Functional in vivo Studies of Algal Sensory Photoreceptors


Channelrhodopsins, that we originally discovered in the green alga Chlamydomonas reinhardtii and described as a light-gated ion channels, revolutionized the field of neuroscience over the past decade by enabling neuroscientists to specifically activate selected neurons in large ensembles with short light flashes, a technology now known as "Optogenetics". The aim of this project is to go back to Chlamydomonas and to continue our early studies on the function of sensory photoreceptors in the alga. To accomplish such a goal we recently introduced several reliable methods for nuclear gene targeting (ZFN and Cas9). Within the first part of the proposal we will further optimize the gene targeting technology towards higher efficiency by testing new Cas-variants any by transient deletion of proteins that mediate non-homologous end-joining as ku70/80 or polymerase PolyQ. The second and third part of the proposal addresses Channelrhodopsin in vivo modifications (previously studied biophysically in vitro) in order to understand the function of the variants in their original cellular context and to understand ChR turn-over and processing during cell division and development. Within the fourth part of the project we will study the eight histidine kinase rhodopsins (HKRs), members of an only recently discovered family of enzyme rhodopsins, by gene disruption and modification, fluorescent labeling, super resolution microscopy in combination with Cryotomography. We will study the influence of HKRs on photosynthesis, stress responses, cell cycle regulation, gametogenesis, circadian rhythm, and zygote formation. The analysis will be supported by biophysical studies, super resolution microscopy, proteomic approaches and RNA-sequencing. This project will pave further grounds for specific algal-genome engineering and a new rational algal biotechnology, deepen our knowledge about algal sensory photoreceptors and provide new tools for Optogenetics in other research fields.


Principal Investigators
Hegemann, Peter Prof. Dr. (Details) (Experimental Biophysics)

Duration of Project
Start date: 06/2019
End date: 05/2021

Research Areas
Biophysics, Life Sciences, Natural Sciences, Plant Physiology

Last updated on 2021-15-09 at 12:05