Fig. 1. MADM-based analysis of imprinted Cdkn1c gene function at single-cell level.

a MADM recombination events result in distinct fluorescent labeling of cells containing uniparental disomy (UPD). Yellow cells are control cells, green cells carry maternal uniparental chromosome disomy (matUPD) and red cells contain paternal uniparental chromosome disomy (patUPD). Cdkn1c is expressed from the maternal allele in yellow cells, which resembles the wild-type situation. In green cells (matUPD) Cdkn1c is expressed from both maternal alleles and predicted to result in growth/proliferation disadvantage (expression of two doses of a growth inhibitor). Red cells (patUPD) lack Cdkn1c expression and are expected to show growth/proliferation advantage due to lack of expression of a growth suppressor. b Schematic depicts green (GFP⁺), red (tdT⁺), yellow (GFP⁺/tdT⁺) and unlabeled MADM cells with UPD (red, green) and control cells (yellow, unlabeled). Parental origin of chromosome is indicated (M, maternal; P, paternal). Imprinting status of Cdkn1c (arrow, expression; ball on stick, repression) and predicted expression (0×, 1×, 2×) is indicated. c Relative Cdkn1c expression in matUPD (red bars) and patUPD (blue bars) at E13 and E16. Bars represent mean. *p < 0.05, ***p < 0.001 (Wald test). Data points indicate individual animals (n = 4–7). d MADM-labeling pattern in cerebral cortex of MADM-7 (MADM-7^GT/TG;Emx1^Cre/+) at P21. The parent from which the MADM cassettes were inherited is indicated in the respective genotypes in pink (mother) and blue (father). e Higher magnification of cortical cross-section (boxed area in (d)). f G/R ratio of single MADM-labeled cortical neurons is depicted as geometric mean. Note the equipotency of cells with matUPD and patUPD. Nuclei (d, e) were stained using 4',6-diamidino-2-phenylindole (DAPI, blue). Data points indicating individual animals (n = 3). Source data are provided as a Source Data file. Scale bar, 500 μm (d), 90 μm (e).