The mouse glutathione peroxidase Gpx2 gene maps to chromosome 12; its pseudogene Gpx2-ps maps to chromosome 7.
The GPX2 gene codes for GSHPx-GI, a glutathione peroxidase whose mRNA is readily detectable in the gastrointestinal tract. Although GPX2 is a single gene in humans, there are two genes in the mouse genome with homology to GPX2. By analyzing a panel of mouse interspecies DNA from the Jackson Laboratory's backcross resource, we have chromosomally mapped these two genes. One was mapped to the central region of mouse chromosome 12 between D12Mit4 and D12Mit5, near fos and Tgfb3. This region is homologous to human 14q24.1, where human GPX2 has been mapped, and most likely represents the functional mouse Gpx2 gene. The other Gpx2-like gene was mapped to mouse chromosome 7 between Pcsk3 and Hbb. We have isolated the latter gene from a P1 phage library. Its pseudogene nature is revealed by the sequence analysis: (a) it is intronless; (b) it has a single nucleotide deletion in the coding region; and (c) it has a poly(A) tail at its 3'-untranslated region.