Differential gene profile of resorbed embryos following paternal tamoxifen treatment

Studies from our laboratory have demonstrated that treatment of adult male rats with tamoxifen, a selective estrogen receptor modulator, at a dose of 0.4 mg/kg/day for 60 days resulted in an increase in post-implantation loss at around mid gestation. The present study was done to assess global gene expression profile using Agilent Rat Whole Genome Microarray slides. Differential gene expression profile of resorbed to normal embryos at embryonic day (E) 11 and 13 was studied to identify the causes of resorption. Gene Ontology classification based on biological function revealed significant down regulation of genes associated with development, differentiation, metabolism, transcription, chromatin binding and cell cycle in the resorbed embryos from both the groups at E13. Genes associated with immune response, inflammatory response and angiogenesis were found to be up regulated in the resorbed embryos. Temporal analysis at E11 in the treated resorbed embryos revealed no increase in immune response and inflammation associated genes as seen on E13, indicative of this being a secondary effect. Down regulation of genes associated with development, differentiation, metabolism, transcription, chromatin binding, cell cycle was also evident on E11 in the resorbed embryos. Differential gene expression profile also revealed stochastic expression of imprinted genes, known to modulate embryo-placental growth namely Dlk1, p57, Mash2, Peg3, Lot1 etc. in the resorbed embryos as compared to the normal ones.