Kehkooi KEE (China)
Kehkooi Kee received his Bachelor and Master degrees in Biochemistry at Iowa State University in 1997. He studied meiotic recombination during his graduate school at Weill Cornell Medical School and Sloan Kettering Institute in Prof Scott Keeney laboratory. After his PhD study, he joined Prof Renee Reijo Pera lab as a postdoctoral fellow at UCSF followed by a research associate position at Stanford University. He started his own lab and became a principal investigator at School of Medicine, Tsinghua University since 2010. His research team is interested in understanding the molecular mechanisms underlying human germ cell development, initiation of meiosis, and impacts of human germ cells on early embryo development. Their current research projects include developing in vitro models of human germ cell development and studying mutations causing infertility manifested in clinical setting.
In Vitro Differentiation of Human Embryonic Stem Cells into Ovarian Follicle-Like Cells
Studies of human germ cell development had been hindered by sample procurement. Human embryonic stem cells provide them unprecedented opportunity to develop in vitro differentiation system to study these mechanisms. Developing an in vitro differentiation system of human stem cell into oocytes will greatly facilitate us to study the unique mechanisms of human oogenesis. Specialized cell types and organoids have been derived from human pluripotent stem cells in vitro, but generating the human ovarian follicle remains a challenge. We have developed a system in which human embryonic stem cells (hESCs) can be differentiated into ovarian follicle-like cells in vitro. First, we found that an RNA binding protein specifically expressed in germ cells, DAZL, regulates the exit from pluripotency and the entry into meiosis during hESC differentiation. By combining DAZL with the growth factors GDF9 and BMP15, these meiotic germ cells are further induced to form ovarian follicle-like cells (FLCs), including oocyte-like cells and granulosa-like cells. This in vitro differentiation system will allow us to study the unique molecular mechanisms involved in human pluripotent stem cell differentiation into late PGCs, meiotic germ cells, and the ovarian follicle.