|
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.
|
|
Hmyzí anti-stresové reakce vůči přírodním toxinům
FEDOR, Tereza
The aim of this bachelor thesis was to characterize the effect of Bt (Bacillus thuringiensis) toxin on adipokinetic hormone (AKH) levels in the brain, on the activity of digestive enzymes (lipases, proteases, glucosideases, amylases) in the midgut and on nutrient levels (lipids, proteins, glycides) in the haemolymph of the firebug (Pyrrhocoris apterus). Bt toxin was applied by injection to the adult males 24 hours before monitoring of the above mentioned physiological characteristics. The results showed that Bt toxin reduced AKH level in the brain, modulated level of nutrients in haemolymph, but did not change activity of digestive enzymes in the midgut.
|
|
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.
|
|
Hormonálně řízená obrana proti hmyzím patogenům
BODLÁKOVÁ, Karolina
The aim of this bachelor thesis was to characterize the effect of one insect pathogen (entomopathogenic nematode Steinernema carpocapsae) and one venom (from the honey bee Apis mellifera) on digestive enzymes (amylases, proteases, lipases), and on adipokinetic hormone production in the brain of the cockroach Periplaneta americana . The experiments were done with the adult male and female cockroaches from a colony kept in the Insectary in the Institute of Entomology BC CAS. The pathogen/venom were applied into the cockroach body by injection 24 hours before the processing. After that the activity of digestive enzymes in the midgut, and AKH level in the brain were monitored. The results showed that the nematode has no effect on enzymes, and on AKH level as well. On the other hand, the bee venom partially increased the activity of digestive enzymes, but the role of AKH in this process in not completely clear.
|
|
Dynamics of digestive enzymes in the gut of ticks \kur{Ixodes ricinus} during blood feeding on the host.
KONVIČKOVÁ, Jitka
Proteolysis of ingested blood proteins is a crucial physiological process in ticks. This thesis focuses on profiling of dynamics of digestive enzymes in the ticks Ixodes ricinus during the course of blood-feeding on the host and during digestive phase after detachment from the host. We have measured the activity of digestive peptidases (using specific fluorescent substrates and inhibitors). The enzyme activities were negligible at the early stage of bloodfeeding than increased dramatically towards the end of the feeding period and dropped down immediately after detachment from the host. The activity of most enzymes increased again during the digestive phase before oviposition of females or metamorphosis of nymphs. The protein level of each peptidase was confirmed by immunolocalization using Western blot analyses.
|