Imprinting of PEG3, the human homologue of a mouse gene involved in nurturing behavior

The paternally expressed Peg3 gene in mice encodes an unusual Kruppel-type zinc finger protein implicated in critical cellular and behavioral function s including growth, apoptosis, and maternal nurturing behavior. Methylation and expression analyses were used to determine whether PEG3 on chromosome 19q13.4 is imprinted in humans. The PEG3 promoter is encompassed within a l arge CpG-rich region that is differentially methylated in fetal tissues. Fu rthermore, expression studies demonstrate that PEG3 is ubiquitously imprint ed throughout development and postnatally. Multiple isoforms of the PEG3 ge ne, including a novel transcript, are paternally expressed. These results a re the first to show that human chromosome 19q13.4 contains an imprinted re gion. The imprinted status of PEG3 throughout life coupled with its neural expression and putative roles in regulating cell growth suggests that PEG3 may be a susceptibility locus for cancer as well as neurobehavioral deficit s. (C) 2001 Academic Press.