Presence of Prostaglandin E₂ in Homozygous Lethal Yellow (Aʸ/Aʸ) Mouse Embryos

Abstract

Homozygous lethal yellow (Aʸ/Aʸ) mouse embryos develop with characteristic abnormalities and die before completing implantation. The heterozygous lethal yellow (Aʸ/α) condition is pleiotropic, affecting coat color and fat deposition, causing a diabetes-like syndrome, and shortening life expectancy. Lamoureux and Ong suggest prostaglandin E₂ (PGE₂) as a possible chemical messenger for the agouti locus gene action because prostaglandins are known to be endogenous to normal mouse embryos, involved in pigmentation and the implantation process, and could account for the pleiotropic effects of the lethal yellow gene. As a frist step in evaluating this hypothesis, the purpose of this research was to determine whether or not PGE₂ is present in the cells of homozygous lethal yellow murine embryos. Embryos were collected from heterozygous (Aʸ/α) matings and screened for PGE₂ by immunohistochemical assay. Whereas one-fourth of the embryos were expected to be homozygous for the lethal yellow allele, only 2 of the 15 embryos were positive for PGE₂. The results suggest that the presence of one or more Aʸ genes prevented the detection of PGE₂.