Accèder directement au contenu

Associated laboratories : University of Heidelberg (Germany)

Center for Organismal Studies : COS

• Developmental Biology and Physiology
The lab is studying neuronal cell proliferation and differentiation in the developing, growing and regenerating eye and brain of fish (zebrafish, medaka) as model system. We are combining genetic, molecular and cell biological approaches with advanced imaging approaches to decipher the basic mechanisms that govern the balance of cell proliferation and differentiation in vivo. Special emphasis is given to follow the fate of proliferating and differentiating cells in the context of the fish retina and brain and to establish tools that allow visualizing the those processes in vivo. We take advantage of the life-long proliferation of retinal stem cells from the ciliary marginal zone (CMZ) that facilitates the continuous study of cells exiting the stem cell niche at the CMZ and their subsequent stereotypic differentiation. These processes can be functionally addressed by mutants established in a collaborative mutagenesis screen or available in the community. Novel tools developed in the lab allow to perform clonal analysis in 4D by the induction of the expression of genes of interest at physiological levels in individual retinal cells of any cell type.
Contact : Prof. Dr. Jochen Wittbrodt

• Developmental plasticity in plants
Developmental plasticity is a key adaptive process allowing organisms to cope with changes in their environment by modulating the phenotypes produced by a given genotype. This is particularly obvious in plants that constantly adapt their form. In parallel to this plasticity, there is a great regularity in the shape of the organs that plants continuously produce. How is the plant coping with both plasticity and robustness ? Our lab is interested in understanding the molecular and cellular basis of developmental plasticity/robustness. For this we use the model plant Arabidopsis thaliana and study the development of its root system, in particular the formation of the lateral roots. Specifically, we pursue two main lines of research :
 The role played by small RNAs molecules in this process.
 To understand the morphodynamics of lateral root formation.
Our research will lead to a better understanding of how organisms balance controlled stimulation and suppression of developmental programs. It will also shed lights on the cellular basis underlying plant organ morphogenesis.
Contact : Prof. Dr. Alexis Maizel

• Developmental Biology
Transcriptional Control of Development by Hox Proteins. Work in my group takes two major directions.
We have begun to systematically identify Hox downstream genes on the whole-genome level with the idea to identify and study all aspects of Hox dependent regulatory networks. To this end we have performed a comparative microarray screen probing six of the eight Drosophila Hox genes, which resulted in the first comprehensive atlas of Hox downstream genes containing many hundreds of transcripts. The second major goal of my lab is to understand how Hox proteins acquire spatio-temporal precision and cell-type specificity in regulating their target genes despite their broad expression.
Contact : Prof. Dr. Ingrid Lohmann

• Growth and Cell Fate Regulation
Multi-cellularity is a fundamental concept of life on our planet. This concept of single cells taking over special functions in interaction with other cells in a multicellular body is striking and requires a very complex system of cell-to-cell communication during growth and activity of organisms. Elucidating comprehensive concepts of the development and function of multicellular systems is therefore challenging, but also essential to understand their functionality. Lateral growth of plant shoots and roots is based on the tissue-forming properties of a group of stem cells called the cambium, the activity of which leads to the production of secondary vascular tissue. Considering its function as a stem cell niche that is essential for the constant production of new tissues, as well as its dependence on environmental cues, the cambium represents an ideal model for addressing questions concerning the regulation of cell identity and how growth processes are aligned with endogenous and exogenous requirements. Our laboratory investigates lateral plant growth in order to reveal general concepts of growth and development of multicellular organisms.
Contact : Dr. Thomas Greb