Changes in H+-translocating vacuolar-type ATPase in the anterior silk gland cell of Bombyx mori during metamorphosis.

1998 ◽  
Vol 201 (4) ◽  
pp. 479-486
Author(s):  
M Azuma ◽  
Y Ohta
Keyword(s):  
Bombyx Mori ◽  
Gland Cell ◽  
Specific Inhibitor ◽  
Instar Larva ◽  
Silk Gland ◽  
Ultrastructural Changes ◽  
Immunocytochemical Staining ◽  
Apical Plasma Membrane ◽  
Apical Surface ◽  
Silkworm Larvae

A proton-translocating vacuolar-type ATPase (V-ATPase) was identified and characterized in the anterior silk gland of Bombyx mori. By incubating the intact tissue with the fluorescent dye Acridine Orange, the acidified compartment was detected at the apical pole of the epithelial cells. This was observed throughout the feeding period of the fifth-instar larva until the onset of spinning. Acidification was prevented completely and reversibly by 0.8 micromol l-1 bafilomycin A1, a specific inhibitor of V-ATPase. The presence of V-ATPase in a microsomal fraction was verified by immunoblots using an antiserum to the V-ATPase holoenzyme from Manduca sexta midgut. The antiserum localized the V-ATPase to the apical plasma membrane of the anterior silk gland cells, suggesting that the enzyme is functionally active in pumping protons out of the cell towards the glandular lumen of feeding silkworm larvae. In spinning larvae, the acidification produced by the V-ATPase appears to cease, because acidic compartments were seen rarely and only in the periphery of basal cytoplasm, and because immunocytochemical staining for the V-ATPase was greatly reduced at the apical surface. The metamorphic changes in relation to the occurrence of V-ATPase corresponded well with the ultrastructural changes in the anterior silk gland cell of Bombyx mori larvae.

scholarly journals Nephrotoxic Effects of Paraoxon in Three Rat Models of Acute Intoxication

2021 ◽  
Vol 22 (24) ◽  
pp. 13625
Author(s):  
Vladislav E. Sobolev ◽  
Margarita O. Sokolova ◽  
Richard O. Jenkins ◽  
Nikolay V. Goncharov
Keyword(s):  
Specific Inhibitor ◽  
Acute Poisoning ◽  
Acute Intoxication ◽  
Ultrastructural Changes ◽  
Apical Surface ◽  
Delayed Effects ◽  
Specific Effects ◽  
Nitrophenyl Phosphate ◽  
Species Characteristics ◽  
Distal Tubules

The delayed effects of acute intoxication by organophosphates (OPs) are poorly understood, and the various experimental animal models often do not take into account species characteristics. The principal biochemical feature of rodents is the presence of carboxylesterase in blood plasma, which is a target for OPs and can greatly distort their specific effects. The present study was designed to investigate the nephrotoxic effects of paraoxon (O,O-diethyl O-(4-nitrophenyl) phosphate, POX) using three models of acute poisoning in outbred Wistar rats. In the first model (M1, POX2x group), POX was administered twice at doses 110 µg/kg and 130 µg/kg subcutaneously, with an interval of 1 h. In the second model (M2, CBPOX group), 1 h prior to POX poisoning at a dose of 130 µg/kg subcutaneously, carboxylesterase activity was pre-inhibited by administration of specific inhibitor cresylbenzodioxaphosphorin oxide (CBDP, 3.3 mg/kg intraperitoneally). In the third model (M3), POX was administered subcutaneously just once at doses of LD16 (241 µg/kg), LD50 (250 µg/kg), and LD84 (259 µg/kg). Animal observation and sampling were performed 1, 3, and 7 days after the exposure. Endogenous creatinine clearance (ECC) decreased in 24 h in the POX2x group (p = 0.011). Glucosuria was observed in rats 24 h after exposure to POX in both M1 and M2 models. After 3 days, an increase in urinary excretion of chondroitin sulfate (CS, p = 0.024) and calbindin (p = 0.006) was observed in rats of the CBPOX group. Morphometric analysis revealed a number of differences most significant for rats in the CBPOX group. Furthermore, there was an increase in the area of the renal corpuscles (p = 0.0006), an increase in the diameter of the lumen of the proximal convoluted tubules (PCT, p = 0.0006), and narrowing of the diameter of the distal tubules (p = 0.001). After 7 days, the diameter of the PCT lumen was still increased in the nephrons of the CBPOX group (p = 0.0009). In the M3 model, histopathological and ultrastructural changes in the kidneys were revealed after the exposure to POX at doses of LD50 and LD84. Over a period from 24 h to 3 days, a significant (p = 0.018) expansion of Bowman’s capsule was observed in the kidneys of rats of both the LD50 and LD84 groups. In the epithelium of the proximal tubules, stretching of the basal labyrinth, pycnotic nuclei, and desquamation of microvilli on the apical surface were revealed. In the epithelium of the distal tubules, partial swelling and destruction of mitochondria and pycnotic nuclei was observed, and nuclei were displaced towards the apical surface of cells. After 7 days of the exposure to POX, an increase in the thickness of the glomerular basement membrane (GBM) was observed in the LD50 and LD84 groups (p = 0.019 and 0.026, respectively). Moreover, signs of damage to tubular epithelial cells persisted with blockage of the tubule lumen by cellular detritus and local destruction of the surface of apical cells. Comparison of results from the three models demonstrates that the nephrotoxic effects of POX, evaluated at 1 and 3 days, appear regardless of prior inhibition of carboxylesterase activity.

