215 COMPARATIVE ANALYSIS OF PORCINE PLURIPOTENT CELL LINES DERIVED FROM SOMATIC CELLS AND VARIOUS EMBRYONIC ORIGINS

Abstract

Since pluripotent cells were first derived from the inner cell mass (ICM) of mouse blastocysts, tremendous efforts have been made to establish embryonic stem cell (ESC) lines in several domestic species including the pig; however, authentic porcine ESCs have not yet been established. It has proven difficult to derive pluripotent cells of naïve state that represents full pluripotency, due to the frequent occurrence of spontaneous differentiation into an EpiSC-like state during culture in pigs. We have been able to derive EpiSC-like porcine embryonic stem cell (pESC) lines of a differentiated non-ES cell state from blastocyst stage porcine embryos of various origins, including in vitro fertilized (IVF), in vivo derived, IVF aggregated and parthenogenetic embryos. In addition, we have generated induced pluripotent stem cells (piPSCs) via plasmid transfection of reprogramming factors (Oct4, Sox2, Klf4 and c-Myc) into porcine fibroblast cells. In this study, we analysed characteristics such as marker expression, pluripotency and the X chromosome inactivation (XCI) status of our EpiSC-like pESC lines along with our piPSC line. Our results show that these cell lines demonstrate the expression of genes associated with the Activin/Nodal and FGF2 pathways along with the expression of pluripotent markers Oct4, Sox2, Nanog, SSEA4, TRA 1-60 and TRA 1-81. Furthermore all of these cell lines showed in vitro differentiation potential; female XCI activity and a normal karyotype. Here we provide preliminary results that suggest that, as a nonpermissive species, the porcine species undergoes reprogramming into a primed state during the establishment of pluripotent stem cell lines.

This work was supported by the BioGreen 21 Program (#20070401034031, PJ0081382011), Rural Development Administration, Republic of Korea.