• Applied Microscopy
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• v.34 no.3
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• pp.199-209
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• 2004

The migut epitheluim of the last instar larva in the mosquito larvae, Anopheles sinensis was observed with electron microscopes. The midgut epitheluim of the mosquito larva is composed of a single-layered columnar absorptive cells, regenerative cells and secretory granular cells. The free surface of the columnar absorptive cells has a regular array of microvilli 'brush border', while cell membranes close to the basal lamina are extrmely infolded and a lot of mitochondria are concentrated in those processes. The columnar absorptive cells also contain cell organelles expected to be found in absorptive cell. Midgut regenerative cells which are positioned basally in the epithelium form the groups, which are called 'nidi', composed of 1 or $2{\sim}3$ cells, they show darker appearance than the columnar absoptive cells. The secretory granular cells contain numerous electron dense granules, $200{\sim}400$ nm in diameter. The cone shaped secretory granular cells are located in the basal portion of the midgut epitheluim. The epithelium is surrounded by the subepithelial space and muscle bundles. The subepithelial space, which is filled with fibrous connective tissue, is innervated by many axon cells and tracheoles.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.144-144
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• 2003

In order to understand the expression profile of earthworm midgut, we analyzed 1255 expressed sequence tags (ESTs) derived from earthworm midgut cDNA library. Among 1255 ESTs analyzed, 537 (42.8%) ESTs represented 231 unique genes of which 168 ESTs were singletons and 63 ESTs represented by two or more ESTs. A total of 571 unknown ESTs showed no significant homology. The remaining 147 (11.7%) ESTs whose lengths were less than 150 bp were removed. Among 231 identified unique genes, 168 genes (72.7%) were sequenced only once. (omitted)

• BMB Reports
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• v.36 no.5
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• pp.508-513
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• 2003

The bacterium Bacillus thuringiensis produces toxin inclusions that are deleterious to target insect larvae. These toxins are believed to interact with a specific receptor protein(s) that is present on the gut epithelial cells of the larvae. In various insect species (in particular those belonging to the lepidopteran class), aminopeptidase N (APN) is one of the two receptor proteins that are considered to be involved in toxin-receptor interactions. However, in mosquitoes, the nature and identity of the receptor protein is unknown. Here, using RT-PCR, we identified two isoforms of the APN transcripts in the Aedes aegypti mosquito larval midgut. These results are congruent with a previous report of multiple isoforms of the APN gene expression in lepidopteran larvae. Which of the two isoforms (or other yet unidentified receptor proteins) is involved in the killing of mosquito larvae remains to be elucidated.

• Applied Microscopy
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• v.21 no.1
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• pp.21-26
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• 1991

Midgut cells of the dead Dendrolimus spectabilis larvae by infection of D. spectabilis nuclear polyhedrosis virus (DsNPV) were observed by transmission electron microscopy. DsNPV replicated in the nucleus of the infected midgut cells and the virogenic stroma of DsNPV appeared in the nucleus, from which nucleocapsids were formed. Also the formation of polyhedral inclusion bodies were observed in the nucleus.

• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.513-519
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• 1993

The alkaline protease in the polyhedra preparation of Spodoptera litura nuclear polyhedrosis virus was successfully inactivated by heating at 100C for 20 minutes. SDS-PAGE analysis indicated that heat inactivated polyhedra is composed of major proteins of 31kDa and presumptive its polymer protein of 62kDa. However, this polyhedra was converted into several smaller molecular weight proteins when treated with midgut juice, but not by treatment with heat-inactivated midgut juice.

• BMB Reports
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• v.40 no.5
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• pp.783-790
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• 2007

Receptor binding plays an important role in determining host specificity of the Bacillus thuringiensis Cry $\delta$-endotoxins. Mutations in domains II and III have suggested the participation of certain residues in receptor recognition and insect specificity. In the present study, we expressed the cloned domain II-III fragment of Cry4Ba and examined its binding characteristics to mosquito-larval midgut proteins. The 43-kDa Cry4Ba-domain II-III protein over-expressed in Escherichia coli as inclusion bodies was only soluble when carbonate buffer, pH 10.0 was supplemented with 4M urea. After renaturation via stepwise dialysis and subsequent purification, the refolded domain II-III protein, which specifically reacts with anti Cry4Ba-domain III monoclonal antibody, predominantly exists as a $\beta$-sheet structure determined by circular dichroism spectroscopy. In vitro binding analysis to both histological midgut tissue sections and brush border membrane proteins prepared from susceptible Aedes aegypti mosquito-larvae revealed that the isolated Cry4Ba-domain II-III protein showed binding functionality comparable to the 65-kDa full-length active toxin. Altogether, the data present the 43-kDa Cry4Ba fragment comprising domains II and III that was produced in isolation was able to retain its receptor-binding characteristics to the target larval midgut proteins.

