Ergosterol is the major sterol found in the membranes of Chlamydomonas reinhardtii. Ergosterol is an end-product sterol primarily found in fungal organisms like yeast. While past studies have identified some ergosterol mutants in C. reinhardtii, very little is known about the sterol biosynthesis pathway in this species. The model organism, C. reinhardtii, is very unique in the sense that it accumulates ergosterol in its membranes. With the elucidation of the Chlamydomonas genome, bioinformatics analysis has allowed the determination of potential genes involved in ergosterol biosynthesis. With this knowledge, a working model of the pathway has been designed. Ultimately, the goal of this project is to employ molecular biology techniques to complement sterol mutations in yeasts with ergosterol genes from Chlamydomonas reinhardtii. Complementation would allow us to amplify the sterol genes from Chlamydomonas reinhardtii, transfer those genes into the previously characterized sterol mutants of the yeast, Saccharomyces cerevisiae, and characterize their function in a heterologous species. Better understanding of this pathway and the genes involved will also provide new information about the evolution of this species and possibly other algal systems. In addition, it will advance the understanding of lipid biosynthesis in this model system. Broader Impacts
Broader Impacts: As the national leader in producing the largest number of STEM (Science, Technology, Engineering and Mathematics) students who go on to receive Ph.Ds, Xavier University has upheld a reputation for excellence in the sciences. Students will have an opportunity to participate in a project that incorporates lipid biochemistry, as well as molecular biology techniques that will train and prepare them for the rigors of graduate school at other institutions. This project will help to continue to support the infrastructure of students who are interested in pursuing successful careers in the sciences.
Ergosterol is the major sterol found in the membranes of Chlamydomonas reinhardtii, a unicellular algal model system. This project was designed to continue the elucidation of potential genes involved in the ergosterol biosynthetic pathway. The goal of this project was to employ molecular biology techniques to complement sterol mutations in eukaryotic yeasts with ergosterol genes from Chlamydomonas reinhardtii. Complementation allowed us to amplify the sterol genes from Chlamydomonas reinhardtii and transfer those genes to previously characterized sterol mutants in Saccharomyces cerevisiae and characterize their function in a heterologous species. Our lab utilized readily available bioinformatics tools to characterize the genetic function and also look specifically at the similarities and differences between the actual sequences in the proteins of both species. The intellectual merit of this project focused on better understanding of the field of lipid biosynthesis in Chlamydomonas. In past and present research, scientists have believed that Chlamydomonas synthesizes its lipids by way of a cycloartenol bifurcation pathway. The experiments performed in this project seek to support these findings. Enhancing the knowledge in this field may lead to future innovations in biofuel production and technology innovation. The broader impact of this project was to provide support for the infrastructure of students who are interested in pursuing successful careers in the sciences. Creating an atmosphere of diversity in the sciences is key in promoting successful undergraduate researchers.