Biochemistry, Department of


Date of this Version



PNAS, December 27, 2011, vol. 108, no. 52, 20859–20860; doi: 10.1073/pnas.1118670109


The availability of facile methods for targeted gene knockout and gene replacement based on homologous recombination in bacteria and yeast systems has driven rapid progress in understanding many of the complex metabolic and regulatory networks in prokaryotic and eukaryotic cells. The lack of such tools in other organisms is a major impediment to progress both in fundamental research and in research that is directed toward practical economic and societal outcomes. For example, the current goal to replace fossil fuels with renewable energy sources produced by plants and algae is hampered in both the short term and the long term by our limited knowledge of their metabolic systems and how they can be modified to create organisms that produce more and better energy-rich molecules. Thus, the report in PNAS by Kilian et al. (1) of efficient and reliable genetic transformation of the commercially important alga, Nannochloropsis, via homologous recombination is a significant step forward.