PVi lines are pluripotent in tissue culture.

<p>PVi lines generate embryoid bodies (EBs) that contain cell types representing all 3 somatic germ layers as revealed by RT-PCR for molecular markers of ectoderm, endoderm, and mesoderm. This analysis also shows that embryoid bodies from many PVi lines contain <i>Vasa</i>-expressing cells, thereby suggesting the presence of germ cells.</p

PVi lines are pluripotent in vitro and in vivo.

<p>(<i>A–B</i>) Differentiation of PVi lines in tissue culture yields embryoid bodies. (<i>C</i>) Teratoma obtained following subcutaneous implantation of PVi cells (PVi3) into a NOD/SCID mouse. (<i>D–I</i>) Hematoxylin and eosin stained tissue from teratomas obtained from PVi3 (D, F, H) and PVi6 (E, G, I) shows cellular differentiation into mesodermal, endodermal, and ectodermal lineages. Scale bars equal 100 µm (A, B, D–I).</p

Induction and characterization of PVi lines.

<p>(<i>A</i>) Protocol for reprogramming PVEFs. All brightfield and immunolabeling images (B, C, E–J) depict colonies of a single representative PVi line (line 6). (<i>B–C</i>) Colony morphology of a PVi line. Colonies display morphology similar to that of mouse ES cells, including distinct raised colonies (B), with tightly-packed cells and well-defined, phase-bright margins (C). (<i>D</i>) RT-PCR for endogenous reprogramming factors in PVi lines. RT-PCR for pv-<i>Nat1</i> was performed as a positive control for an endogenous, ubiquitously expressed gene that should be expressed in all cells irrespective of their reprogramming state. Lanes 1–11 show PCR products from PVi lines 1–11, respectively. Lane 12 (“F”) shows PCR products from PVEFs. (<i>E</i>) PVi colony exhibiting alkaline phosphatase (Alk. phosphatase) activity. (<i>F</i>) Live immunofluorescent labeling of a PVi colony for SSEA-1. (<i>G–J</i>) Immunofluorescent labeling of PVi colonies for Nanog, Oct3/4, Klf4, and Sox2. Scale bars equal 500 µm (<i>B</i>), 100 µm (<i>C, E</i>), and 50 µm (<i>F–J</i>).</p