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05/17/2016 MOLIFE RESEARCH SEMINAR: Dr. Julia Oswald

Tuesday, May 17, 2016 - 13:00
Lecture Hall of Research II


Talk by:

Dr. Julia Oswald, Cambridge University (group of William Harris)

Title of the talk:

The Role of Notch Signalling in Retinal Cell Fate Specification in Zebrafish

The zebrafish retina is comprised of five neuronal cell types, including retinal ganglion cells, amacrine cells, horizontal cells, bipolar cells and photoreceptors, as well as a single type of glial cell, the Müller glia, which are born in a conserved histogenic order from equipotent, pluripotent retinal progenitor cells. Upon differentiation all retinal cell types are arranged in highly organized layers, constituting a complex neuronal network. In order to shape a complex tissue like the retina, several developmental processes including cell proliferation, differentiation and cell death need to be tightly regulated to ensure the generation of different neuronal cell types in correct amounts and at the right location. For those processes to be coordinated during development, various signalling pathways and fate determinants are required to interact. However, the nature of crosstalk between pathways such as Notch signalling and key regulators of lineage commitment and cellular differentiation is only starting to be understood.

During early zebrafish development, Notch signalling components are expressed in a gradient across the retinal epithelium, leading to the assumption that spatial localisation of interacting cells influences the direction of Notch signalling. However it is unknown whether Notch signalling works mainly between sister cells and it is debated whether, apart from determining glial fate and pushing progenitor cells to exit the cell cycle, it has any direct impact on the neuronal fate decisions in the retina.
In order to approach this question, Notch signalling was monitored in-vivo using fluorescence-based reporter constructs and transgenic zebrafish lines, employing confocal and lightsheet imaging techniques. Subsequently, using various loss and gain of function approaches, including morpholinos, pharmacological and genetic manipulation, I focused on elucidating the effects of Notch signalling on cell fate determination within defined developmental timeframes. In summary, the results of those experiments provide evidence for a direct involvement of Notch signalling in bipolar fate determination and highlight the presence of a previously unnoticed molecular switch mechanism by which amacrine/horizontal and bipolar/glial lineages are balanced during development.

Further info: Prof. Dr. Sebastian Springer, Professor of Biochemistry and Cell Biology, Focus Area: Health - Life Sciences & Chemistry, Email:  s.springer [at], Tel: +49 421 200-3243, Link to Homepage: