Effects of juvenile hormone, ecdysterone, actinomycin D, and mitomycin C on the cuticular proteins of Tenebrio molitor

Development ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 107-123
Author(s):  
P. Elaine Roberts ◽  
Judith H. Willis
Keyword(s):  
Juvenile Hormone ◽  
Mitomycin C ◽  
Actinomycin D ◽  
Electrophoretic Analysis ◽  
Tenebrio Molitor ◽  
Staining Intensity ◽  
Soluble Proteins ◽  
Blood Proteins ◽  
Intense Staining ◽  
Cuticular Proteins

Juvenile hormone (JH), ecdysterone and some antibiotics cause Tenebrio molitor to form a second pupa or pupal-adult intermediate. Incorporation of labelled leucine into the cuticular proteins of JH-induced second pupae did not differ from incorporation in normal pupae, and the soluble cuticular proteins from these young second pupae were identical to those extracted from normal pupal exocuticle when analysed by SDS-polyacry lamide gel electrophoresis. However, as these second pupae aged, the major early bands did not undergo a normal decrease in staining intensity, indicating a JH effect on protein insolubilization (sclerotization). The transport of protein into the cuticle may also have been altered by JH; electrophoretic analysis of the new cuticle of treated animals showed intense staining of bands with RF'S similar to those of blood proteins. The new exocuticle produced after treatment of pupae with ecdysterone had soluble proteins which were typical of normal pupae, but extracts from such animals aged prior to cuticle removal yielded bands characteristic of normal adults. Pupae treated with actinomycin D occasionally form new abdominal cuticle with characteristic pupal morphology. These cuticles yielded soluble proteins which, upon analysis, had pupal, pupal and adult, or adult banding patterns. Animals treated with mitomycin C, although retaining vestiges of pupal abdominal characters, had adult cuticular proteins.

Electrophoretic analysis of effects of in vitro heating on proteins and enzymes from dormant peanuts (Arachis hypogaea)

1973 ◽  
Vol 51 (6) ◽  
pp. 1191-1196 ◽  
Author(s):  
Dempsey L. Thomas ◽  
James E. Bright
Keyword(s):  
Thermal Sensitivity ◽  
Distribution Patterns ◽  
Electrophoretic Analysis ◽  
Staining Intensity ◽  
Soluble Proteins ◽  
Starch Gel Electrophoresis ◽  
Complete Inactivation ◽  
Reserve Protein ◽  
Different Temperatures

Protein extracts from dormant peanut cotyledons were heated to determine the influence of different temperatures on banding characteristics of soluble proteins and enzymes by use of horizontal starch gel electrophoresis. Soluble proteins showed no significant change between 25° and 85 °C. At 95 °C, however, major bands of reserve protein decreased in staining intensity and new bands with greater migration velocity appeared; banding still occurred at 100 °C. Distribution patterns of glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), nonspecific α-esterases (α-EST), and leucine aminopeptidase (LAP) reflected no change in banding or apparent enzyme activity at temperatures less than 45 °C. Complete inactivation was estimated for GDH at 80 to 85 °C, MDH at 65 °C, α-EST at 60 to 65 °C, and LAP at 60 to 65 °C. Isoenzymes of GDH, MDH, and LAP, and bands of α-EST exhibited differential thermal sensitivity. Peroxidase activity (using pyrogallol as the hydrogen donor) was not influenced through 65 °C; minimal reaction with benzidine occurred. No alkaline phosphatase activity was observed. Banding patterns of proteins or enzymes heated for 15 min were identical with those heated for 30 min. The results are compared with those of other studies regarding the influence of heat on proteins and enzymes in extracts of heated cotyledons from 5-day peanut seedlings and in extracts from wet- and dry-roasted seed.

Hymenolepis diminuta: an investigation of juvenile hormone titre, degradation and supplementation in the intermediate host, Tenebrio molitor

Parasitology ◽  
1990 ◽  
Vol 100 (3) ◽  
pp. 445-452 ◽  
Author(s):  
H. Hurd ◽  
C. Strambi ◽  
N. E. Beckage
Keyword(s):  
Juvenile Hormone ◽  
Intermediate Host ◽  
Topical Application ◽  
Post Infection ◽  
Reproductive Output ◽  
Endocrine System ◽  
Tenebrio Molitor ◽  
Hymenolepis Diminuta ◽  
Significant Difference ◽  
Female Control

SUMMARYMetacestodes of Hymenolepis diminuta cause a perturbance of vitellogenesis in the intermediate host Tenebrio molitor. The reduction in host reproductive output associated with infection may be due to this pathophysiology. Many of these events are regulated by host juvenile hormone (JH). A comparison of the titre of JH and its rate of degradation in female control and parasitized 15-day-old insects has been made. Haemolymph from female beetles contained 1·27 pMol JH equivalents/100 µl. No significant difference was associated with infection. However, topical application of a JH analogue, methoprene, at the time of infecion or 8 days post-infection reduced the significant accumulation of vitellogenin usually found in the haemolymph of females 12 days or more post-infection. These findings indicate that parasite-induced alteration of host vitellogenesis is not mediated via alteration in JH titres, although observations made after hormone supplementation suggest some form of interaction between the parasite and the host endocrine system.

EDEMA FACTOR AND PHOSPHOLIPASE RELEASE BY A STRAIN OF BACILLUS CEREUS

1964 ◽  
Vol 10 (5) ◽  
pp. 717-725 ◽  
Author(s):  
Robert A. Altenbern ◽  
Harold B. Stull
Keyword(s):  
Bacillus Cereus ◽  
Mitomycin C ◽  
Ultraviolet Light ◽  
Optical Density ◽  
Parent Strain ◽  
Actinomycin D ◽  
Spontaneous Release ◽  
Post Irradiation ◽  
Edema Factor ◽  
Ultraviolet Light Irradiation

After ultraviolet light irradiation, strain 6464 of Bacillus cereus lysed, resulting in the release of toxin, phospholipase, and mature phage particles. Small amounts of toxin and phospholipase produced by non-induced cultures were correlated with the infrequent spontaneous release of bacteriophage. Stationary incubation following ultraviolet induction results in a greater yield of toxin and phospholipase than post irradiation incubation on a shaker. Postirradiation incubation at temperatures below 37° either reduced (30°) or prevented (26°) toxin and phospholipase production. A clone was obtained which was sensitive to the phage from the parent strain and was presumably no longer lysogenic for it. This cured strain still exhibited ultraviolet-induced optical density decline accompanied by release of toxin and phospholipase. Mitomycin C would induce strain 6464 and the cured strain derived from it and both released toxin and phospholipase during mitomycin C induced lysis. The induced lysis of the cured strain could be prevented by postinduction treatment with inhibitors of synthesis of protein (chloramphenicol), RNA (actinomycin D), or DNA (5-fluorouracil deoxyriboside).

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