Most NBAC members seemed to lean toward approving stem cell research in the same two circumstances favored by the NIH: harvesting primordial germ cells
(the precursors of egg and sperm) from aborted children at about eight weeks' gestation, and killing "spare" embryos to obtain their stem cells.
Gearhart's group followed a different route, deriving their stem cells from the primordial germ cells
of fetuses aborted five to nine weeks after, fertilization.
Origen subsequently published research in June 2006 in Nature demonstrating its ability to make modifications to the chicken genome and create transgenic chickens by introducing the desired new genetic elements into primordial germ cells
, the precursor cells to sperm and eggs.
In humans, primordial germ cells
or oogonium are the first stage of development into ovums, or mature eggs.
Scientists identified developing stem cells containing the genetic signature of primordial germ cells
(PGCs), the ancestors of eggs and sperm Some cells also produced proteins only found in maturing sperm.
Derivation of Pluripotent Stem Cells from Cultured Human Primordial Germ Cells
," Proceedings of the National Academy of Sciences 95 : 13726-31).
Etches has made significant contributions over the past 10 years to Origen's success in developing a broadly applicable, robust technology for the production of transgenic chickens, using both embryonic stem cells and primordial germ cells
leading to numerous scientific publications and patent applications.
The team has coaxed mouse embryonic stem cells into sperm precursors, called primordial germ cells
(PGCs), and shown that these cells can give rise to healthy sperm.
Etches and van de Lavoir demonstrated that primordial germ cells
could be extracted from chicken embryos and grown in culture.
2006), PigVASA to identify proliferating primordial germ cells
(Luo et al.