proteases play a key role in protein digestion in ticks and other haematophagous insects. our understanding of blood meal digestion in digestive system of ticks can be very useful for better understanding of basic rules for control of ticks. cells of the midgut endocytose blood components. blood proteins uptake by midgut cells, suggesting the presence of proteases in the midgut cells. in this s...

Plasmodium ookinete invasion of the mosquito midgut is a crucial step of the parasite life cycle but little is known about the molecular mechanisms involved. Previously, a phage display peptide library screen identified SM1, a peptide that binds to the mosquito midgut epithelium and inhibits ookinete invasion. SM1 was characterized as a mimotope of an ookinete surface enolase and SM1 presumably...

On the Antarctica continent the wingless midge, Belgica antarctica (Diptera, Chironomidae) occurs further south than any other insect. The digestive tract of the larval stage of Belgica that inhabits this extreme environment and feeds in detritus of penguin rookeries has been described for the first time. Ingested food passes through a foregut lumen and into a stomodeal valve representing an in...

The spectrum of Tenebrio molitor larval digestive proteinases was studied in the context of the spatial organization of protein digestion in the midgut. The pH of midgut contents increased from 5.2-5.6 to 7.8-8.2 from the anterior to the posterior. This pH gradient was reflected in the pH optima of the total proteolytic activity, 5.2 in the anterior and 9.0 in the posterior midgut. When measure...

We have previously demonstrated the involvement of carbonic anhydrase (CA) in larval mosquito midgut physiology. In this study, we used Hansson's histochemistry to examine the distribution of the enzyme in the midgut of Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, Culex nigripalpus, Ochlerotatus taeniorhynchus, Anopheles albimanus and Anopheles quadrimaculatus adult mosquitoes. Addi...

During sporulation, Bacillus thuringiensis produces crystalline inclusions comprised of a mixture of delta-endotoxins. Following ingestion by insect larvae, these inclusion proteins are solubilized, and the protoxins are converted to toxins. These bind specifically to receptors on the surfaces of midgut apical cells and are then incorporated into the membrane to form ion channels. The steps req...

The midgut pH of gypsy moth (Lymantria dispar) larvae was significantly lower when larvae were fed acidic foliage. At 30 min after the start of a feeding bout, larvae feeding on bigtooth aspen (foliage pH = 6.04) had average midgut pH levels of 10.16, while larvae feeding on red oak foliage (foliage pH = 3.84) had average midgut pH levels of 9.36. Midgut pH was also significantly reduced when l...

The Drosophila GATA factor gene serpent (srp) is required for the early differentiation of the anterior and posterior midgut primordia. In particular, srp is sufficient and necessary for the primordial gut cells to undertake an epithelial-to-mesenchimal transition (EMT). Two other GATA factor genes, dGATAe and grain (grn), are also specifically expressed in the midgut. On the one hand, dGATAe e...

a study of insect digestive enzymes makes sense given that the gut is the major interface between the insect and its environment. an understanding of gut and digestive enzyme function is essential when advanced methods of insect management such as application of enzyme inhibitors and transgenic plants are developed to control insect pests. the aim of the current research project was to study mi...