scholarly journals Estrogen-Related Receptor Influences the Hemolymph Glucose Content by Regulating Midgut Trehalase Gene Expression in the Last Instar Larvae of Bombyx mori

2021 ◽  
Vol 22 (9) ◽  
pp. 4343
Author(s):  
Guanwang Shen ◽  
Jinxin Wu ◽  
Ying Lin ◽  
Xiaoting Hua ◽  
Qingyou Xia ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Silk Gland ◽  
Strongly Correlated ◽  
Cell Level ◽  
Silkworm Larvae ◽  
Glucose Content ◽  
Trehalose Metabolism ◽  
The Relationship ◽  
Glucose Supply ◽  
Estrogen Related Receptor

The expression of trehalase in the midgut of insects plays an important role in glucose supply to the hemolymph. Energy metabolism is usually regulated by the estrogen-related receptor (ERR). A decrease in ATP levels is caused by the ERR hindering glycolysis. However, the relationship between trehalose accumulation and ERR expression is still unclear. Here, we found that silkworm ERR (BmERR) is concentrated and BmERR expression is strongly correlated with trehalase in the midgut during the last instar silkworm larval stage. We cloned the promoter of the trehalase from Bombyx mori (BmTreh) and found that the ERR bound directly to the core response elements of the promoter. Cell level interference and the overexpression of ERR can reduce or enhance BmTreh transcription and promoter activity. Overexpressed transgenic BmERR can significantly increase the expression of BmTreh in the midgut of the last instar silkworm larvae, thereby hydrolyzing trehalose into glucose and releasing it into the hemolymph. Additionally, increased hemolymph glucose content reduces silkworm pupa weight but does not affect silk protein production from the silk gland. Our results suggest a novel function for BmERR through its involvement in BmTreh regulation and expand the understanding of ERR functions in insect trehalose metabolism.

scholarly journals Larval growth, silk production and economic traits of Bombyx mori under the influence of honey-enriched mulberry diet

2015 ◽  
Vol 7 (1) ◽  
pp. 286-292 ◽  
Author(s):  
N. Thulasi ◽  
S. Sivaprasad
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Bombyx Mori ◽  
Larval Growth ◽  
Silk Gland ◽  
Economic Traits ◽  
Silkworm Larvae ◽  
Shell Weight ◽  
Shell Protein ◽  
The Impact

The impact of honey on the silkworm, Bombyx mori was demonstrated with reference to the larval growth, silk gland proteins and economic parameters of sericulture. The honey works well at a concentration of 2% in distilled water. At this concentration it promotes growth rates in the silkworm larvae during fifth instar development. It positively reinforces the day-to-day larval growth rate by 4.75 additional percentile points, silk gland growth rate by 4.45 additional percentile points and the gland-body ratio by additional 6.64 percentile points. It stimulates silk protein synthesis in all the three segments of the silk gland, viz., the anterior, middle and posterior parts. Under its influence, the silk gland protein profiles grew significantly by 14.85 additional percentile points in the anterior silk gland (ASG), minimally by 8.68 additional percentile points in the middle silk gland (MSG) and maximally by 15.17 additional percentile points in the posterior silk gland (MSG), compared to their control values. It also stimulates the core shell protein synthesis by 18% and retards floss protein synthesis by ~25% in the three segments of silk gland. In doing so, it contributes to sericulture industry by causing improvements in profit making economic traits such as gland-body ratio, cocoon weight, shell weight, raw silk weight, denier and renditta and by reducing the production of floss, which contributes to loss in the sericulture industry. Honey is suggested as a profitable supplementary diet forsilkworm.

