The Ple15-lacZ plasmid (pEMS1485) was created by inserting the Ple15 MiniPromoter (derived from specific promoter/enhancer/regulatory regions of the human chromosome 8 open reading frame 46 (C8orf46) gene) into the multiple cloning site of the pEMS1313 plasmid vector backbone. This placed the Ple15 MiniPromoter upstream of an intron, a full F5 mutant-frt site, a Kozak consensus sequence, a beta-galactosidase (lacZ) gene, a full wildtype frt site, an SV40 early polyA signal, a human HPRT complementary sequence (containing exon 1, intron 1, exon 2, and part of intron 2), a mouse 3' Hprt homology arm, an I-Sce linearization cut site, and a mouse 5' Hprt homology arm. This Ple15-lacZ construct was targeted as a single copy knock-in to the Hprtb-m3 mutant locus on the X Chromosome via electroporation into mEMS1202 embryonic stem cells. (J:164356)