Fig 3. Formation of circPeg3 in various mutant alleles.

(A) The gel image represents the results of a nested PCR amplifying circPeg3 from a set of cDNA that have been derived from various mutant alleles. (B) Schematic representation of the mutant alleles used for the current study. The exons are indicated with black vertical lines, while the circE exon is indicated with a green vertical line. The 4-kb genomic region corresponding to the Peg3-DMR is deleted in the KO2 allele, which is indicated with a parenthesis. In the CoKO allele, a 7-kb expression cassette containing the β-galactosidase and neomycin resistance genes with Poly-A tails is inserted into the 5th intron, which is indicated with two open boxes. In the DelKO allele, the 6th exon is deleted as indicated with a parenthesis. In the Invert allele, the 4-kb Peg3-DMR is inverted relative to the orientation of the surrounding genomic regions.