Transcription profiling in the liver of undernourished male rat offspring reveals altered lipid metabolism pathways and predisposition to hepatic steatosis.

Clinical and animal studies have reported an association between low birth weight and the development of nonalcoholic fatty liver disease (NAFLD) in offspring. Using a model of prenatal maternal 70% food restriction diet (FR30) in the rat, we previously showed that maternal undernutrition predisposes offspring to altered lipid metabolism in adipose tissue, especially on a high-fat (HF) diet. Here, using microarray-based expression profiling combined with metabolic, endocrine, biochemical, histological, and lipidomic approaches, we assessed whether FR30 procedure sensitizes adult male offspring to impaired lipid metabolism in the liver. No obvious differences were noted in the concentrations of triglycerides, cholesterol, and bile acids in the liver of 4-mo-old FR30 rats whichever postweaning diet was used. However, several clues suggest that offspring's lipid metabolism and steatosis are modified by maternal undernutrition. First, lipid composition was changed (i.e., higher total saturated fatty acids and lower elaidic acid) in the liver, whereas larger triglyceride droplets were observed in hepatocytes of undernourished rats. Second, FR30 offspring exhibited long-term impact on hepatic gene expression and lipid metabolism pathways on a chow diet. Although the transcriptome profile was globally modified by maternal undernutrition, cholesterol and bile acid biosynthesis pathways appear to be key targets, indicating that FR30 animals were predisposed to impaired hepatic cholesterol metabolism. Third, the FR30 protocol markedly modifies hepatic gene transcription profiles in undernourished offspring in response to postweaning HF. Overall, FR30 offspring may exhibit impaired metabolic flexibility, which does not enable them to properly cope with postweaning nutritional challenges influencing the development of nonalcoholic fatty liver.

Gestational nutrition 2: gene expression in sheep fetal ovaries exposed to gestational under nutrition.

A number of studies have demonstrated effects of gestational undernutrition on fetal ovarian development and postnatal female fertility. However, the mechanism underlying these effects remains elusive. Using a cohort of animals in which altered gestational nutrition affected indicators of postnatal fertility, this study applies RNAseq to fetal ovaries to identify affected genes and pathways that may underlie the relationship between gestational plane of nutrition and postnatal fertility. Pregnant ewes were exposed to either a maintenance diet or 0.6 of maintenance for the first 55 days of gestation followed by an ad libitum diet. Complementary DNA libraries were constructed from 5 to 6 fetal ovaries from each nutritional group at both days 55 and 75 of gestation and sequenced using Ion Proton. Of approximately 16,000 transcripts, 69 genes were differentially expressed at day 55 and 145 genes differentially expressed at day 75. At both gestational ages, genes expressed preferentially in germ cells were common among the differentially expressed genes. Enriched gene ontology terms included ion transport, nucleic acid binding, protease inhibitor activity and carrier proteins of the albumin family. Affected pathways identified by IPA analysis included LXR/RXR activation, FXR/RXR activation, pathways associated with nitric oxide production and citrullination (by NOS1), vitamin C transport and metabolism and REDOX reactions. The data offer some insights into potential mechanisms underlying the relationship between gestational plane of nutrition and postnatal fertility observed in these animals. In particular, the roles of nitric oxide and protease inhibitors in germ cell development are highlighted and warrant further study.

Placental Development and Nutritional Environment.

The placenta is considered to have developed recently in mammalian evolution. While the fundamental function of the placenta, i.e., providing nutrients and oxygen to the fetus and receiving waste products, is the same in all mammals, the morphology of the placenta varies substantially in a species-dependent manner. Therefore, considerable interest exists in understanding placental development and function in mammals from a molecular biological viewpoint. Numerous recent studies have shown that various environmental factors before and during pregnancy, including nutrition, affect placental formation and function and that alterations in placental formation and function can influence the developing fetus and the offspring after birth. To date, the relationship between nutrition and the placenta has been investigated in several species, various model organisms, and humans. In this chapter, we discuss the current knowledge of the placenta and the epigenome and then highlight the effects of nutrition during pregnancy on the placenta and the fetus and on the offspring after birth.

