Our aims for RC1-00137 entitled “Human Oocyte Development for Genetic, Pharmacological and Reprogramming Applications” are as follows: Aim 1) Assess and compare the potential of multiple nonfederal hESC lines to contribute to the germ cell lineage. Aim 2) Differentiate hESCs to oocytes. Aim 3) Assay the ability of differentiated germ cells to reprogram a somatic nucleus. In the last funding cycle, we have succeeded in extending our analysis of human embryonic stem cell lines and differentiation of the germ cell lineage (that gives rise ultimately to oocytes or eggs) to 11 lines (initially, we proposed 12 lines in total). We have demonstrated that we can control or regulate germ cell differentiation in vitro to increase numbers of germ cells via external and internal induction, and we have succeeded in differentiating germ cells that enter and progress through meiosis, in multiple lines. We have developed the ability to use transplantation to promote mouse oocyte (egg) differentiation (in parallel studies); these studies form the foundation for applying our methods to human oocyte formation. Finally, we have published the results of our studies aimed at development of methods to mature human oocytes in vitro in a dish and derive hESC lines from single blastomeres. The later have also included analysis of epigenetic modifications during human embryo development to potentially enhance the ability to derive optimal lines from single cells via SCNT (somatic cell nuclear transfer).
As the field of human pluripotent stem cell research has advanced, it has become clear that there is a need to consider the potential importance of SCNT to complement other methods of derivation of isogenic stem cell lines, in addition to generation of induced pluripotent stem cell lines (iPSCs). In addition, we have the ability to learn much about basic and clinical properties of human germ cells through differentiation and maturation and we can apply methods to help men and women with reproductive health problems.
Our publications are: 1) McElroy SL, Byrne JA, Chavez SL, Behr B, Hsueh AJ, Westphal LM, Reijo Pera RA. (2010) Parthenogenic blastocysts derived from cumulus-free in vitro matured human oocytes. PLoS One 5: e10979. This publication reports the first blastocyst derived from parthenogenic activation of immature oocytes (from the GV stage) to reach maturity (McElroy, Byrne et al. 2010). 2) Kee K, Angeles VT, Flores M, Nguyen HN, Reijo Pera RA (2009) Human DAZL, DAZ and BOULE genes modulate primordial germ cell and haploid gamete formation. Nature 462, 222-5. Note that the research reported in this publication was supported in part by CIRM (development of methods for human germ cell differentiation)(Kee, Angeles et al. 2009). In addition, we reported this publication in the last report as in press. It has now been published.