scholarly journals STUDIES ON THE POSTERIOR SILK GLAND OF THE SILKWORM, BOMBYX MORI

1968 ◽  
Vol 38 (3) ◽  
pp. 589-603 ◽  
Author(s):  
Shiro Matsuura ◽  
Takashi Morimoto ◽  
Sunao Nagata ◽  
Yutaka Tashiro
Keyword(s):  
Bombyx Mori ◽  
Silk Gland ◽  
Ultrastructural Changes ◽  
Prepupal Stage ◽  
Smooth Membrane ◽  
Wet Weight ◽  
Rough Er ◽  
Silkworm Bombyx Mori ◽  
Myelin Figures ◽  
Posterior Silk Gland

Cytolytic processes in posterior silk gland cells of the silkworm, Bombyx mori, during metamorphosis from larva to pupa have been studied. During this stage, the wet weight and the amounts of RNA and protein of the gland decrease rapidly and markedly, while the amount of DNA decreases slowly and slightly. The ultrastructural changes observed at the beginning of the prepupal stage consist of the appearance or the increase in the number of autophagosomes containing endoplasmic reticulum (ER), or "early autophagosomes" as we have called them, which seem to be gradually transformed to autolysosomes. A number of usual lysosomes, which frequently contain myelin figures, also appear in the cytoplasm. Sometimes they fuse with each other to form large conglomerates. In the middle of the prepupal stage, a number of smooth membrane-bounded vacuoles appear in cytoplasm. Towards the end of the prepupal stage the partition or sequestration of cytoplasm was observed. Thus large autophagosomes containing cytoplasmic organelles such as rough ER and/or mitochondria are formed. The nucleus is partitioned in a similar way by smooth membranes, and then autophagosomes containing condensed chromatin blocks are formed. These various kinds of autophagosomes, or "late autophagosomes" as we have generally called them, are continuously released into the hemolymph until the gland is completely disintegrated.

scholarly journals Quantitative Profile Analysis of Mulberry Silkworm Bombyx mori L. (CSR2XCSR4)

2015 ◽  
Vol 34 ◽  
pp. 34-41 ◽  
Author(s):  
B. Venugopal Reddy ◽  
P. Divya ◽  
M. Anitha
Keyword(s):  
Bombyx Mori ◽  
Protein Concentration ◽  
Profile Analysis ◽  
Quantitative Estimation ◽  
Silk Gland ◽  
Silkworm Larvae ◽  
Silk Production ◽  
Silk Worm ◽  
Bombyx Mori L ◽  
Mulberry Silkworm

Bombyx mori. L. (CSR2XCSR4) is a bivolitne crossbreed that produces high quantity of silk. The weights of worms and glands are directly related to the yield of silk, higher larval weights leads to higher silk production. In the present study, quantitative parameters of 5th instar and pupal stages of silkworm larvae were observed. The analysis of quantitative estimation showed that the maximum weights and lengths of silk gland and silk worm were recorded on 7th day of 5th instar larval stage. The day dependent variation in protein concentration was observed in total silk gland 5th instar larval and pupal stages.

Establishment and Gene Expression Characteristics of the Silk Gland Cell Line BmSG-SWU1 of Bombyx mori (Lepidoptera: Bombycidae)

2014 ◽  
Vol 107 (5) ◽  
pp. 1018-1026
Author(s):  
Zhen-Yue Feng ◽  
Chun Pan ◽  
Min Liu ◽  
Zhi-Qiang Tian ◽  
Xue-Mei Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bombyx Mori ◽  
Cell Line ◽  
Gland Cell ◽  
Silk Gland ◽  
Expression Characteristics

Role of Bm30kc6 gene in cell apoptosis and the silk gland degradation signaling pathway in Bombyx mori L.

2020 ◽  
Vol 105 (3) ◽  
Author(s):  
Ying Xiao ◽  
Lei‐lei Li ◽  
Asma Bibi ◽  
Ning Zhang ◽  
Ting Chen ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Silk Gland ◽  
Bombyx Mori L

Sage controls silk gland development by regulating Dfd in Bombyx mori

2021 ◽  
pp. 103568
Author(s):  
Sihan Hou ◽  
Cuicui Tao ◽  
Hongguo Yang ◽  
Tingcai Cheng ◽  
Chun Liu
Keyword(s):  
Bombyx Mori ◽  
Silk Gland ◽  
Gland Development
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