Perinatal nutrition interacts with genetic background to alter behavior in a parent-of-origin-dependent manner in adult Collaborative Cross mice.

Previous studies in animal models and humans have shown that exposure to nutritional deficiencies in the perinatal period increases the risk of psychiatric disease. Less well understood is how such effects are modulated by the combination of genetic background and parent-of-origin (PO). To explore this, we exposed female mice from 20 Collaborative Cross (CC) strains to protein deficient, vitamin D deficient, methyl donor enriched or standard diet during the perinatal period. These CC females were then crossed to a male from a different CC strain to produce reciprocal F1 hybrid females comprising 10 distinct genetic backgrounds. The adult F1 females were then tested in the open field, light/dark, stress-induced hyperthermia, forced swim and restraint stress assays. Our experimental design allowed us to estimate effects of genetic background, perinatal diet, PO and their interactions on behavior. Genetic background significantly affected all assessed phenotypes. Perinatal diet exposure interacted with genetic background to affect body weight, basal body temperature, anxiety-like behavior and stress response. In 8 of 9 genetic backgrounds, PO effects were observed on multiple phenotypes. Additionally, we identified a small number of diet-by-PO effects on body weight, stress response, anxiety- and depressive-like behavior. Our data show that rodent behaviors that model psychiatric disorders are affected by genetic background, PO and perinatal diet, as well as interactions among these factors.

Fetal and Maternal Genetic Variants Influencing Neonatal Vitamin D Status.

Objective: Several genetic polymorphisms determine vitamin D status. We aimed to estimate the strength of association of established 25-hydroyxvitamin D (25OHD)-associated variants in the mother and in the fetus, with 25OHD concentration in newborn umbilical cord plasma. Methods: We randomly selected 578 mother and child dyads from the prospective Norwegian Mother and Child Cohort study. 25OHD was assayed in maternal samples taken shortly after delivery and in cord samples. We genotyped the mother and child for single nucleotide polymorphisms in or near GC, DHCR7, CYP2R1, and CYP24A1, previously confirmed to be associated with 25OHD, and computed genetic risk score (GRS). The genetic associations were replicated in an independent sample of 594 subjects. Results: Although both fetal and maternal GRS were associated with cord 25OHD, only fetal GRS remained significantly associated with cord 25OHD in a regression model with maternal and fetal GRS simultaneously (1.6 nmol/L per fetal 25OHD-increasing allele; 95% confidence interval, 0.6 to 2.5, P = 0.0001). Two fetal single nucleotide polymorphisms in the GC gene (rs2282679 and rs222040) were the strongest genetic predictors of cord 25OHD [4.0 (2.1 to 5.9) and 3.0 (1.3 to 4.8) nmol/L per fetal allele, P < 0.001], followed by rs12785878 in DHCR7 [2.0 (0.1 to 3.8) nmol/L, P = 0.037]. The independent replication sample gave similar results. With fetal genotype included in a regression model with environmental factors, R2 for cord 25OHD was 0.28. Conclusions: We show that fetal 25OHD-modifying genotype was a stronger predictor of cord 25OHD than corresponding maternal genotype. This raises interesting questions about fetal acquisition and placental transfer of 25OHD.

Maternal exposure to Western diet affects adult body composition and voluntary wheel running in a genotype-specific manner in mice.

