ABSTRACT
In our previous study, we have shown that maternal low protein diet (LPD, 9% casein vs 18% casein control) fed exclusively during the rat preimplantation period (0-4.25 day postcoitum) induced low birth weight, altered postnatal growth and hypertension in a gender-specific manner. In this study, we investigated the effect of maternal LPD restricted only to the preimplantation period (switched diet) or provided throughout gestation on fetal growth and imprinted gene expression in blastocyst and fetal stages of development. Male, but not female, blastocysts collected from LPD dams displayed a significant reduction (30%) in H19 mRNA level. A significant reduction in H19 (9.4%) and Igf2 (10.9%) mRNA was also observed in male, but not in female, fetal liver at day 20 postcoitum in response to maternal LPD restricted to the preimplantation period. No effect on the blastocyst expression of Igf2R was observed in relation to maternal diet. The reduction in H19 mRNA expression did not correlate with an observed alteration in DNA methylation at the H19 differentially methylated region in fetal liver. In contrast, maternal LPD throughout 20 days of gestation did not affect male or female H19 and Igf2 imprinted gene expression in fetal liver. Neither LPD nor switched diet treatments affected H19 and Igf2 imprinted gene expression in day 20 placenta. Our findings demonstrate that one contributor to the alteration in postnatal growth induced by periconceptional maternal LPD may derive from a gender-specific programming of imprinted gene expression originating within the preimplantation embryo itself.
Subject(s)
Blastocyst/metabolism , Diet, Protein-Restricted , Gene Expression Regulation, Developmental , Genomic Imprinting , Maternal Nutritional Physiological Phenomena , Animals , Base Sequence , CpG Islands , DNA Methylation , Embryonic Development/physiology , Estradiol/blood , Female , Gene Expression , Insulin-Like Growth Factor II/genetics , Liver/metabolism , Male , Molecular Sequence Data , Placenta/physiology , Pregnancy , Progesterone/blood , RNA, Long Noncoding , RNA, Untranslated/analysis , Rats , Rats, Wistar , Receptor, IGF Type 2/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sex FactorsABSTRACT
Expression of agouti-related peptide, neuropeptide Y, pro-opiomelanocortin and leptin receptor isoforms were found in fetal mouse brain at embryonic day 12 (E12). Levels of expression for these genes were altered in brains of E12 fetuses from pregnant dams on a protein-restricted diet, suggesting that the fetal brain is responsive to changes in maternal nutrition prior to birth.
