Prep1 reconstitution rescues growth and differentiation of <i>Prep1</i>^-/- Embryoid bodies (EBs).

<p>(A) Prep1 KO1 ES cells where infected either with an empty vector (EV) or with a vector containing Prep1 cDNA. Their ability to form EBs was assessed along with WT ES cells infected with an empty vector. Pictures of WT-EV, Prep1 KO1-EV and Prep1 KO1-Prep1 EBs after 2, 5, 7 and 9 days of differentiation. The scale bars indicate 200μm. The EBs were formed starting from 1000 cells. The histogram to the right shows the number of EBs formed at different differentiation times in the different cell lines. (B) RT-qPCR analysis of <i>Oct4</i>, <i>Gata4</i> and <i>Fgf4</i> RNA in WT-EV, Prep1 KO1-EV and Prep1 KO1-Prep1 ES cells (day 0) and differentiating EBs at day 2, day 5, day 7 and day 9 of differentiation (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0122518#sec009" target="_blank">Methods</a> section). (C) RT-qPCR analysis of <i>Fgfr2</i> and <i>Fgfr3</i> RNA in WT-EV, Prep1 KO1-EV and Prep1 KO1-Prep1 ES cells (day 0) and differentiating EBs at day 2, day 5, day 7 and day 9 of differentiation (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0122518#sec009" target="_blank">Methods</a> section).