Developmental Biology

Professor of Developmental Biology

- 1991 Diplom (Biology), Ludwig Maximilians University, Munich, Germany
- 1995 Dr. rer. nat., Max Planck Institute for Biophysical Chemistry, Göttingen (Germany) and Howard Hughes Medical Institute, Baylor College of Medicine, Houston (USA)
- 1995 – 1998 Postdoctoral Fellow and Associate, Howard Hughes Medical Institute, The Rockefeller University, New York (USA)
- 1998 – 2003 Assistant Professor and Robert Bosch Foundation "Junior Professor", Department of Genetics, University of Bayreuth, Bayreuth (Germany)
- since 2003 Professor of Developmental Biology at the Johann Friedrich Blumenbach Institute of Zoology and Anthropology, Georg August University, Göttingen (Germany)

Phylogenetic variance and plasticity
of developmental processes

A key question in developmental biology is how diverse animal body plans are specified. Early developmental decisions determine the coordinates of the embryo and activate the genetic circuitry that
sequentially subdivides and regionalizes the animal body. For insects, only in Drosophila melanogaster the early developmental events are known in molecular detail.

However, insects with varied life histories must compensate different reproductive strategies by adjusting the regulatory networks within the
developmental program. Therefore, phylogenetic differences between diverse species must be manifested in the genetic circuitries regulating embryogenesis.
To identify the plasticity in early developmental processes, we study their conservation and divergence in different arthropod species. Developmental regulatory genes code for signal transduction molecules and transcription factors. By insect transgenesis and functional genomics approaches, we analyze genetic interactions within the regulatory network of early embryogenesis in diverse arthropod species. This will help us to understand how animal evolution is based on changes in gene regulation governing early pattern formation.

Biology of Odoriferous Defensive (Stink) Glands

Beetles and ants are the most prolific producers of repellent and/or toxic compounds. Defensive substances are usually
multifunctional. As repellents, toxicants, insecticides, or antimicrobics, they
are directed against a large array of potential target organisms or may
function for boiling bombardment or as surfactants. Usually Coleoptera
biosynthesize and store their defensive compounds either in complex glands or
in the hemolymph and often release them by reflex bleeding. Tribolium castaneumuses prothoracic and abdominal odoriferous
glands to produce large amounts of specific quinone- and hydrocarbon-containing
defensive secretions to condition their microenvironment with toxic, repellent,
bacteriostatic and fungistatic oils. We are interested both in the development
of these glands as well as their biological function. We want to understand the
biosynthesis and controlled secretion of semiochemicals as well as the
mechanisms of self-protection against toxic substances at a molecular level. In
addition, the biological and ecological functions of many of these compounds
will only be revealed, when beetles devoid of specific compounds can be
employed in behavioural tests.

Biological function of odorant binding proteins.

The red flour beetle Tribolium castaneum with the possibility of transgenic approaches such as directed gene expression, powerful reverse genetics based on systemic RNA-interference, the recently published
full genome sequence, and its longevity offers a great system to address olfaction from the odour recognition and discrimination at the periphery to the analysis of the plasticity of the central olfactory pathway. In this project we combine transgenetic, reverse genetic, electrophysiological, chemical ecological, neurobiochemical and neuroanatomical approaches to study the correlation of odorants to odorant binding proteins (OBP) to odorant receptors (OR). The focus of the project will lay on the biological function of OBPs which is still largely unknown, despite their necessity for olfaction. Especially the interaction of OBPs with ORs will be of key interest. Moreover,
the established tools will also be applied to study postmetamorphic plasticity of the central olfactory pathway including the first central odour processing centers, the antennal lobes, and higher processing centers, the mushroom bodies.

Development of transgene-based ecological pest management programs.

We apply our knowledge about developmental processes to insect pest management. Current control efforts rely mostly on insecticides, but the costs for developing new chemical products to overcome the problem of insecticide resistance are escalating. Genetic control based on the sterile-insect technique (SIT) uses the release of sterile males to cause infertile matings which reduce pest population levels.

Due to the species specificity, SIT is considered an ecologically safe procedure. However, conventional sterilization by ionizing radiation also decreases the competitiveness of sterilized males. To overcome this problem, we design transgenic approaches to selectively produce vigorous and potent sterile males by generating conditional reproductive male sterility based on embryonic lethality. In addition we establish transgenic strategies to improve monitoring of SIT programs and develop methodologies to further improve the stability of
transposon-mediated transgene insertions by means of site specific integrations and molecular rearrangements using site specific recombination. Moreover, we further develop tools to use transgenic approaches in non-model organisms.