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Group Dr. Rübsam

Research Program

Overview

Our lab is interested in the early steps of gametogenesis in both male and female insects. Depending on the different life histories found among insects, both oogenesis and spermatogenesis is either completed at pre-adult stages or is a life-long process driven by the continuous mitotic activity of germ line stem cells. These germ line stem cells are in our spotlight. Using a combination of descriptive and functional approaches we are studying the regulation of germ line stem cells and the differentiation of their progeny.

Comparative Analysis of Early Oogenesis in Different Insect Groups

During the last two decades, Drosophila has become a paradigm for insect oogenesis. Against the background of the still growing set of new Drosophila data, we started (re-)examining early oogenesis in several insect orders with meroistic ovaries (Coleoptera, Megaloptera, Neuroptera, Hymenoptera, Diptera, Mecoptera, Heteroptera). These studies mainly aim at extracting the basic traits of insect oogenesis and should contribute to a deeper understanding of the evolution of insect oogenesis. The publication of our results is in progress.

Functional Analysis of Early Spermatogenesis in Triboliumcastaneum

Our interest in Tribolium spermatogenesis is to understand the molecular mechanisms underlying the formation, proliferation, maintenance, and differentiation of testicular stem cells and their progeny.The pioneering work on the gonadal stem cell niches of Drosophila demonstrated the suitability of insect gametogenesis as a stem cell model system, with a high impact on fundamental biological and medical research. However, only a small set of stem cell regulating genes could be identified in Drosophila so far. This is mainly due to technical limitations, since most mutations of relevant genes cause lethality at earlier stages. The generation and analysis of germ line and somatic clones in the gonad is time consuming and difficult to apply. These major constraints can be readily overcome by applying systemic RNAi in Tribolium. We performed dsRNA injections of Tc – orthologs of several Drosophila genes with a known function in germ line stem cell regulation (e.g. piwi, bgcn) and obtained highly specific and reproducible phenotypes. Future work aims at screening as many genes as possible for a potential function in germ line stem cell regulation. Thus, we hope to add some new genetic players to the regulatory scenery at the testis tip.

Lab alumni

Jutta Distler (Diploma Student)
Stephanie Hoffmann (Diploma Student)
Manfred Depner (Diploma Student)
Enrico Konrad (Master Student)

Honorary Lab Member

Jürgen Büning