PARENT SESSION
MINISYMPOSIUM VIII. IN VITRO PRODUCTION OF MALE AND FEMALE GAMETES FROM STEM CELLS

Tuesday, August 3, 2004
9:00 AM–10:30 AM
Buchanan A100
Chair: Ryuzo Yanagimachi (University of Hawaii School of Medicine, Honolulu, HI)

(MS23) DIFFERENTIATION OF OOCYTES FROM EMBRYONIC STEM CELLS.

Hübner, Karin¹, Fuhrmann, Guy², Christenson, Lane³, Kehler, James¹, Reinbold, Rolland¹, De La Fuente, Rabindranath¹, Wood, Jennifer³, Strauss, III, Jerome³, Boiani, Michele¹, Schöler, Hans^{1, 4}, ¹ University of Pennsylvania, Kennett Square, PA² Centre de Neurochimie, Strasbourg Cedex, France³ University of Pennsylvania, Philadelphia, PA⁴ Max-Planck-Institute for Molecular Biomedicine, Münster, Germany

ABSTRACT- Continuation of the species requires the formation and development of sexually dimorphic germ cells. Cultured embryonic stem cells have long been considered pluripotent rather than totipotent due to the failure to detect germline cells under differentiating conditions. However, several laboratories have now demonstrated the generation of germ cells from cultured mouse and human embryonic stem cells. Our original studies demonstrated that mouse embryonic stem cells in culture could develop into primordial germ cells of all developmental stages. These cells express redundant (Oct4, c-Kit, Vasa) genes indicative of germ cells at early stages of development. These germ cells followed the oogenesis pathway as evidenced by expression of the meiotic markers Scp3 and Dmc1 and the development of a zona-pelucida structure. Moreover, these germ cells were able to recruit adjacent cells to form follicle-like structures capable of steroid biosynthesis. Lastly we observed blastocyst-like structures in these cultures that expressed the trophectodermal markers Hand1, Pl-1 and TpBp by RT-PCR. Furthermore, these structures share with blastocysts a similar expression pattern by IHC, with Troma-1 localized to the outer cells and Oct4 restricted to the inner cells. Oogenesis in culture should contribute to various areas including nuclear transfer, manipulation of the germline, and advance studies on fertility treatment and germ and somatic cell interaction and differentiation.

KEY WORDS: totipotency, blastocysts, embryonic stem cells, oocytes