Isolation and partial characterization of proteins involved in maternal transfer of selenium in the western fence lizard (Sceloporus occidentalis).

Selenium from dietary exposure is efficiently transferred from mother to offspring in oviparous vertebrates, where it can cause severe teratogenic effects. We isolated and partially characterized proteins involved in maternal transfer of selenium in the oviparous lizard Sceloporus occidentalis using size-exclusion chromatography, inductively coupled plasma-mass spectrometry, and polyacrylamide gel electrophoresis. Selenium from dietary selenomethionine exposure was incorporated into at least three egg proteins. One of these proteins was lipovitellin. The other two proteins may be part of a previously unknown mechanism of maternal transfer of Se that is independent of vitellogenesis or albumin secretion. Our results suggest at least three pathways for maternal transfer of Se in vertebrates that may vary in importance depending on the species.