Comparative electrophoretic profile of proteins and esterases in healthy silkworm larvae ( Bombyx mori Lineu, 1758) and infected with nucleopolyhedrovirus

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.

Download Full-text

Effect of Antibiotics on the Haemocyte Count and Rearing Performance of Silkworm Bombyx mori L.

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2020/v39i4831274 ◽

2020 ◽

pp. 528-538

Author(s):

Iqra Rafiq ◽

Z. I. Buhroo ◽

K. A. Sahaf ◽

N. A. Ganie ◽

M. F. Baqual ◽

...

Keyword(s):

Bombyx Mori ◽

Economic Traits ◽

Silkworm Larvae ◽

Mulberry Leaves ◽

Survival Percentage ◽

Bombyx Mori L ◽

Ceftiofur Sodium ◽

Antibiotic Agents ◽

Silkworm Bombyx Mori ◽

Total Haemocyte Count

Background: Antibiotic agents have been used in recent years to increase the growth of silkworm larvae and to improve production. In this context, the present investigation reported the effects of ceftiofur sodium, oxytetracycline and enroflaxcin on total haemocyte count (cells/mm3), survival percentage and economic characteristics in silkworm Bombyx mori L. at various concentration levels. The study regarding the effect of antibiotics was conducted on the silkworm breed APS-45. Three concentrations (0.05%, 0.10% and 0.15%) were prepared for each antibiotic. The worms were reared upto 3rd instar without any treatment. After third moult silkworms were supplemented with antibiotic fortified mulberry leaves. Results: The experimental results showed that the effect of different antibiotics on economic parameters like larval weight, larval duration, cocoon weight, shell ratio and raw silk percentage were significantly increased in the treated lines in comparison to the control. Antibiotics also increased survival percentage and the most effective result was obtained at 0.15% of ceftiofur sodium followed by oxytetracycline and enroflaxcin. In the present study highest THC value of 9157.33 mm/cm3 was recorded in treatment ceftiofur sodium treated batch at concentration C3 0.15%. An increment in the total haemocyte count was observed in other treatments as well and the cell count increased with an increase in concentration of antibiotic dosage and the effectiveness of the antibiotics followed the order ceftiofur sodium, oxytetracycline and enroflaxcin. Conclusion: This research outlines that there is a significant improvement in the total haemocyte count and economic traits in silkworm with the supplementation of antibiotic fortified mulberry leaves. The antibiotic treatment has significantly improved the raw silk percentage and has been found to be effective in reducing the mortality of silkworms. So, this antibiotic fortification can be further exploited for higher raw silk production.

Download Full-text

Food Selection by Silkworm Larvæ, Bombyx Mori : β-Sitosterol as one of the Biting Factors

Nature ◽

10.1038/190880a0 ◽

1961 ◽

Vol 190 (4779) ◽

pp. 880-881 ◽

Cited By ~ 36

Author(s):

YASUJI HAMAMURA ◽

KEIZO HAYASHIYA ◽

KEN-ICHI NAITO

Keyword(s):

Bombyx Mori ◽

Food Selection ◽

Silkworm Larvae

Download Full-text

Antibody Production in Silkworm Cells and Silkworm Larvae Infected with a Dual Recombinant Bombyx Mori Nuclear Polyhedrosis Virus

Nature Biotechnology ◽

10.1038/nbt0892-910 ◽

1992 ◽

Vol 10 (8) ◽

pp. 910-912 ◽

Cited By ~ 22

Author(s):

Ulrich Reis ◽

Barbara Blum ◽

Bernd-Ulrich von Specht ◽

Horst Domdey ◽

John Collins

Keyword(s):

Bombyx Mori ◽

Antibody Production ◽

Nuclear Polyhedrosis Virus ◽

Silkworm Larvae ◽

Polyhedrosis Virus ◽

Nuclear Polyhedrosis

Download Full-text

Effects of Pyriproxyfen Exposure on Reproduction and Gene Expressions in Silkworm, Bombyx mori

Insects ◽

10.3390/insects11080467 ◽

2020 ◽

Vol 11 (8) ◽

pp. 467

Author(s):

He-Ying Qian ◽

Xiao Zhang ◽

Guo-Dong Zhao ◽

Hui-Min Guo ◽

Gang Li ◽

...

Keyword(s):