Some human diseases, including obesity, Type II diabetes, and numerous cancers, are thought to be influenced by environments experienced in early life, including in utero. Maternal diet during the perinatal period may be especially important for adult offspring energy balance, potentially affecting both body composition and physical activity. This effect may be mediated by the genetic background of individuals, including, for example, potential "protective" mechanisms for individuals with inherently high levels of physical activity or high basal metabolic rates. To examine some of the genetic and environmental factors that influence adult activity levels, we used an ongoing selection experiment with 4 replicate lines of mice bred for high voluntary wheel running (HR) and 4 replicate, non-selected control lines (C). Dams (half HR and half C) were fed a "Western" diet (WD, high in fat and sucrose) or a standard diet (SD) from 2weeks prior to mating until their pups could feed on solid food (14days of age). We analyzed dam and litter characteristics from birth to weaning, and offspring mass and physical activity into adulthood. One male offspring from each litter received additional metabolic and behavioral tests. Maternal WD caused pups to eat solid food significantly earlier for C litters, but not for HR litters (interaction of maternal environment and genotype). With dam mass as a covariate, mean pup mass was increased by maternal WD but litter size was unaffected. HR dams had larger litters and tended to have smaller pups than C dams. Home-cage activity of juvenile focal males was increased by maternal WD. Juvenile lean mass, fat mass, and fat percent were also increased by maternal WD, but food consumption (with body mass as a covariate) was unaffected (measured only for focal males). Behavior in an elevated plus maze, often used to indicate anxiety, was unaffected by maternal WD. Maximal aerobic capacity (VO2max) was also unaffected by maternal WD, but HR had higher VO2max than C mice. Adult lean, fat, and total body masses were significantly increased by maternal WD, with greater increase for fat than for lean mass. Overall, no aspect of adult wheel running (total distance, duration, average running speed, maximum speed) or home-cage activity was statistically affected by maternal WD. However, analysis of the 8 individual lines revealed that maternal WD significantly increased wheel running in one of the 4 HR lines. On average, all groups lost fat mass after 6days of voluntary wheel running, but the absolute amount lost was greater for mice with maternal WD resulting in no effect of maternal WD on absolute or % body fat after wheel access. All groups gained lean and total body mass during wheel access, regardless of maternal WD or linetype. Measured after wheel access, circulating leptin, adiponectin, and corticosterone concentrations were unaffected by maternal WD and did not differ between HR and C mice. With body mass as a covariate, heart ventricle mass was increased by maternal WD in both HR and C mice, but fat pads, liver, spleen, and brain masses were unaffected. As found previously, HR mice had larger brains than C mice. Body mass of grand-offspring was unaffected by grand-maternal WD, but grand-offspring wheel running was significantly increased for one HR line and decreased for another HR line by grand-maternal WD. In summary, maternal Western diet had long-lasting and general effects on offspring adult morphology, but effects on adult behavior were limited and contingent on sex and genetic background.

The effect of iron deficiency on the temporal changes in the expression of genes associated with fat metabolism in the pregnant rat.

Iron is essential for the oxidative metabolism of lipids. Lipid metabolism changes during gestation to meet the requirements of the growing fetus and to prepare for lactation. The temporal effects of iron deficiency during gestation were studied in female rats fed complete or iron-deficient diets. Plasma triglycerides were elevated in the iron-deficient group throughout gestation. There were time-dependent changes in the triglyceride content of the maternal liver, falling at the midpoint of gestation and then increasing on d21.5. Compared to the control, triglycerides in the maternal liver were not different in the iron-deficient group prior to pregnancy and on d12.5, but were markedly reduced by d21.5. The abundance of mRNAs in the maternal liver suggests that lipogenesis is unchanged and beta-oxidation is reduced on d21.5 by iron deficiency. On d21.5 of gestation, the expression of placental lipase was unchanged by iron deficiency, however, the abundance of mRNAs for SREBP-1c, FABP4 were reduced, suggesting that there were changes in fatty acid handling. In the fetal liver, iron deficiency produced a marked decrease in the abundance of the L-CPT-1 mRNA, suggesting that beta-oxidation is reduced. This study shows that the major effect of iron deficiency on maternal lipid metabolism occurs late in gestation and that perturbed lipid metabolism may be a common feature of models of fetal programming.

Developmental Origins of Disease - Crisis Precipitates Change.

