摘要:

AbstractChanges in protein and mRNA synthesis during embryonic morphogenesis of the polyembryonic parasitoidCopidosoma floridanumwere characterized by 1‐ and 2‐dimensional gel electrophoresis and quantified by scanning densitometry. Analysis of protein synthesis at different developmental stages indicated that embryonic molecular changes occurred at 36 h of the host's fourth stadium. These changes included decreased expression of 51 and 104 kD (D) proteins and increased expression of 22, 22.5, and 24 kD (D) proteins. Similarly, analysis of in vitro translation products indicated increased transcription of mRNA encoding 16 and 49 kD proteins in embryos dissected at 36 h of the host's fourth stadium. The stage‐specific changes in transcription and translation corresponded to the blastula stage of embryonic development and arose several hours before the initiation of embryonic morphogenic events associated with larval pattern formation. Application of the JH analogue methoprene at times that block morphogenesis but not blastula formation did not block the stage‐specific synthesis of any proteins. In contrast, neck ligation of hosts at times that block blastula formation and morphogenesis inhibited the synthesis of the 24 kD protein that was normally expressed at the blastul

ISSN:0739-4462    

DOI:10.1002/arch.940190202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractHeat shock proteins (hsps) were identified in a cell line from the Mediterranean fruit fly,Certatitis capitataWiedemann (Diptera: Tephritidae) exposed to elevated temperatures. Cells produced three hsps (Mr87,000, 69,000, and 34,000) in response to a temperature shift from 26°C to 37°C (30–60 min) with a concomitant decrease in synthesis of most other cellular proteins. Synthesis of low Mrhsps was not evident. The heat shock response is triggered within 30 min at temperatures from 33°C to 41°C. At temperatures>41°C protein synthesis was shut down. Within 2–3 h after return to 26°C, synthesis of proteins repressed at the higher temperatures resumed production while the major hsps disappear. Heat shock proteins were not produced in the presence of actinomycin D. Evaluations on the role of hsps in conferring thermotolerance to the cells showed an increase in cell viability in heat‐shocked cells over nonheat‐shocked cells (after 3 and 10 days) when subsequently placed at 45°C for 1 h, a normally lethal temperature. Heat shock alone had little effect on subsequent cell viability or growth at 26°C. These results suggest that hsps produced by these cells may aid in the maintenance of cell integrity and thus play a transitory role in

ISSN:0739-4462    

DOI:10.1002/arch.940190203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractInsecticides can affect the complex coordination of activities associated with reproduction through their sublethal impact on the nervous system. Our objective was to document the effects of a sublethal dose (1% mortality) of chlordimeform on reproductive events in the female cabbage looper moth,Trichoplusia ni. A significantly higher percentage of females treated with chlordimeform initiated calling at some time during the scotophase. Chlordimeform stimulated pheromone emission early in the scotophase. However, late in the scotophase pheromone emission was significantly lower in chlordimeform‐treated females when compared with control females. Overall, a lower amount of pheromone was detected in glands of chlordimeform‐treated females. This effect was significant only during the second half of the scotophase. We suggest that chlordimeform stimulates pheromone transport to the gland surface and calling behavior resulting in depletion of pheromone reserves over the course of the scotophase. Chlordimeform also decreased the mating success of males. Oviposition and egg hatch were also affected by chlordimeform. Mated females treated with chlordimeform laid significantly fewer eggs than acetone‐treated females. In addition, hatchability of eggs laid by mated femaleT. nitreated with chlordimeform was significantly lower than for eggs laid by control fe

ISSN:0739-4462    

DOI:10.1002/arch.940190204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe muscles of the stable fly oviduct were striated and in the common oviduct both circular and longitudinal fiber layers were present. Although two muscle layers were evident in the lateral oviducts, both consisted of an irregular lattice of longitudinal fibers with extensive branching. This branching between fibers seemed to provide a pathway for the spread of excitation because semi‐isolated preparations of the oviduct severed from their connections to the central nervous system continued to contract in a spontaneous and rhythmic manner. Compression or shortening of the longitudinal muscles of the oviduct was the predominant mode of activity. Both phasic contractions (1–2 s in duration) and tonic events (15–30 s in duration) were observed. Innervation of the oviduct arises from the four major branches of the median abdominal nerve trunk that enter the ovipositor. Five to seven peripheral nerve cells were found along these four branches. Electrical stimulation of the severed median abdominal nerve trunk caused the oviduct to respond to a single pulse. However, these individual responses approached a fusion at 6 pulses per second (pps). Two of five preparations showed an inhibition of spontaneous phasic concentrations and a noticeable drop in baseline tonus during and after a 10–20 s interval of stimulation at a frequency of 0.5–2 pps. Endogeneous electrical activity was recorded from branch nerves in the ovipositor after connections to the central nervous system were cut. Potentials of two distinct durations were evident in this recorded activity. The significance of this and other findings are

ISSN:0739-4462    

DOI:10.1002/arch.940190205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

Abstract32P‐Labeled fat bodies (32P‐fat bodies) ofRhodnius prolixusfemales were incubated in the presence of nonradioactive purified lipophorin and the release of radioactivity to the medium was analysed to answer the question of whether lipophorin is a reusable shuttle for phospholipids. The radioactivity found in the medium was associated with lipophorin phospholipids. When the32P‐fat bodies were incubated in the absence of lipophorin, only a small amount of radioactivity was released and it was not associated with lipophorin, indicating that there was no release of pre‐labeled32P‐lipophorin by the tissue. Analysis of the32P‐phospholipids transferred from fat bodies to the lipophorin particles by thin‐layer chromatography revealed a predominance of phosphatidylethanolamine and phosphatidylcholine, with minor amounts of phosphatidylserine, phosphatidylinositol, and sphingomyelin. The transfer of phospholipids to lipophorin was linear with time up to 45 min and the process was inhibited at low temperature and by the metabolic inhibitors azide and fluoride. The transfer of phospholipids from the fat bodies to lipophorin was saturable with respect to the concentration of lipophorin, which was half‐maximal at about 8 mg/ml. A directional movement of phospholipids from the fat body to lipophorin was observed. The net gain of phospholipids in 2 h of incubation with fat body was 8.54 nmol per insect, which corresponds to 6.69% of increase in the lipophorin phospholipid content. The rate of32P‐phospholipid transfer from fat body to lipophorin particles varied during the days after a blood meal increasing up to day 10 and then decreasing in parallel with the pro

ISSN:0739-4462    

DOI:10.1002/arch.940190206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940190207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940190201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY