RT Journal Article SR Electronic T1 Exploring the impact of terminators on transgene expression in Chlamydomonas reinhardtii with a synthetic biology approach JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.08.04.455025 DO 10.1101/2021.08.04.455025 A1 Katrin Geisler A1 Mark A. Scaife A1 Paweł M. Mordaka A1 Andre Holzer A1 Payam Mehrshahi A1 Gonzalo Mendoza Ochoa A1 Alison G. Smith YR 2021 UL http://biorxiv.org/content/early/2021/08/04/2021.08.04.455025.abstract AB Chlamydomonas reinhardtii has many attractive features for use as a model organism for both fundamental studies and as a biotechnological platform. Nonetheless, despite the many molecular tools and resources that have been developed, there are challenges for its successful engineering, in particular to obtain reproducible and high levels of transgene expression. Here we describe a synthetic biology approach to screen several hundred independent transformants using standardised parts to explore different parameters that might affect transgene expression. We focused on terminators and, using a standardised workflow and quantitative outputs, tested 9 different elements representing three different size classes of native terminators to determine their ability to support high level expression of a GFP reporter gene. We found that the optimal size reflected the median size of element found in the C. reinhardtii genome. The behaviour of the terminator parts was similar with different promoters, in different host strains and with different transgenes. This approach is applicable to the systematic testing of other genetic elements, facilitating comparison to determine optimal transgene design.Competing Interest StatementThe authors have declared no competing interest.