During the last funding period, we have made substantial progress on our goals to derive multiple human pluripotent stem cell lines, to characterize their ability to differentiate to diverse cell types and to bank lines for distribution to other researchers. We have found that human spermatogonial stem cell lines differentiate to different cell types in the dish (in vitro) but have limited differentiation abilities in vivo in transplantation to murine models. In contrast, both human embryonic stem cell lines and induced pluripotent stem cell lines show ability to differentiate to diverse somatic lineages and the germ line both in vitro and in vivo upon transplantation.
We have exceeded our goals for derivation of lines and characterization of their properties in vitro. In the next year, we will finalize characterization in order to deposit all lines, in a very-well characterized form into a central bank for distribution broadly in California and to other researchers, as well.