host population growth. Model predictions suggest that three specific groups of population processes are of particular importance: over-dispersion of parasite numbers/host, density dependence in parasite mortality or reproduction and parasite-induced host mortality that increases faster than linearly with the parasite burden. Other population mechanisms are shown to have a destabilizing influence, namely: parasite-induced reduction in host reproductive potential, direct parasite reproduction within the host and time delays in the development of transmission stages of the parasite.These regulatory and destabilizing processes are shown to be commonly observed features of natural host-parasite associations. It is argued that interactions in the real world are characterized by a degree of tension between these regulatory and destabilizing forces and that population rate parameter values in parasite life-cycles are very far from being a haphazard selection of all numerically possible values. It is suggested that evolutionary pressures in observed associations will tend to counteract a strong destabilizing force by an equally strong regulatory influence. Empirical evidence is shown to support this suggestion in, for example, associations between larval digeneans and molluscan hosts (parasite-induced reduction in host reproductive potential counteracted by tight density-dependent constraints on parasite population growth), and interactions between protozoan parasites and mammalian hosts (direct parasite reproduction counteracted by a well-developed immunological response by the host).The type of laboratory and field data required to improve our understanding of the dynamical properties of host–parasite population associations is discussed and it is suggested that quantitative measurement of rates of parasite-induced host mortality, degrees of over-dispersion, transmission rates and reproductive and mortality rates of both host and parasite would provide an important first step. The value of laboratory work in this area is demonstrated by reference to studies which highlight the regulatory influence of parasitic species on host population growth.

Effect of Host Distribution on the Reproduction of Encarsia formosa Gahan (Hymenoptera: Chalcidoidea)

1958 ◽  
Vol 90 (3) ◽  
pp. 179-191 ◽  
Author(s):  
T. Burnett
Keyword(s):  
Physical Environment ◽  
Host Selection ◽  
Parasite Species ◽  
Insect Pests ◽  
Host Density ◽  
Host Population ◽  
Average Density ◽  
General Consideration ◽  
Encarsia Formosa ◽  
Host Parasite

That insect parasites regulate and, in the case of newly introduced species, sometimes reduce the average density of insect pests has led to an exmination of the properties of parasites in general. Consideration has been given to the manner in which parasites select hosts for oviposition and to the physiological and psychological basis of this selection. The distribution of parasite progeny among suitable hosts has been analysed in many cases, for the fewer the hostS that are superparasitized for any given number of parasite eggs laid the greater the efficiency of the parasite in reducing host density. It is obvious that before the factors of host selection and superparasitism become important in host-parasite interaction the parasite must find the host individuals. When the hosts are confined to a relatively small area the potential oviposition of the parasite, subject to discrimination among hosts and restraint in oviposition, often determines the level of parasitism. As distance between individuals of the host population becomes greater, however, it is necessary for the parasite to search the environment more extensively. Therefore, the ability of the parasite to find hosts is a factor of prime importance in determining its influence on the density of its host. The success with which a parasite discovers hosts in relation to host density is determined, of course, by several characteristics of the parasite species and by the modification of these characteristics through variations in the physical environment.

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