The concept of developmental origins of diseases has gained a huge interest in recent years and is a constantly emerging scientific field. First observations hereof originated from epidemiological studies, linking impaired birth outcomes to adult chronic, noncommunicable disease. By now there is a considerable amount of both epidemiological and experimental evidence highlighting the impact of early life events on later life disease susceptibility. Albeit far from being completely understood, more recent studies managed to elucidate underlying mechanisms, with epigenetics having become almost synonymous with developmental programming. The aim of this review was to give a comprehensive overview of various aspects and mechanisms of developmental origins of diseases. Starting from initial research foci mainly centered on a nutritionally impaired intrauterine environment, more recent findings such as postnatal nutrition, preterm birth, paternal programming and putative interventional approaches are summarized. The review outlines general underlying mechanisms and particularly discusses mechanistic explanations for sexual dimorphism in developmental programming. Furthermore, novel hypotheses are presented emphasizing a non-mendelian impact of parental genes on the offspring's phenotype.

High Gestational Folic Acid Supplementation Alters Expression of Imprinted and Candidate Autism Susceptibility Genes in a sex-Specific Manner in Mouse Offspring.

Maternal nutrients play critical roles in modulating epigenetic events and exert long-term influences on the progeny's health. Folic acid (FA) supplementation during pregnancy has decreased the incidence of neural tube defects in newborns, but the influence of high doses of maternal FA supplementation on infants' brain development is unclear. The present study was aimed at investigating the effects of a high dose of gestational FA on the expression of genes in the cerebral hemispheres (CHs) of 1-day-old pups. One week prior to mating and throughout the entire period of gestation, female C57BL/6J mice were fed a diet, containing FA at either 2 mg/kg (control diet (CD)) or 20 mg/kg (high maternal folic acid (HMFA)). At postnatal day 1, pups from different dams were sacrificed and CH tissues were collected. Quantitative RT-PCR and Western blot analysis confirmed sex-specific alterations in the expression of several genes that modulate various cellular functions (P < 0.05) in pups from the HMFA group. Genomic DNA methylation analysis showed no difference in the level of overall methylation in pups from the HMFA group. These findings demonstrate that HMFA supplementation alters offsprings' CH gene expression in a sex-specific manner. These changes may influence infants' brain development.

In utero exposure to a maternal high-fat diet alters the epigenetic histone code in a murine model.

OBJECTIVE: Data from animal models show that in utero exposure to a maternal high-fat diet (HFD) renders susceptibility of these offspring to the adult onset of metabolic syndrome. We and others have previously shown that epigenetic modifications to histones may serve as a molecular memory of the in utero exposure, rendering the risk of adult disease. Because mice heterozygous for the Glut4 gene (insulin sensitive glucose transporter) born to wild-type (WT) mothers demonstrate exacterbated metabolic syndrome when exposed to an HFD in utero, we sought to analyze the genome-wide epigenetic changes that occur in the fetal liver in susceptible offspring. STUDY DESIGN: WT and Glut4(+/-) (G4(+/-)) offspring of WT mothers that were exposed either to a control or an HFD in utero were studied. Immunoblotting was used to measure hepatic histone modifications of fetal and 5-week animals. Chromatin immunoprecipitation (ChIP) followed by hybridization to chip arrays (ChIP-on-chip) was used to detect genome-wide changes of histone modifications with HFD exposure. RESULTS: We found that levels of hepatic H3K14ac and H3K9me3 significantly increased with HFD exposure in WT and G4(+/-) fetal and 5-week offspring. Pathway analysis of our ChIP-on-chip data revealed differential H3K14ac and H3K9me3 enrichment along pathways that regulate lipid metabolism, specifically in the promoter regions of Pparg, Ppara, Rxra, and Rora. CONCLUSION: We conclude that HFD exposure in utero is associated with functional alterations to fetal hepatic histone modifications in both WT and G4(+/-) offspring, some of which persist up to 5 weeks of age.

A calcium-deficient diet in pregnant, nursing rats induces hypomethylation of specific cytosines in the 11ß-hydroxysteroid dehydrogenase-1 promoter in pup liver.

