The development of tools has always been a major

driving force for the advancement of science. Optical microscopes

were the first instruments that allowed discovery and

descriptive studies of the subcellular features of microorganisms.

Although optical and electron microscopes remained at

the forefront of microbiological research tools since their inventions,

the advent of molecular genetics brought about

questions which had to be addressed with new Bgenetic tools^.

The unicellular green microalgal genus Chlamydomonas, especially

the most prominent species C. reinhardtii, has become

a frequently used model organism for many diverse

fields of research and molecular genetic analyses of

C. reinhardtii, as well as the available genetic tools and techniques,

have become increasingly sophisticated throughout

the last decades. The aim of this review is to provide an overview

of the molecular key features of C. reinhardtii and summarize

the progress related to the development of tools and

techniques for genetic engineering of this organism, from

pioneering DNA transformation experiments to state-of-theart

techniques for targeted nuclear genome editing and highthroughput

screening approaches.