Identification of Meg3 splice variants. (A) Schematic illustration of the Meg3 gene exon structure. Exons found in all Meg3 isoforms are shown in white, variable exons are shown in black. The location of the primers used to detect the different Meg3 isoforms are marked by arrows. (B) GCTSCs were cultured with or without the addition of Aza and PBA before Meg3 splice variants were amplified by PCR using primers located in different exons. PCR products were separated on a 1.6% agarose gel. Untreated MSCs served as controls. The structure of the main transcript is indicated. Additional splice variants appear as larger transcripts above the main product.