Transgenic construct used to study the ability of the imprinting control region (ICR) of the mouse H19 gene to act as a silencer. Encodes two divergently transcribed reporters, a mini-w gene driven by its own promoter and a lacZ reporter driven by a minimal eve promoter. A 1260bp fragment from the H19 ICR (from -1.75 to -3.0kb relative to the H19 transcription start site), and a 1026bp fragment containing the iab5 enhancer has been inserted in between the two divergent promoters, such that the iab5 sequence is proximal to the eve-lacZ reporter.