A novel long-range enhancer regulates postnatal expression of Zeb2: Implications for Mowat-Wilson syndrome phenotypes

Human Molecular Genetics (Impact Factor: 6.39). 12/2012; 21(26):5429-5442. DOI: 10.1093/hmg/dds389


The zinc-finger, E-box-binding homeobox-2 (Zeb2) gene encodes a SMAD-interacting transcription factor that has diverse roles in development and disease. Mutations at the
hZeb2 locus cause Mowat–Wilson syndrome (MWS), a genetic disorder that is associated with mental retardation and other, case- and
sex-dependent clinical features. Recent studies have detailed microRNA-mediated control of Zeb2, but little is known about the genomic context of this gene or of enhancer sequences that may direct its diverse functions.
Here, we describe a novel transgenic rodent model in which Zeb2 regulatory sequence has been disrupted, resulting in a postnatal developmental phenotype that is autosomal dominant. The
phenotype exhibits a genotype-by-sex interaction and manifests primarily as an acute attenuation of postnatal kidney development
in males. Other aspects of embryonic and neonatal development, including neuronal, are unaffected. The transgene insertion
site is associated with a 12 kb deletion, 1.2 Mb upstream of Zeb2, within a 4.1 Mb gene desert. A conserved sequence, derived from the deleted region, enhanced Zeb2 promoter activity in transcription assays. Tissue and temporal restriction of this enhancer activity may involve postnatal
changes in proteins that bind this sequence. A control human/mouse VISTA enhancer (62 kb upstream of Zeb2) also up-regulated the Zeb2 promoter, providing evidence of a string of conserved distal enhancers. The phenotype arising from deletion of one copy of
the extreme long-range enhancer indicates a critical role for this enhancer at one developmental stage. Haploinsufficiency
of Zeb2 in this developmental context reflects inheritance of MWS and may underlie some sex-dependent, non-neural characteristics
of this human inherited disorder.

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