A shared genetic mechanism for melanotic encapsulation of CM-Sephadex beads and a malaria parasite, Plasmodium cynomolgi B, in the mosquito, Anopheles gambiae.
A Plasmodium-refractory strain of Anopheles gambiae that melanizes ookinetes and intrathoracically inoculated CM-Sephadex beads was mated to a Plasmodium-susceptible strain that does not melanize the parasite or the beads. The F1 progeny were then backcrossed to the susceptible strain. Backcross progeny were given a blood meal containing infective Plasmodium cynomolgi B, and the parasites were allowed to develop for 6-7 days, at which time the infected mosquitoes were injected with CM-Sephadex beads. The next day the mosquitoes were dissected and the beads were scored for degree of melanization while the parasites were scored for degree of encapsulation. A Spearman rank order correlation test of the degree of correlation between the bead melanization phenotype and the parasite encapsulation phenotype gave a correlation coefficient of 0.74 (P < 0.01). This strong correlation between the two melanization responses suggests that the mechanisms for differential bead and parasite melanization of these two mosquito strains share at least one major gene.
Gorman
M J
MJ
Entomology Department, University of Wisconsin, Madison 53706, USA.
Cornel
A J
AJ
Collins
F H
FH
Paskewitz
S M
SM
D000818:Animals; D000852:Anopheles / Q000235:genetics* / Q000378:metabolism / Q000469:parasitology; D003433:Crosses, Genetic; D005260:Female; D007303:Insect Vectors / Q000235:genetics* / Q000378:metabolism / Q000469:parasitology; D008297:Male; D008543:Melanins / Q000378:metabolism*; D008863:Microspheres; D010641:Phenotype; D010865:Pilot Projects; D016789:Plasmodium cynomolgi / Q000378:metabolism*
D008543:Melanins