Bombyx Mori ◽

Model Organism ◽

Ovary Development ◽

Control Group ◽

Hatching Rate ◽

Hormone Regulation ◽

Concentration Effects ◽

Gene Expressions ◽

Silkworm Larvae ◽

Silkworm Bombyx Mori

The silkworm, Bombyx mori Linnaeus, is an important economic insect and a representative model organism of Lepidoptera, which has been widely used in the study of reproduction and development. The development of the silkworm’s reproductive gland is easily affected by many external factors, such as chemical insecticides. After the silkworm larvae were treated with different concentrations of pyriproxyfen, the results showed that the number of eggs and hatching rate of eggs in the silkworm can be reduced by pyriproxyfen, and the concentration effects were displayed. Pyriproxyfen exposure could affect the normal development of the ovary tissue by reducing the number of oocytes and oogonia in the ovaries of silkworm fed with pyriproxyfen. We employed qRT-PCR, to detect the expressions of genes related to ovary development (Vg, Ovo, Otu, Sxl-S and Sxl-L) and hormone regulation (EcR and JHBP2) in silkworm. Our study showed that the transcription levels of Vg, Ovo, Otu, Sxl-S and Sxl-L in the treatment group were lower than those in the control group (6.08%, 61.99%, 83.51%, 99.31% and 71.95%, respectively). The transcription level of ECR was 70.22% for the control group, while that of JHBP2 was upregulated by 3.92-fold. Changes of transcription levels of these genes caused by pyriproxyfen exposure ultimately affect the absorption of nutrients, energy metabolism, ovary development and egg formation of the silkworm, thus leading to reproductive disorders of the silkworm. In general, our study revealed the response of silkworm reproduction to pyriproxyfen exposure and provided a certain reference value for the metabolism of the silkworm to pyriproxyfen.

Download Full-text

GENERAL CHARACTERISTICS OF CERTAIN INSECT PATHOGENS RELATED TO BACILLUS CEREUS

Canadian Journal of Microbiology ◽

10.1139/m56-016 ◽

1956 ◽

Vol 2 (2) ◽

pp. 111-121 ◽

Cited By ~ 20

Author(s):

T. A. Angus

Keyword(s):

Bacillus Thuringiensis ◽

Bacillus Cereus ◽

Bombyx Mori ◽

North American ◽

Quantitative Difference ◽

Silkworm Larvae ◽

Insect Pathogens ◽

Bombyx Mori L ◽

Morphological Differences ◽

Sporulated Culture

The insect pathogens Bacillus sotto Ishiwata and Bacillus thuringiensis Berliner can be differentiated by means of certain cultural and morphological differences, and by a quantitative difference in pathogenicity for the larvae of Bombyx mori L., B. sotto being the more pathogenic. They are also pathogenic for the larvae of several North American Lepidoptera including Anisota rubicunda (F.), Anisota senatoria (A. and S.), Nymphalis antiopa (L.), Erannis tiliaria (Harr.), Datana integerrima (G. and R.), Datana ministra (Drury), Liparis dispar L., Protoparce quinquemaculata (Haw.), and Protoparce sexta (Johan.). Silkworm larvae ingesting material from a sporulated culture of B. sotto become sluggish, cease feeding, and suffer from a progressive paralysis that begins in the mid-gut area, spreads to affect the whole larva, and ends in death.

Download Full-text

Infection of silkworm larvae by the entomopathogenic fungus Metarhizium anisopliae

Ciência Rural ◽

10.1590/0103-8478cr20151485 ◽

2017 ◽

Vol 47 (4) ◽

Author(s):

Lucineia de Fátima Chasko Ribeiro ◽

Jeronimo Tavares ◽

Sóstenez Alexandre Vessaro Silva ◽

Luis Francisco Angeli Alvez ◽

Eduardo Alexandre Loth ◽

...

Keyword(s):

Fungal Infection ◽

Bombyx Mori ◽

Metarhizium Anisopliae ◽

Entomopathogenic Fungus ◽

Biological Effect ◽

Silkworm Larvae ◽

Large Numbers

ABSTRACT: The isolate E9 of Metarhizium anisopliae was used in commercial hybrids of Bombyx mori larvae to evaluate its biological effect. Symptomatological analyses showed typical signs of fungal infection. Histopathology revealed the presence of large numbers of hemocytes in the hemocoel, and on the sixth dpi the bodies of the insects appeared to be colonised by the fungus. The isolate E9 is pathogenic to larvae B. mori and; therefore, death of the insects was caused by the colonization of fungus in the epidermal and mesodermal tissues.

Download Full-text

Ivermectin modulation of pH-sensitive chloride channels in the silkworm larvae of Bombyx mori

Pesticide Biochemistry and Physiology ◽

10.1016/j.pestbp.2015.08.004 ◽

2016 ◽

Vol 126 ◽

pp. 1-5 ◽

Cited By ~ 7

Author(s):

Yuri Nakatani ◽

Shogo Furutani ◽

Makoto Ihara ◽

Kazuhiko Matsuda

Keyword(s):

Bombyx Mori ◽

Chloride Channels ◽

Ph Sensitive ◽

Silkworm Larvae

Download Full-text

An Effect of Bacillus sotto on the Larvae of Bombyx mori

The Canadian Entomologist ◽

10.4039/ent88138-3 ◽

1956 ◽

Vol 88 (3) ◽

pp. 138-139 ◽

Cited By ~ 19

Author(s):

T. A. Angus ◽

A. M. Heimpel

Keyword(s):

Bombyx Mori ◽

Mode Of Action ◽

Egg Mass ◽

Silkworm Larvae ◽

Toxic Protein ◽

Blood Ph

The paralysis of silkworm larvae (Bombyx mori L.) caused by Bacillus sotto Ishiwata and the extraction of a toxic protein from cultures of this microorganism have been reported elsewhere (1, 2, 3). In preliminary studies of the mode of action, changes have been noted in the pH of the blood of affected larvae.Fourth- and fifth-instar larvae were fed foliage coated with B. sotto toxin and at intervals the blood pH was determined as described by Heimpel (4). Control larvae, reared from the same egg mass, were fed untreated foliage.

Download Full-text