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Biosynthesis of terpenoid secondary metabolites in termites
Jungwirth, Daniel ; Heidingsfeld, Olga (advisor) ; Buček, Aleš (referee)
Terpenoids are natural compounds, which can be found in the form of tens of thousands diverse molecules in all forms of life. Terpenoids are mostly represented in plants, microorganisms,and animals. It should not be a surprise that terpenoids are often found in insects, the most species-rich class of Metazoa. In insects terpenoids are mostly used for communication as pheromones and for chemical defence. In comparison to widespread knowledge of terpene (and terpenoid) biosynthesis in plants we lack thorough knowledge in insects. Studies conducted in past few years showedthat the ability to synthesize terpenoids has occurred independently and repeatedly in various lineages of insects. It was also found that terpene synthase genes evolved via duplication and neofunctionalization of specific genes, which were responsible for isoprenyldiphospate synthesis. Despite these discoveries the terpenoid synthesis in insects is mostly unknown and remains to be elucidated. This thesis aims to functionally characterize three candidate terpene synthases from the termite Nasutitermes takasagoensis. Expression of selected proteins was done in two bacterial systems. For the purification of recombinant proteins immobilized metal ion affinity chromatography was used. Detection of products from assays with purified...
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Study of evolution of insect pheromone biosynthetic fatty acyl desaturases
Buček, Aleš
Insects account for more than one million of described species with an ecological and economic impact disproportional to their minute body size. Among the factors which have contributed to their evolutionary success, insect secondary metabolites such as defensive compounds and chemical signals are regarded to play a major role. This thesis aims at uncovering the molecular mechanisms underlying evolution of ubiquitous insect secondary metabolites - sex pheromones (SPs), i.e. chemical signals mediating mate finding and mating between individuals of the same species. The thesis focuses on a class of oxidoreductase enzymes, membrane fatty acid desaturases (mFADs), which introduce double bonds into hydrocarbon chains of fatty acyls and thus produce precursors of unsaturated fatty acid- derived SPs. mFADs are involved in SP biosynthesis in e.g. moths (Lepidoptera), flies (Diptera), cockroaches and termites (Blattodea), wasps and bees (Hymenoptera) - some of the most species-rich insect orders. Since SPs are principal to species reproductive isolation, uncovering the molecular basis of insect SP biosynthesis holds promises to contribute to answering fundamental questions concerning the insect ecology and evolution. The insect mFADs with diverse enzymatic specificities also represent a naturally available...
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Study of evolution of insect pheromone biosynthetic fatty acyl desaturases
Buček, Aleš ; Pichová, Iva (advisor) ; Žďárek, Jan (referee) ; Doležel, David (referee)
Insects account for more than one million of described species with an ecological and economic impact disproportional to their minute body size. Among the factors which have contributed to their evolutionary success, insect secondary metabolites such as defensive compounds and chemical signals are regarded to play a major role. This thesis aims at uncovering the molecular mechanisms underlying evolution of ubiquitous insect secondary metabolites - sex pheromones (SPs), i.e. chemical signals mediating mate finding and mating between individuals of the same species. The thesis focuses on a class of oxidoreductase enzymes, membrane fatty acid desaturases (mFADs), which introduce double bonds into hydrocarbon chains of fatty acyls and thus produce precursors of unsaturated fatty acid- derived SPs. mFADs are involved in SP biosynthesis in e.g. moths (Lepidoptera), flies (Diptera), cockroaches and termites (Blattodea), wasps and bees (Hymenoptera) - some of the most species-rich insect orders. Since SPs are principal to species reproductive isolation, uncovering the molecular basis of insect SP biosynthesis holds promises to contribute to answering fundamental questions concerning the insect ecology and evolution. The insect mFADs with diverse enzymatic specificities also represent a naturally available...
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Study of evolution of insect pheromone biosynthetic fatty acyl desaturases
Buček, Aleš
Insects account for more than one million of described species with an ecological and economic impact disproportional to their minute body size. Among the factors which have contributed to their evolutionary success, insect secondary metabolites such as defensive compounds and chemical signals are regarded to play a major role. This thesis aims at uncovering the molecular mechanisms underlying evolution of ubiquitous insect secondary metabolites - sex pheromones (SPs), i.e. chemical signals mediating mate finding and mating between individuals of the same species. The thesis focuses on a class of oxidoreductase enzymes, membrane fatty acid desaturases (mFADs), which introduce double bonds into hydrocarbon chains of fatty acyls and thus produce precursors of unsaturated fatty acid- derived SPs. mFADs are involved in SP biosynthesis in e.g. moths (Lepidoptera), flies (Diptera), cockroaches and termites (Blattodea), wasps and bees (Hymenoptera) - some of the most species-rich insect orders. Since SPs are principal to species reproductive isolation, uncovering the molecular basis of insect SP biosynthesis holds promises to contribute to answering fundamental questions concerning the insect ecology and evolution. The insect mFADs with diverse enzymatic specificities also represent a naturally available...
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