Nutrient digestion and absorption after blood feeding are important events for Lutzomyia longipalpis, which uses these nutrients to produce eggs. In this context, the pH inside the digestive tract is an important physiological feature as it can markedly influence the digestive process as well as interfere with Leishmania development in infected phlebotomines. It was described previously that un...

The permeability of the midgut of the fleshfly, Sarcophagafalculata, to the orally toxic polypeptide (Mr~7000), a cobra venom-cardiotoxin, was investigated by LM and EM autoradiography, using the radio-iodinated toxin. The histology of the normal and toxin affected midgut was also investigated. 1. The midgut could be classified into segments that were permeable, partially-permeable and non-perm...

The presence of bacteria in the midgut of mosquitoes antagonizes infectious agents, such as Dengue and Plasmodium, acting as a negative factor in the vectorial competence of the mosquito. Therefore, knowledge of the molecular mechanisms involved in the control of midgut microbiota could help in the development of new tools to reduce transmission. We hypothesized that toxic reactive oxygen speci...

The number of insect midgut cells is maintained homeostatically in vivo and in vitro. However, during starvation, the midgut shrinks and the rate of cell replacement appears to be suppressed. When they undergo metamorphosis, the internal organs of insects are drastically remodeled by cell proliferation, differentiation, and apoptotic processes, and the net number of cells usually increases. An ...

1. The 28Mg-measured net flux of magnesium from lumen-side to haemolymph-side of the isolated and short-circuited midgut was 1.97 +/- 0.28 mu-equiv cm(-2) /(-1) in 8 mM-Mg2+. 2. The magnesium-influx shows a delay before the tracer steady-state is attained, indicating the existence of a magnesium-transport pool equivalent to 6.7 mu-equiv/g wet weight of midgut tissue. 3. Magnesium depresses the ...

The honey bee has been regarded as a key species in the environmental risk assessment of biotech crops. Here, the potential adverse effects of Cry1Ie toxin on the midgut bacteria of the worker bees (Apis mellifera ligustica) were investigated under laboratory conditions. Newly emerged bees were fed with different concentrations of Cry1Ie toxin syrups (20 ng/mL, 200 ng/mL, and 20 μg/mL), pure su...

Six 3D models of the digestive system during ontogeny were reconstructed from histological sections of Atlantic cod larvae. The 3D models clearly visualize the following features: folding of the gut rotation; subdivision of digestive tract into foregut, midgut, and hindgut by sphincters; development of stomach and pyloric caeca from 39 dph; location of entrances of bile and pancreatic ducts in ...

The mosquito Aedes taeniorhynchus is an important epidemic vector of Venezuelan equine encephalitis virus (VEEV), but detailed studies of its infection are lacking. We compared infection by an epidemic VEEV strain to that by an enzootic strain using virus titrations, immunohistochemistry, and a virus expressing the green fluorescent protein. Ae. taeniorhynchus was more susceptible to the epidem...

Resistance to Cry toxins can develop by alterations in any of the steps in the Cry toxin mode of action. Most characterized mechanisms of resistance to Cry toxins involve alterations in enzymatic toxin processing or toxin interaction with receptors in the insect midgut epithelium. Previous reports have suggested an alternative mechanism of resistance to Cry1Ac toxin in Heliothis virescens larva...

Abnormalities in midgut rotation occur during the physiological herniation of the midgut between the 5th and 10th week of gestation. The most significant abnormality is a narrow small bowel mesentery which is prone to volvulus. This occurs most frequently in the neonatal period. Less commonly, midgut malrotation presents in adulthood with either acute volvulus or chronic abdominal symptoms. It ...