Sponsored Projects for Undergraduate Research

Improving Transgene Expression in Microalgae Felix de Carpentier – Niyogi Lab – PMB Transgenic gene expression is very challenging in the model green microalgae Chlamydomonas reinhardtii. To date, research has focused on attenuating epigenetic silencing, optimizing regulatory sequences, and increasing mRNA stability 1. However, in Chlamydomonas, the transgenes are randomly inserted in the nuclear genome. This causes a very large variability in the level of expression of the resulting proteins. The transformed fragments contain a gene of interest but also an antibiotic resistance gene as selectable marker. It was hypothesized that better expression consistency could be achieved if this selectable marker is the limiting factor 1. In such a setup, only favorable insertion loci would lead to transformants. To do that, we propose to use antibiotic resistance proteins which level of resistance linearly increases with quantity. This project aims at developing this type of selectable markers, such as AAC6’29b 2. We have already cloned it and shown that it can induce kanamycin resistance in Chlamydomonas. The next step is to test its efficacy and characterize it in depth. Achieving of these goals could greatly improve transgene expression; a long-lasting problem is Chlamydomonas. References 1. Schroda, M. (2019). Good News for Nuclear Transgene Expression in Chlamydomonas. Cells 8, 1534. 10.3390/cells8121534. 2. Magnet, S., Smith, T.-A., Zheng, R., Nordmann, P., and Blanchard, J.S. (2003). Aminoglycoside Resistance Resulting from Tight Drug Binding to an Altered Aminoglycoside Acetyltransferase. Antimicrob. Agents Chemother. 47, 1577–1583. 10.1128/AAC.47.5.1577-1583.2003.