Decreasing Wapl dosage partially corrects embryonic growth and brain transcriptome phenotypes in Nipbl +/- embryos.

Cohesin rings interact with DNA and modulate the expression of thousands of genes. NIPBL loads cohesin onto chromosomes, and WAPL takes it off. Haploinsufficiency for causes a developmental disorder, Cornelia de Lange syndrome (CdLS), that is modeled by mice. Mutations in have not been shown to cause disease or gene expression changes in mammals. Here, we show dysregulation of >1000 genes in embryonic mouse brain. The patterns of dysregulation are highly similar in and heterozygotes, suggesting that mutations may also cause human disease. Since WAPL and NIPBL have opposite effects on cohesin's association with DNA, we asked whether decreasing dosage could correct phenotypes seen in mice. Gene expression and embryonic growth are partially corrected, but perinatal lethality is not. Our data are consistent with the view that cohesin dynamics play a key role in regulating gene expression.