Prenatal undernutrition affects offspring phenotype via changes in the epigenetic regulation of specific genes. We hypothesized that pregnant females that were fed a calcium (Ca)-deficient diet would have offspring with altered hepatic glucocorticoid-related gene expression and altered epigenetic gene regulation. Female Wistar rats ate either a Ca-deficient or control diet from 3 weeks before conception to 21 days after parturition. Pups were allowed to nurse from their original mothers and then euthanized on day 21. Methylation of individual cytosine-guanine dinucleotides in the phosphoenolpyruvate carboxykinase (Pck1), peroxisome proliferator-activated receptor α (Ppara), glucocorticoid receptor (Nr3c1), 11ß-hydroxysteroid dehydrogenase-1 (Hsd11b1), and 11ß-hydroxysteroid dehydrogenase-2 (Hsd11b2) promoters was measured in liver tissue using pyrosequencing. For each gene, quantitative real-time polymerase chain reaction was used to assess mRNA levels in liver tissue. Overall Hsd11b1 methylation was lower in the Ca-deficient group than in the control group; however, overall methylation of each other gene did not differ between groups. Serum corticosterone levels in male pups from Ca-deficient dams were higher than those in control pups. Expression of Pck1 and Nr3c1 was lower in the Ca-deficient group than in the control group. A Ca-deficient diet for a dam during gestation and early nursing may alter glucocorticoid metabolism and lead to higher intracellular glucocorticoid concentrations in the hepatic cells of her offspring; moreover, this abnormal glucocorticoid metabolism may induce the metabolic complications that are associated with Ca deficiency. These findings indicated that prenatal nutrition affected glucocorticoid metabolism in offspring in part by affecting the epigenome of offspring.

Involvement of renal corpuscle microRNA expression on epithelial-to-mesenchymal transition in maternal low protein diet in adult programmed rats.

Prior study shows that maternal protein-restricted (LP) 16-wk-old offspring have pronounced reduction of nephron number and arterial hypertension associated with unchanged glomerular filtration rate, besides enhanced glomerular area, which may be related to glomerular hyperfiltration/overflow and which accounts for the glomerular filtration barrier breakdown and early glomerulosclerosis. In the current study, LP rats showed heavy proteinuria associated with podocyte simplification and foot process effacement. TGF-ß1 glomerular expression was significantly enhanced in LP. Isolated LP glomeruli show a reduced level of miR-200a, miR-141, miR-429 and ZEB2 mRNA and upregulated collagen 1α1/2 mRNA expression. By western blot analyzes of whole kidney tissue, we found significant reduction of both podocin and nephrin and enhanced expression of mesenchymal protein markers such as desmin, collagen type I and fibronectin. From our present knowledge, these are the first data showing renal miRNA modulation in the protein restriction model of fetal programming. The fetal-programmed adult offspring showed pronounced structural glomerular disorders with an accentuated and advanced stage of fibrosis, which led us to state that the glomerular miR-200 family would be downregulated by TGF-ß1 action inducing ZEB 2 expression that may subsequently cause glomeruli epithelial-to-mesenchymal transition.

The obstetric origins of health for a lifetime.

There is a new "developmental" model for the origins of a wide range of chronic diseases. Under this model the causes to be identified are linked to normal variations in fetoplacental development. These variations are thought to lead to variations in the supply of nutrients to the baby that permanently alter gene expression, a process known as "programming." According to the developmental model variations in the processes of development program the function of a few key systems that are linked to disease, including the immune system, antioxidant defenses, inflammatory responses, and the number and quality of stem cells.

Transcriptomic and epigenetic changes in the hypothalamus are involved in an increased susceptibility to a high-fat-sucrose diet in prenatally stressed female rats.

