Research Summary:
Most of our research revolves around the chloroplast genome of plants and algae, which we view as a simpler model genome (compared to the nucleus) for understanding genome expression, regulation, and evolution. We have paid particular attention to the introns, since they have dynamic functions, such as self-splicing and the ability to spread to new alleles. Also, during evolution, they can move horizontally to new genes or even new organisms. We have also studied the circadian regulation of chloroplast transcription, and more recently the translational role of a novel rhodanese-domain protein. A few years ago we began to use a novel intron-encoded endonuclease, I-CreII, to study how chloroplasts repair a broken chromosome; surprisingly little is known about DNA repair in this constantly stressed organelle. This work is being performed with Chlamydomonas spp., Arabidopsis, and tobacco, as these organisms offer complementary advantages for the study of chloroplast genomics. Like many other researchers, we have become interested in biofuels, especially from algae. We initiated a project on anaerobic metabolism in Chlamydomonas, which produces ethanol, hydrogen, and organic acids from photosynthetically fixed starch, when oxygen is limiting. We are trying to increase the amount of ethanol that is produced by using metabolic engineering.