Plants perceive UV-B radiation and adapt to it. Arabidopsis thaliana senses UV-B through its photoreceptor AtUVR8. Studying UV-B signalling and response in other organisms of the green lineage may provide information on its evolutionary conservation. The green alga Chlamydomonas reinhardtii acclimates to UV-B and was shown to possess a functional ortholog of AtUVR8 that is likely the UV-B photoreceptor critical for UV-B acclimation. In the course of this project, a new assay to determine Chlamydomonas UV-B acclimation based on colony survival was established. In addition, Gateway compatible vectors for expression of epitope-tagged protein in Chlamydomonas were generated. A CrUVR8W281A variant was analysed to characterized CrUVR8 function. Moreover, a TALEN-based approach was used in an attempt to generate a cruvr8 mutant essential to study CrUVR8 involvement in UV-B signalling. However, despite codon-optimization, no TALEN protein expression could be detected and no mutant could be generated.