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Obranné reakce včel vůči přírodním toxinům
KAINZOVÁ, Klára
The aim of this master thesis was to describe the effect of honeybee venom on several physiological characteristics in the honeybees Apis mellifera themselves. They included the expression and level of vitellogenin in selected organs, AKHs production in CNS, level of dopamine in brain, fat body and Malpighian tubules, oxidative stress (the activity of catalase) and the structure of thoracic muscles in workers and drones. Results showed that the bee venom did not change the AKH level in CNS. However, the envenomation decreased the expression of vitellogenin in fat body, as well as the level of vitellogenin proteins both in fat body and haemolymph. Catalase activity was increased in the gut of workers but decreased in the gut of drones. The venoms application slightly increased dopamine levels in the fat body, brain and Malpighian tubules, but only in the fat body the rise was significant. Honeybee venom damaged the structures of myofibrils and mitochondria in the thoracic muscles of workers, however, co-application of the venom with AKH generally abolished this effect; situation in drones remains unknown.
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Obranné reakce hmyzu vůči intoxikaci: modelový druh včela medonosná
PROKŮPKOVÁ, Nela
This bachelor thesis aimed to characterize the effect of imidacloprid (neonicotinoid insecticide) on nutrient levels (carbohydrates, proteins, lipids) in haemolymph, on the activity of digestive enzymes (amylases, proteases, lipases) in the gut, and on adipokinetic hormone and biogenic amine levels in the central nervous system of the worker honeybees Apis mellifera. The insecticide was applied topically to the bee body at a dose of 0,04 micrograms per bee. The above-mentioned characteristics were measured 24 hours after insecticide application. The results showed that the effect of imidacloprid on the nutrient level in haemolymph was variable - the level of carbohydrates and proteins decreased, while the level of lipids increased. The activity of digestive enzymes in the gut increased (proteases, lipases) after the application of imidacloprid. On the other hand, the levels of adipokinetic hormone and biogenic amines in the central nervous system were reduced.
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Vliv přírodních toxinů na včelu medonosnou
KAINZOVÁ, Klára
The aim of this bachelor thesis was to describe the effect of honeybee venom on the activity of digestive enzymes (amylases, proteases, lipases), AKHs production in CNS, and level of nutrients (lipids, proteins, glycides) and vitellogenin in haemolymph of the honeybee Apis mellifera workers. Crude venom was applied into the honeybee body 24 hours before determination of the above mentioned characteristics. Results showed that the bee venom reduced the AKH level in CNS, increased activity of digestive enzymes in gut, and increased level of vitellogenin in haemolymph. Effect of the venom on nutrient level in haemolymph was variable - level of lipids and carbohydrates was enhanced, while level of proteins reduced.
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Úloha adipokinetického hormonu v metabolismu základních živin u octomilky obecné \kur{Drosophila melanogaster}
KUTHANOVÁ, Michaela
The aim of the thesis was evaluation of various metabolic characteristics in the fruit flies Drosophila melanogaster with deficiency of adipokinetic hormone (AKH) production, and with adenosine receptor dysfunction. The experiments were done with a goal to evaluate involment of AKH and adenosine into control of the metabolic pathways. For that measuring of basic nutrients, level of Drome-AKH, mortality and some others characteristics in the fruit flies during starvation were performed. Results revealed the effect of AKH on metabolism of storage nutrients, however, the role of adenosine was unclear.
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The anti-oxidative stress response in Drosophila malanogaster involvement of adipokinetic hormone and adenosine
Zemanová, Milada ; Kodrík, Dalibor
The anti-oxidative stress response was studied in Drosophila melanogaster larvae and adults with mutation in genes of adipokinetic hormone (Akh), and adenosine receptor (AdoR(1)), and both these genes together (Akh(1) AdoR1 double mutant). To elicit the oxidative stress we administered paraquat (PQ) in food. Mortality tests revealed the double mutant Akh(1) AdoR(1) was more sensitive to PQ toxicity than either of the single mutants. The PQ administration significantly increased the Drome-AKH hormone level in control w(1118) and AdoR(1) larvae. On the contrary, PQ significantly increased expression of glutathione S-transferase D1 (GstD1) gene. It seems that both functional adenosine receptor and AKH itself are important for the proper control of the GstD1 gene expression under oxidative stress. On the other hand, differences in glutathione S-transferase (GST) activity among the strains, and between untreated and PQ treated groups were minimal. Next, the glutathione (GSH) level was significantly lower in all untreated mutant groups as compared with untreated control w1118 flies and declined further when the flies were treated with PQ. Thus, we demonstrated the important role of AKH and adenosine in control of anti-stress response elicited by PQ in D. melanogaster model.
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A role of adipokinetic hormones in insect lipid metabolism
BÁRTŮ, Iva
This PhD. thesis summarizes the effect of adipokinetic hormones (AKHs) on a spectrum of mobilized lipids in model insect species the locust Locusta migratoria and the firebug Pyrrhocoris apterus. The results revealed that mobilization of diacylglycerols and fatty acids from the fat body into the haemolymph is not uniform and suggested there is partial specificity of individual AKHs. This could contribute to the answer of the question why some insect species have more than one AKH. The results of the thesis are supplemented by studies of AKH effect on lipid metabolism in stress conditions elicited by insecticide treatments. Co-application of AKH and insecticide enhanced the effect of insecticide
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Analysis of lipids mobilized by adipokinetic hormones in the firebug Pyrrhocoris apterur (Heteroptera: Pyrrhocoridae)
BÁRTŮ, Iva
An effect of two adipokinetic hormones (Pyrap-AKH and Peram-CAH-II) on distribution of diacylglycerol (DG) molecular species and their fatty acid (FA) constituents were investigated by liquid chromatography (HPLC) - electrospray ionization mass spectrometry (ESI-MS) in haemolymph of the firebug Pyrrhocoris apterus. The results show that DGs with characteristic FAs are preferentially mobilized from fat body (FB) by the action of both AKHs produced by P. apterus. Both the macropterous and brachypterous morphs show very close DG and FA profiles. A separate action of the Pyrap-AKH and the Peram-CAH-II, however, exerts distinct differences in FA distribution at the macropterous morph. It seems that partially C16 and mainly unsaturated C18 FAs play a dominant role in the AKH action with an exclusive position of linoleic acid (18:2) which represents 50 - 60% of the total DG mobilization. The metabolically active C16 and C18 FAs are preferentially absorbed from the linden seeds and accumulated in the FB.
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