Embryonic expression profile of phospholipid hydroperoxide glutathione peroxidase

The selenoenzyme phospholipid hydroperoxide glutathione peroxidase (PHGPx) is indispensable for murine embryonic development; yet, the cellular mechanisms leading to embryonic death around gastrulation are still unclear. To investigate PHGPx expression patterns during embryogenesis, we performed a detailed analysis that revealed a complex expression profile. Up to embryonic day 9.5, PHGPx was ubiquitously expressed, which was, albeit to a lower extent, maintained throughout later stages of embryogenesis. Notably, strong expression was frequently observed in epithelial tissue. A transient increase in PHGPx expression was detected in developing tissues, suggesting a crucial role for PHGPx in proliferation and differentiation. By semi-quantitative RT-PCR analysis we observed that the cytosolic form of PHGPx was present in embryonic and somatic tissues whereas the mitochondrial and nuclear forms were detectable only in testicular tissue. This strongly suggests that it is the cytosolic form of PHGPx that is indispensable for embryonic development.