Symbiotic viruses

The adult female parasitoid may transfer one or more type(s) of regulatory factor(s) to the host during parasitism. Some genera of braconid and scelionid families produce teratocytes. These cells originate from an embryonic membrane in the parasitoid egg and are released into the host hemocoel. Certain parasitoid females of the families Ichneumonidae and Braconidae contain symbiotic viruses that are injected into the host with the egg. Diverse functions have been attributed to the teratocytes and the symbiotic viruses. Both play a major role in the interaction of the parasitoid with their respective hosts. 

Other developmental effects caused by a symbiotic virus from a parasitoid may involve the nutritional physiology of the host. An increase in trehalose levels in the hemolymph of II. virescens parasitized by M. croceipes could be duplicated by the injection of the calyx fluid from the parasitoid (111). Though there is no known explanation for the increase in trehalose, it is proposed to result from the release of glucose that is catabolized to trehalose in the host (13). An increase in the host hemolymph trehalose level may have a nutritional benefit for M. croceipes which is a hemolymph feeder. 

From this review we see that symbiotic viruses from the braconids and the ichneumonids have some differences in their physical structures and their apparent interaction with the host. Some variations noted in the action of these viruses may eventually be correlated with differences in viral structures and the interaction of the viruses with venom components. Certain host tissues may be susceptible to one virus-type and refractive to the other virus-type. It is possible that ichneumonids, which are commonly known as tissue feeders, contain symbiotic viruses that have a more prominent effect on the endocrine system of the host, thereby preserving the host tissue. In comparison, braconids, which... 

Secretions from Glands and Other Specialized Tissues. In general, parasitic Hymenoptera are known to inject secretions from glands and specialized tissues into their hosts. Those secretions, except for the symbiotic viruses and virus material or calyx fluid, are collectively presented in the next two sections as venomous substances. 

But real systems are usually not simple feedback loops. In a virus such as bacteriophage the decision to kill the infected bacterial cell or to establish a symbiotic association with it depends on complex interactions involving a number of interconnected feedback loops. Such systems (and even simpler ones) would need a formal description in view of their complexity but as a matter of fact this complexity is such that the classical methods are much too heavy. This was a reason for trying a logical description, that is, a description using variables and functions which can take only a limited number of values—typically two (1 and 0). 

Modern life comes in very many forms animals, plants, and single-celled eukaryotes in the Eucarya domain prokaryotes in two great domains, Archea and Bacteria (Woese, 1987 Woese et al, 1990), and not-life viruses. Some not-life is even anthropogenic the wild-type polio virus that used to be found in water bodies is now replaced in the pools and rivers of America and Europe by the altered vaccine-type virus. From all this information, deductions can be made. Clearly, multicelled life came from single-celled life less obviously but most probably each of our cells carries mitochondria that are descended from symbiotic purple bacteria. Plants, in addition, carry chloroplasts that are descended from partner cyanobacteria. 

Nonparalyzing Venoaous Substances. Often the injection of the virus material and nonparalyzing venomous substances occur simultaneously so that the effects are not easily separated. Reference is made in this section to reports where venomous substances were shown to perform a function independent of symbiotic... 

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