• Applied Microscopy
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• v.20 no.1
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• pp.105-119
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• 1990

In order to know the morphological characteristics and changes according to the developmental stage, the comparative observations have been studied by light and electron microscope on the midgut(gastric caecum, stomach) of the grasshopper(Oxya sinuosa Mistshenko). The results obtained are summarized as follow : In light microscopic level, the cuboidal shaped cells of the gastric caecum in the 5th instar nymph are differentiated the columnar epithelium in the adult. A number of pigment granules are appeared in the gastric caecum of the 5th instar nymph, however the pigment granules were absent in the adult. Indistinct or undifferentiated folds of the epithelial layer were appeared in the 5th instar nymph, whereas the well-developed folds were appeared the gastric caecum in the adult. The well-developed muscular layers are seen in the 5th instar numph, however in the adult the muscular layers are appeared thin or a few layers. In electron microscopic level, in the midgut epithelium, a number of well-developed rER, a few lipid droplets, multi vesicular bodies, small vesicles and glycogen granules were found. Two types of the pigment granules in the gastric caecum of the 5th instar nymph were appeared, whereas the whorl-membrane, a few secretory granules and one type of the gastro-entero-endocrine cell were found in the adult midgut. The light and dark cells could be distinguished in the stomach epithelim of the 5th instar nymph.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.5
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• pp.423-429
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• 2020

Purpose: Alimentary tract duplication (ATD) is a rare congenital condition that may occur throughout the intestinal tract. Clinical symptoms are generally related to the involved site, size of duplication, or associated ectopic mucosa. This study aimed to identify clinical implications by anatomical locations and age group and then suggest a relevant management according to its distinct features. Methods: We retrospectively reviewed the clinical data of pediatric patients who received a surgical management due to ATD. Furthermore, data including patients' demographics, anatomical distribution of the duplication, clinical features according to anatomical variants, and outcomes were compared. Results: A total of 25 patients were included in this study. ATD developed most commonly in the midgut, especially at the ileocecal region. The most common clinical presentation was abdominal pain, a sign resulting from intestinal obstruction, gastrointestinal bleeding, and intussusception. The non-communicating cystic type was the most common pathological feature in all age groups. Clinically, prenatal detection was relatively low; however, it usually manifested before the infantile period. A laparoscopic procedure was performed in most cases (18/25, 72.0%), significantly in the midgut lesion (p=0.012). Conclusion: ATD occurs most commonly at the ileocecal region, and a symptomatic one may usually be detected before the early childhood period. Surgical management should be considered whether symptom or not regarding its symptomatic progression, and a minimal invasive procedure is the preferred method, especially for the midgut lesion.

• Korean journal of applied entomology
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• v.32 no.3
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• pp.291-299
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• 1993

Midgut tissues from 4 insect specIes were exammed for the activity of cytochrome P-450 monooxygenases, a major enzyme involved in chemical detoxification. When Helicoverpa assulta larvae were reared on an artificial d;et, the specific activity of the midgut cytochrome P-450 monooxygenases (MFO) was :3 times higher than that of the fat body, The specific activity of the midgut cytochrome P-450 monooxygenases was higher in H. assul/a larvae when reared on Nicotiana tabacum leaves than when on CapsIcum annuum fruits or an artificial diet. In the case of Hyphantria cunea larvae, Tilia megaphyllo leaves were the best in inducing midgut cytochrome P-450 monooxygenases activity. When larvae of H. assulta, Spodoptera exigua, H. cunea and Spodoptera litura were reared on their own artificial diet, the highest activity was seen in S. exigua larvae which is a polyphagous and insecticide-resistant strain.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.2
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• pp.59-64
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• 2011

Protein kinase C (PKC) is involved in many cellular signaling pathways, it participates in many physiological processes, such as cell cycle, growth, proliferation, differentiation and apoptosis. To investigate the effect of PKC on the silkworm midgut tissue infection of Bombyx mori parvo-like virus (BmPLV), a B. mori atypical protein kinase C (BmaPKC) gene was cloned from larval midgut tissue, expressed in E. coli and purified. Additionally, the BmPLV susceptible silkworm strain and resistant silkworm strain were used to test the effect of the B. mori infection on BmPLV. The result showed that BmaPKC encodes a predicted 586 amino acid protein, which contains a C-terminal kinase domain and an N-terminal regulatory domain. The maximum expression amount of the soluble (His)6-tagged fusion protein was detected after 0.8 mmol/L IPTG was added and cultured at $21^{\circ}C$. The (His) 6-tagged fusion protein revealed about 73 kDa molecular weight which confirmed by western blot and mass spectrography. Furthermore BmaPKC protein were detected at 0-72 h post-infection in BmPLVinfected larval midgut tissue, western blot showed that as time went on, the expression of BmaPKC increased gradually in susceptible strain, the expression quantity on 72 h is 5 times of 0 h. However, in resistant strain, the expression quantity is slightly lower than susceptible strain. But no significant change in resistant strain was observed as time went on. The available data suggest that BmaPKC may involve in the regulation of BmPLV proliferation.