Disturbances in the prenatal period are linked to metabolic disorders in adulthood, implying the hypothalamic systems of appetite and energy balance regulation. In order to analyze the central effects of a high-fat-sucrose (HFS) diet in prenatally stressed (PNS) female adult rats, Wistar dams were exposed to chronic-mild-stress during the third week of gestation and were then compared with unstressed controls. Adult female offspring were fed a chow or HFS diet for 10 weeks. Changes in body weight, adiposity as well as expression and methylation levels of selected hypothalamic genes were analyzed. PNS induced lower birthweight and body length with no changes in body fat mass. After the HFS diet, the expected overweight model was observed accompanied by higher adiposity and insulin resistance, which was worsened by PNS. The stress model induced higher energy intake in adulthood. Hypothalamic gene expression analysis revealed that the HFS diet decreased Slc6a3 (dopamine active transporter), NPY (neuropeptide Y) and IR (insulin receptor) and increased POMC (pro-opiomelanocortin). Hypothalamic DNA methylation levels in the promoter region of Slc6a3 revealed that Slc6a3 was hypermethylated by the HFS diet in CpG site -53 bp to the transcription start site. HFS diet also hypermethylated CpG site -167 bp of the POMC promoter only in nonstressed animals. No correlations were found between gene expression and DNA methylation levels. These results imply that early-life stress in females increased predisposition to diet-induced obesity in adulthood.

Epigenetics: are there implications for personalised nutrition?

PURPOSE OF REVIEW: This review critically evaluates recent advances in understanding the role of epigenetics in nutrition. Findings from animal models and human cohorts are discussed in the context of whether or not epigenetics may be an important factor in the progress towards the goal of personalised nutrition. RECENT FINDINGS: Maternal dietary fat, folic acid, protein and total energy intakes induce altered epigenetic regulation of specific genes in the offspring which are associated with altered tissue function. Passage of induced phenotypic and epigenetic traits between generations involves intergenerational modifications in the interaction between maternal phenotype and environment. The methylation of specific CpG loci in fetal tissues is associated with differential future risk of type 2 diabetes mellitus, and variation in adiposity and height. Methylation of specific CpGs in adult blood also marks differential risk of type 2 diabetes mellitus and breast cancer. Exercise induces acute changes in the methylation of genes in muscle. SUMMARY: Recent advances indicate that epigenetic variation is an important influence on interactions between nutrients and the genome, which modify disease risk. In contrast to the interaction between nutrition and gene polymorphisms, epigenetic variation can be modified by nutritional interventions to improve health outcomes.

Prenatal nutrition, epigenetics and schizophrenia risk: can we test causal effects?

We posit that maternal prenatal nutrition can influence offspring schizophrenia risk via epigenetic effects. In this article, we consider evidence that prenatal nutrition is linked to epigenetic outcomes in offspring and schizophrenia in offspring, and that schizophrenia is associated with epigenetic changes. We focus upon one-carbon metabolism as a mediator of the pathway between perturbed prenatal nutrition and the subsequent risk of schizophrenia. Although post-mortem human studies demonstrate DNA methylation changes in brains of people with schizophrenia, such studies cannot establish causality. We suggest a testable hypothesis that utilizes a novel two-step Mendelian randomization approach, to test the component parts of the proposed causal pathway leading from prenatal nutritional exposure to schizophrenia. Applied here to a specific example, such an approach is applicable for wider use to strengthen causal inference of the mediating role of epigenetic factors linking exposures to health outcomes in population-based studies.

Prenatal famine and genetic variation are independently and additively associated with DNA methylation at regulatory loci within IGF2/H19.

Both the early environment and genetic variation may affect DNA methylation, which is one of the major molecular marks of the epigenome. The combined effect of these factors on a well-defined locus has not been studied to date. We evaluated the association of periconceptional exposure to the Dutch Famine of 1944-45, as an example of an early environmental exposure, and single nucleotide polymorphisms covering the genetic variation (tagging SNPs) with DNA methylation at the imprinted IGF2/H19 region, a model for an epigenetically regulated genomic region. DNA methylation was measured at five differentially methylated regions (DMRs) that regulate the imprinted status of the IGF2/H19 region. Small but consistent differences in DNA methylation were observed comparing 60 individuals with periconceptional famine exposure with unexposed same-sex siblings at all IGF2 DMRs (P(BH)<0.05 after adjustment for multiple testing), but not at the H19 DMR. IGF2 DMR0 methylation was associated with IGF2 SNP rs2239681 (P(BH) = 0.027) and INS promoter methylation with INS SNPs, including rs689, which tags the INS VNTR, suggesting a mechanism for the reported effect of the VNTR on INS expression (P(BH) = 3.4 × 10(-3)). Prenatal famine and genetic variation showed similar associations with IGF2/H19 methylation and their contributions were additive. They were small in absolute terms (<3%), but on average 0.5 standard deviations relative to the variation in the population. Our analyses suggest that environmental and genetic factors could have independent and additive similarly sized effects on DNA methylation at the same regulatory site.

