The original goal of this project was to generate oocytes (eggs) from human embryonic stem (hES) cells in cell culture dishes in the laboratory. Such oocytes could be of use as vehicles to reprogram the DNA from cells of patients with life-threatening or debilitating conditions, thereby allowing generation of new lines of hES cells that are immune matched to the patient. The paucity of donated human oocytes precludes research using such material, and production of human oocytes from hES cells in the laboratory would in theory provide a limitless source of material.
Since our last progress report another CIRM-funded group, Dr. Renee Reijo Pera’s lab at Stanford University, has published exciting results demonstrating successful production of primordial oocytes from mouse ES (mES) and human ES (hES) cells. Consequently, during the remaining period of the award we propose to use the Reijo Pera methods for production of female germ line cells in our lab using H9 and HUES-9 female hES cells. After accomplishing this, we will introduce human mtDNA containing mutations that cause either a severe or mild reduction in oxidative phosphorylation (energy) production into H9 and HUES-9 hES cells and investigate the impact of the different mtDNA mutations on the ability of hES cells to form cells with characteristics of PGCs, then primordial oocytes in vitro and in vivo. An important related goal of this research is to investigate whether development of oocytes from ES cells could be used as a method to remove deleterious mtDNA mutations from the hES cell population, thereby improving the utility and possibly safety of derived cell types for therapeutic purposes.