Dr. Steffen Lemke
Dr. Steffen Lemke
Im Neuenheimer Feld 230
Fon +49 6221 54-5553
ed.grebledieh-inu.soc TEA ekmel.neffets
Morphogenesis and the Evolution of Form
The morphology of an organism is shaped during its development, and ultimately its adult form rests on sequential changes in the shape of cells and tissues. Underlying these changes on the cellular level are changes in the actin cytoskeleton, which is modulated by the interplay of actin and non-muscle myosin II. These modulations on the cellular level are controlled by upstream patterning genes such as transcription factors or signaling pathways. As the link between patterning genes and cytoskeletal components that control cell shape is critical to understand the molecular basis of morphogenesis, evolutionary changes to this link will be critical to assess the molecular basis of morphological diversity.
To address these questions, research in our group focuses on understanding cell-mechanical and molecular principles that contribute to the evolution of gastrulation. As model system we have selected several different fly species from the insect order of Diptera (“true” flies), which during embryonic development differ in various aspects of gastrulation but are still closely enough related to be overall comparable.
Gastrulation is the first set of morphologically dynamic events during the embryonic development of multicellular animals, and often it is directly influenced by preceding genetic patterning. Gastrulation in the insect order Diptera is morphologically sufficiently complex to serve as a reasonable model for the generation and evolution of form. The insect order contains Drosophila as reference system, in which the genetic circuitries that pattern the embryo prior to gastrulation and that provide instructions for cell movement during gastrulation have been studied in detail. Drosophila gastrulation can be readily compared with gastrulation in related flies, because, on the one hand, gastrulation in all flies follows a similar set of morphogenetic transformations. On the other hand, gastrulation has diverged sufficiently between flies to be able to explore the evolution of morphogenetic differences. Research in our group focuses specifically on differences in gastrulation between Drosophila, the hover fly Episyrphus balteatus, and the midge Chironomus riparius.