Culex quinquefasciatus and Heliothis virescens synthesize trypsin and chymotryspin like enzymes in their midgut as the major protein digesting enzymes. To study the effect of Trypsin Modulating Oostatic Factor (TMOF) and other factors on midgut serine proteases, the cDNAs of trypsin and chymotrypsin were cloned, sequenced and 3D models built. Injection of TMOF into female Culex quinquefasciatus and Heliothis virescens 3rd instar larvae stopped trypsin biosynthesis in the midgut 24 h later. Similar results were obtained when Culex larvae were fed the hormone. A translational and other control mechanisms of trypsin and chymotrypsin genes in the midgut of adult and larval Culex mosquitoes and larval Heliothis were studied and will be discussed as a possible mechanism to control these insects in the field.
Species 1: Diptera Culicidae Culex quinquefasciatus (southern house mosquito)
Species 2: Lepidoptera Noctuidae Heliothis virescens
Keywords: insect digestion
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