The Effects of Parabiotic Twinning of Susceptible and Refractory Mosquitoes on the Development of Plasmodium gallinaceum

Abstract

Two species of mosquitoes were joined parabiotically with glass capillaries so as to share common hemolymph. In experiments designed to determine optimum physical factors was found that capillaries of 2.5 mm in length, 100 microns OD and with pointed ends were tolerated best by mosquitoes and permitted optimum hemolymph transfer. Maximum survival of mosquitoes was noted when capillaries were inserted in the post mesospiracular membranous area, in the largest mosquito first and allowed to fill with hemolymph prior to inserting in the second mosquito. Mosquitoes having blood meals prior to twinning retained capillaries best. Use of CO2 anesthetization and a 30-min holding period while anesthetized contributed to greater survival and union of the mosquitoes. In the principal experiments, designed to study the nature of innate immunity of Culex pipiens to Plasmodium gallinaceum, 243 of 2,126 parabiotic twins of C. pipiens and infected Aedes aegypti survived to be evaluated. None of the C. pipiens became infected and only four A. aegypti remained infected. The controls were 93 to 95% infected. It was concluded that the refractory species possessed substances that were toxic to the parasites and prevented parasite development in both species. If there was a lack of essential substances (that could not be transferred) in the refractory C. pipiens they could have been provided by the highly susceptible A. aegypti and both species would have become infected. Innate immunity is therefore antiblastic not atreptic.

Diptera vectors of avian Haemosporidian parasites: untangling parasite life cycles and their taxonomy

“…It was proven later that the innate immunity of Cx. pipiens mosquitoes to P. gallinaceum infection is due to antagonistic (antiblastic) factors in mosquito haemolymph and not to the lack of metabolites or required substances (Weathersby & McCroddan, 1982). However, it now appears that these innate immunity mechanisms are not generalisable across species.…”

Contribution made by parabiosis to the understanding of energy balance regulation

“…Although a variety of methods have been used to produce a cross-circulation in species such as mosquitoes [15], cockroaches [16], rabbits [17] and dogs [18], this review will focus on the work done with rodents because rats and mice are predominant in both past and present literature on parabiosis.…”

Molecular Genetics of Mosquito Resistance to Malaria Parasites

“…aegypti supported parasite development as compared to about 95% of unjoined Ae. aegypti controls, suggesting that the resistance of C. pipiens was caused by an diffusible toxic humoral factor (Weathersby and McCroddan 1982). Vector-parasite compatibility or its absence may be enforced at multiple steps during parasite development (Alavi et al 2003).…”