About the Course

The aim of this practical course is to train young investigators who wish to use Chlamydomonas as a new experimental system in their research. The major objective of the course is to present the basic genetic and molecular tools available and to illustrate with concrete examples how to use them for solving problems related particularly to organellar biogenesis, photosynthesis and flagellar function.

In recent years Chlamydomonas has emerged as a powerful model system for studying several important biological problems such as chloroplast and mitochondrial biogenesis and function, photosynthesis, assembly of flagella, phototaxis, cell wall synthesis, mating reactions and gametogenesis, and carbon, nitrogen and sulfur metabolism. This unicellular green alga undergoes a well defined sexual cycle and current research benefits from nearly half a century of genetic analysis. Because photosynthetic function is dispensable provided a reduced carbon source such as acetate is added to the growth medium, this organism has been particularly important for a genetic dissection of photosynthetic processes. Moreover, this organism has also been used very successfully for the analysis of flagellar assembly and function because Chlamydomonas cells lacking flagella are viable.

The technology for manipulating Chlamydomonas has advanced considerably. Efficient transformation methods have been developed for the nuclear and chloroplast genetic systems. Because of the high nuclear transformation yield, mutant genes can be isolated by genomic complementation with cosmid libraries. Chloroplast transformation occurs through homologous recombination and allows one to perform specific gene disruptions or site directed mutagenesis on plastid genes. Recently the chloroplast genome of Chlamydomonas has been sequenced. A draft of the nuclear genome of this alga is also available and over 280’000 ESTs have been sequenced. Moreover, publicly available microarrays exist. Nuclear reverse genetics has become feasible through newly developed methods for RNA interference in this alga. Thanks to these technological advances, Chlamydomonas is becoming a very useful model system and is attracting more and more researchers not only in the field of organellar biogenesis and photosynthesis but also in the field of flagella and cilia. Recent results have revealed that Chlamydomonas flagellar and basal body proteins display high sequence identity to human orthologs. Thus, results obtained with Chlamydomonas are relevant for understanding human diseases such as primary ciliary dyskinesis, polycystic kidney disease and retinitis pigmentosa.