15 documents found

Dissertation
CC BY 3.0
2019

Plant cell wall degradation in Coleoptera : investigation of three glycoside h ...

The first line of defense against biotic and abiotic stresses in plants consists of a diverse set of sugar-based compounds forming the plant cell wall. The major component of the plant cell wall is cellulose, a polysaccharide consisting of β-1,4-linked glucose moieties. Any organism being able to degrade...
Dissertation
All rights reserved
2016

Ecological immunology and host plant adaptation in lepidopteran herbivores

Herbivore Insekten leben in komplexen Habitaten in denen sie mit vielen verschiedenen Pathogenen interagieren müssen. Um dieser Herausforderung gerecht zu werden, benötigen sie entsprechende Abwehrmechanismen, welche gezielt und schnell Mikroorganismen erkennen und bekämpfen. Die Bedrohungen innerhalb...
Dissertation
All rights reserved
2016

ABC transporters in insect detoxification pathways : ABC transporters in insec ...

Almost half of all insects in the world feed on plants; however plants exploit defense mechanisms of both physical and chemical nature, such as secondary metabolites. Insects on the other hand have developed ways to circumvent these defense barriers, for example by detoxifying the secondary metabolites...
Dissertation
2014-06-03

Drosophila olfactory neuroecology : function and evolution

Olfaction is the single most studied means of insect chemoreception. Many insects are sensitive to olfactory signals that advertise relevant ecological information concerning nutrient resources, competitors, predators, potential mates, and host suitability (Price et al., 2011). The olfactory system of...
Dissertation
2014-04-29

Revealing manduca sextas nicotine metabolism and its ecological consequences...

Insects have developed a myriad of adaptations to live and evolve. Manduca sexta, a specialist lepidopteran herbivore of Nicotiana attenuata, has developed a remarkable adaptation to tolerate a toxic alkaloid ‘nicotine’ that it ingests from its host plant Nicotiana attenuata. The mechanism of nicotine...
Dissertation
2014-04-07

Odor guided behavior and its modulation in the fruit fly Drosophila melanogaster

Geosmin is produced by a group of microbes, is highly aversive to Drosophila. We furthermore showed that Drosophila has one type of sensory neurons expressing an odorant receptor (OR 56a) that is extremely sensitive and fully dedicated to detect this compound. The Geosmin detection System is conserved...
Dissertation
2014-02-12

Response dynamics in drosophila olfaction

Insects are ecologically and economically important organisms. They are pollinators, pests and vectors for many deadly human and animal diseases. Insects are highly dependent on olfaction to locate hosts, oviposition sites, and dangers. Olfactory organs are the main sensory channel through which insects...
Dissertation
2013-07-23

Odor Coding Strategies in the Drosophila Olfactory Circuit

This dissertation thesis unravels various strategies of the Drosophila melanogaster olfactory circuit to decode the olfactory world into an accurate perception of odors underlying innate odor-guided behavior. The olfactory system is an extremely flat but elegantly organized circuitry, which is optimized...
Dissertation
2013-06-17

The alpha-linolenic acid requirements of developing heliothines

Lepidoptera cannot synthesise α-18:3 and must therefore obtain it from dietary sources. An α-18:3 deficiency has little effect on larval growth, but leads to abnormalities in pupation and adult eclosion. In order to compare the α-18:3 requirements of Heliothis virescens (a generalist) and Heliothis subflexa...
Dissertation
2012-12-10

Genetic diversity of Lymantria spp. in relation to their host trees : a cDNA-A ...

Plant-insect interactions are a wide and diverse field of study. Abiotic and biotic factors influence the dynamic interaction between plants and their insect herbivores. Lymantria dispar (gypsy moth), Lymantria monacha (nun moth) and Tortrix viridana (green leaf oak roller) are important forest pest...
Dissertation
2012-01-03

Emerging model spedies driven by transciptomics

This work is focused on 'emerging model species', i.e. question-driven model species which have sufficient molecular resources to investigate a specific phenomenon in molecular biology, developmental biology, molecular ecology and evolution or related molecular fields. This thesis shows how transcriptomic...
Dissertation
2011-11-09

Characterization of caspases from Lepidoptera and their role in apoptosis

Multicellular organisms need a tightly controlled regulation of cell proliferation and of cell specialization together with a controlled cell death to maintain their integrity. A family of evolutionarily conserved proteases, called caspases, plays a central role in regulating apoptosis in animals. The...
Dissertation
2011-10-26

Identification and characterization of defense related enzymes in Chrysomelina...

Glandular chemical defense of Chrysomelina larvae is either, not (iridoids), in part, or completely dependent (salicylaldehyde) on host derived glucosides. After uptake of glucoside precursors into the glandular reservoir, deglucosylation and further modification to defensive compounds falls into line....
Dissertation
2009-07-27

Evolutionary Origins and Molecular Mechanisms of Hostplant Adaption in...

Although the defensive and counter-defensive molecules underlying many ecological interactions are known, the genetic mechanisms controlling these molecules are often unknown. Knowledge of these mechanisms, as well as the selective forces and adaptations that have shaped them, is necessary if we are...
Dissertation
2009-07-10

Immunity and physiology of Lepidoptera is influenced by midgut mediated...

Die meisten Organismen auf der Erde werden von Pathogenen bedroht. Um sich gegen Pathogene zu schützen, haben Organismen ein oftmals komplexes Immunsystem entwickelt. Das Immunsystem hat viele unterschiedene Zellulare und Humorale Komponenten. Verschiedene Komponenten des Immunrepertoires sind aktiv...