title: Imprinted gene expression in the rat embryo-fetal axis is altered in response to periconceptional maternal low protein diet.
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.
authors.affiliation: School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX, UK. wyk@soton.ac.uk
authors.forename: Wing Yee
authors.initials: WY
authors.lastname: Kwong
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Miller
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ursell
authors.forename: Arthur E
authors.initials: AE
authors.lastname: Wild
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Wilkins
authors.forename: Clive
authors.initials: C
authors.lastname: Osmond
authors.forename: Fred W
authors.initials: FW
authors.lastname: Anthony
authors.forename: Tom P
authors.initials: TP
authors.lastname: Fleming
mesh_terms: D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000378:metabolism*; D018899:CpG Islands; D019175:DNA Methylation; D018753:Diet, Protein-Restricted; D047108:Embryonic Development / Q000502:physiology; D004958:Estradiol / Q000097:blood; D005260:Female; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D018392:Genomic Imprinting; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D008099:Liver / Q000378:metabolism; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D008969:Molecular Sequence Data; D010920:Placenta / Q000502:physiology; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D017527:Receptor, IGF Type 2 / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012737:Sex Factors
chemical_list: C094335:H19 long non-coding RNA; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D017527:Receptor, IGF Type 2; D011374:Progesterone; D004958:Estradiol; D007335:Insulin-Like Growth Factor II