Effect of maternal dietary energy types on placenta nutrient transporter gene expressions and intrauterine fetal growth in rats.

OBJECTIVE: The objectives of this study were to investigate the effects of maternal dietary energy types on the mRNA expressions of the placental nutrient transporter and intrauterine fetal growth and to examine whether altered intrauterine fetal growth could be associated with different gene expressions relating to fetal energy metabolism and DNA methylation. METHODS: Seventy-two 3-mo-old rats were allocated to one of four groups: low fat/low fiber (L-L), low fat/high fiber, high fat/low fiber (H-L), or high fat/high fiber. Rats were fed the treatment diets 4 wk before mating and continued in pregnancy until sample collections were obtained on days 13.5 and 17.5 of pregnancy. RESULTS: The fetal weight in the L-L group was significantly lower than that in the H-L group (P < 0.05). The placental nutrient transporter mRNA expressions of glucose transporter-3 (Slc2a3) and cationic amino acid transporter-1 (Slc7a1) in the L-L group with a decreased fetal weight were downregulated compared with that in the H-L group with an increased fetal weight. However, placental Slc2a1 and the system A amino acid transporter gene Slc38a4 mRNA expressions were adaptively upregulated by the L-L diet with a decreased fetal weight (P < 0.05). For the placental imprinted gene Igf-2 and H19 expressions, lower Igf-2 and higher H19 expressions were associated with the decreased fetal growth in the L-L group compared with the H-L group with an increased fetal weight. Different fetal growth was associated with different DNA methyltransferase-1 and methyltransferase-3a expressions (P > 0.05) and energy metabolism-related genes. CONCLUSION: Collectively, these results demonstrated that intrauterine fetal growth could be affected by different energy intake types through placenta nutrient transporter gene expressions, and different fetal growths were associated with altered fetal genes related to DNA methylation and energy metabolism.

Effect of gestational protein deficiency and excess on hepatic expression of genes related to cell cycle and proliferation in offspring from late gestation to finishing phase in pig.

Maternal diet during gestation is known to affect offspring phenotype induction. In the present study the influence of maternal protein restriction and excess during gestation on offspring candidate gene expression was analysed. German Landrace gilts were fed control, low protein (LP) or high protein (HP) diet throughout gestation (n = 18 per diet group). After birth piglets were cross-fostered and lactated by control diet fed nursing sows. Samples of offspring liver tissue were taken at foetal, newborn, weaning and finishing phase (n = 16, respectively). Transcript amount of selected candidate genes related to cell cycle and cell proliferation was estimated by quantitative real-time PCR. Maternal protein restriction influenced gene expression of candidate genes CCND2, GADD45B, GALK1, GSTP1, MARCKS, MGMT, NEAT1, PSEN1, SNX1 and TRPM7 in liver from foetuses, newborn piglets, weaned and/or finisher pigs. In the offspring of mothers fed a HP diet expression of target genes was affected exclusively in finisher pigs showing increased transcript amount of CCND2, GALK1, MARCKS, SNX1 and TRPM7. The results of the present study clearly show a long-lasting impact of the maternal protein supply during gestation on offspring candidate genes. Remarkably, effects of gestational HP diet became evident in finisher pigs while LP supply already alters genes expression in foetal tissue. Thus it is suggested that LP and HP supply affect the offspring in utero by different physiological mechanisms with the consequence of late effects in case of prenatal protein excess in contrast to early effects in case of protein restriction.