INVIVO NEGATIVE STAINING OF THE MIDGUT CONTINUOUS JUNCTION IN THE MOSQUITO, CULEX-TARSALIS (DIPTERA, CULICIDAE)

  • 1 January 1979
    • journal article
    • research article
    • Vol. 36  (3) , 267-275
Abstract
The midguts of female mosquitoes, C. tarsalis, were examined by EM during the digestion of a meal from either artificial sources (i.e., 100% serum or defibrinated rabbit blood) or vertebrate hosts. Intense intercellular staining was apparent when the meal was derived from the vertebrate host or defibrinated rabbit blood and less intense staining with 100% serum. The staining was attributed to the leakage of a component of whole blood, presumably Hb, into the intercellular junctional spaces. The staining component demonstrated an affinity for the outer membrane leaflet of the plasma membrane. Leaky guts may be a means of infecting an arthropod host without a midgut amplification cycle. The ramifications are pointed out with reference to vector competence and midgut barriers to infection by arboviruses.