Host-parasite system

Prey-predator or host-parasite systems can oe analyzed by mass balance equations ... 

Desdevises, Y., Morand, S., Jousson, O. and Legendre, P. (2002) Coevolution between Lamellodiscus (Monogenea Diplectanidae) and Sparidae (Teleostei) the study of a complex host-parasite system. Evolution 56, 2459-2471. 

The immunobiology of this family has been reviewed by Hopkins (332) and Ito Smyth (353), the species most studied being Hymenolepis diminuta, H. nana, H. microstoma, and H. citelli, in that order. Much of the experimental work has been carried out on what must be considered to be artificial host-parasite systems, i.e. those not occurring naturally. As discussed below, H. diminuta grows readily in rats (Fig. 11.5) but in the mouse host it develops to some extent and is then rejected without reaching maturity. In these... 

Hoberg, E.P. and Brooks, D.R. (2008) A macroevolutionary mosaic Episodic host-switching, geographical colonization and diversification in complex host-parasite systems. Journal of Biogeography, 35 1533-1550. 

A combination of combustion calorimetry and respiration rate determination was used to establish an energy balance for an aquatic host-parasite system [122] the three-spined stickleback Gasterosteus aculeatus infected by the pseudophyl-... 

The third example considered the interaction of life-history traits (survival rates, fecundity, immunogenicity) with an environmental factor specific to parasites, namely the host immune system. Here phenotypic diversity in response to environmental conditions (host immunity) is not so readily apparent. To observe phenotypic diversity, different parasite lines need to be compared in their kinetics of infection and, to show immune-dependence, these must be complemented by control experiments in immunosuppressed hosts. Experiments seeking to select on this diversity... 

In the general spectrum of host-parasite relationships, there is considerable parasite-induced host variability resulting in perturbed host physiology, biochemistry, and developmental behavior (8, 21, 22). There is a wide range of speculation that the parasite has the capacity to modulate or regulate host systems (8, 10, 23). It is clear that the C. sonorensis polydnavirus induces developmental arrest in H. virescens larva (18, 24,... 

One likely reason for the prevalence of helminths is their undoubted ability to down-regulate the host immune system at both the antigen-specific and polyclonal levels [3], In many chronic diseases, such as schistosomiasis and lymphatic filariasis, peripheral blood T cells show dramatically impaired parasite antigen-specific responsiveness [4], as discussed in more detail below. Moreover, from early reports of immunosuppression in animal models of infection, to studies in Africa linking vaccine failure to heavy helminth infection, there is clear evidence that infections can diminish reactivity to bystander antigens, particularly with increasing intensity of... 

African sleeping sickness, or African trypanosomiasis, is caused by protists (single-celled eukaryotes) called trypanosomes (Fig. 1). This disease (and related trypanosome-caused diseases) is medically and economically significant in many developing nations. Until recently, the disease was virtually incurable. Vaccines are ineffective, because the parasite has a novel mechanism to evade the host immune system. 

Coevolution nSSU Host-parasite cospeciation not typical in a monogenean/ marine fish system Desdevises et al. (2002)... 

Flatworm parasites are well recognized for their ability to live for decades in environments where they are in contact with potentially damaging immune factors. This adaptability reflects the fact that these parasites have evolved mechanisms to evade immune effector mechanisms, and more remarkably, to sense and utilize components of the host immune system for their own development. Schistosomes, digenetic trematodes, are undoubtedly the most well-studied parasitic flatworms. These parasites infect over 200 million people in tropical and subtropical zones, and cause severe disease in approximately 5% of those infected. Of immunological interest is the fact that pathology in schistosome-infected individuals is caused largely by the immune response... 

Previous results have shown that parasite infection of the snail host affects the neuroendocrine system of the snail in a way that results in reduced reproduction of these snails a phenomenon referred to as parasitic castration (Crews and Yoshino 1989 Sorensen and Minchella, 2001). The Lymnaea stagnalis-Trichobilharzia ocellata host-parasite combination has been the model system adopted for most of these studies (de Jong-Brink et at., 2001). However, comparable studies as to how parasite infection affects the snail s central nervous system (CNS) in releasing neuropeptides and bioamines that modulate snail reproduction and the internal defence system of... 

Turillazzi S., Sledge M. F., Dani F. R., Cervo R., Massolo A. and Fondelli L. (2000) Social hackers integration in the host recognition system by a paper wasp social parasite. Naturwissenschaften 87, 172-176. 

One fascinating aspect of hydrocarbon evolution as semiochemicals lies in the documented chemical mimicry systems between parasite and host (Chapter 14, this book). Some systems operate by camouflage and passive transport, others by loss of parasite specific compounds, some use de novo synthesis of the same host mixture or part of the mixture, and others are as yet unrevealed. To date we are mostly limited to the description of the host-parasite chemical coevolution (or arms race), but we hope in the near future to be able to associate biosynthetic pathways as well as gene expression with such evolutionary processes. 

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