1 260 92 ADVANCES IN RESEARCH INTO GAMETE AND EMBRYO-FETAL ORIGINS OF ADULT DISEASES. THE FETAL AND INFANT ORIGINS OF ADULT DISEASE HYPOTHESIS PROPOSED THAT THE ROOTS OF ADULT CHRONIC DISEASE LIE IN THE EFFECTS OF ADVERSE ENVIRONMENTS IN FETAL LIFE AND EARLY INFANCY. IN ADDITION TO THE FETAL PERIOD, FERTILIZATION AND EARLY EMBRYONIC STAGES, THE CRITICAL TIME WINDOWS OF EPIGENETIC REPROGRAMMING, RAPID CELL DIFFERENTIATION AND ORGANOGENESIS, ARE THE MOST SENSITIVE STAGES TO ENVIRONMENTAL DISTURBANCES. COMPARED WITH EMBRYO AND FETAL DEVELOPMENT, GAMETOGENESIS AND MATURATION TAKE DECADES AND ARE MORE VULNERABLE TO POTENTIAL DAMAGE FOR A LONGER EXPOSURE PERIOD. THEREFORE, WE SHOULD SHIFT THE FOCUS OF ADULT DISEASE OCCURRENCE AND PATHOGENESIS FURTHER BACK TO GAMETOGENESIS AND EMBRYONIC DEVELOPMENT EVENTS, WHICH MAY RESULT IN INTERGENERATIONAL, EVEN TRANSGENERATIONAL, EPIGENETIC RE-PROGRAMMING WITH TRANSMISSION OF ADVERSE TRAITS AND CHARACTERISTICS TO OFFSPRING. HERE, WE FOCUS ON THE RESEARCH PROGRESS RELATING TO DISEASES THAT ORIGINATED FROM EVENTS IN THE GAMETES AND EARLY EMBRYOS AND THE POTENTIAL EPIGENETIC MECHANISMS INVOLVED. 2019 2 1930 33 ENVIRONMENTAL EXPOSURES AROUND CONCEPTION: DEVELOPMENTAL PATHWAYS LEADING TO LIFETIME DISEASE RISK. ENVIRONMENT AROUND CONCEPTION CAN INFLUENCE THE DEVELOPMENTAL PROGRAMME WITH LASTING EFFECTS ON GESTATIONAL AND POSTNATAL PHENOTYPE AND WITH CONSEQUENCES FOR ADULT HEALTH AND DISEASE RISK. PERI-CONCEPTION EXPOSURE COMPRISES A CRUCIAL PART OF THE 'DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE' (DOHAD) CONCEPT. IN THIS REVIEW, WE CONSIDER THE EFFECTS OF MATERNAL UNDERNUTRITION EXPERIENCED DURING THE PERI-CONCEPTION PERIOD IN SELECT HUMAN MODELS AND IN A MOUSE EXPERIMENTAL MODEL OF PROTEIN RESTRICTION. HUMAN DATASETS INDICATE THAT MACRONUTRIENT DEPRIVATION AROUND CONCEPTION AFFECT THE EPIGENOME, WITH ENDURING EFFECTS ON CARDIOMETABOLIC AND NEUROLOGICAL HEALTH. THE MOUSE MODEL, COMPRISING MATERNAL LOW PROTEIN DIET EXCLUSIVELY DURING THE PERI-CONCEPTION PERIOD, HAS REVEALED A STEPWISE PROGRESSION IN ALTERED DEVELOPMENTAL PROGRAMMING FOLLOWING INDUCTION THROUGH MATERNAL METABOLITE DEFICIENCY. THIS PROGRESSION INCLUDES DIFFERENTIAL EFFECTS IN EXTRA-EMBRYONIC AND EMBRYONIC CELL LINEAGES AND TISSUES, LEADING TO MALADAPTATION IN THE GROWTH TRAJECTORY AND INCREASED CHRONIC DISEASE COMORBIDITIES. THE TIMELINE EMBRACES AN ARRAY OF MECHANISMS ACROSS NUTRIENT SENSING AND SIGNALLING, CELLULAR, METABOLIC, EPIGENETIC AND PHYSIOLOGICAL PROCESSES WITH A COORDINATING ROLE FOR MTORC1 SIGNALLING PROPOSED. EARLY EMBRYOS APPEAR ACTIVE PARTICIPANTS IN ENVIRONMENTAL SENSING TO OPTIMISE THE DEVELOPMENTAL PROGRAMME FOR SURVIVAL BUT WITH THE TRADE-OFF OF LATER DISEASE. SIMILAR ADVERSE HEALTH OUTCOMES MAY DERIVE FROM OTHER PERI-CONCEPTION ENVIRONMENTAL EXPERIENCES, INCLUDING MATERNAL OVERNUTRITION, MICRONUTRIENT AVAILABILITY, POLLUTANT EXPOSURE AND ASSISTED REPRODUCTIVE TREATMENTS (ART) AND SUPPORT THE NEED FOR PRECONCEPTION HEALTH BEFORE PREGNANCY. 2021 3 1488 29 DNA DAMAGE RECOGNITION IN THE RAT ZYGOTE FOLLOWING CHRONIC PATERNAL CYCLOPHOSPHAMIDE EXPOSURE. THE DETRIMENTAL EFFECTS OF PRECONCEPTIONAL PATERNAL EXPOSURE TO THE ALKYLATING ANTICANCER AGENT, CYCLOPHOSPHAMIDE, INCLUDE ABERRANT EPIGENETIC PROGRAMMING, DYSREGULATED ZYGOTIC GENE ACTIVATION, AND ABNORMALITIES IN THE OFFSPRING THAT ARE TRANSMITTED TO THE NEXT GENERATION. THE ADVERSE DEVELOPMENTAL CONSEQUENCES OF GENOMIC INSTABILITIES TRANSMITTED VIA THE SPERMATOZOON EMPHASIZE THE NEED TO ELUCIDATE THE MECHANISMS BY WHICH THE EARLY EMBRYO RECOGNIZES DNA DAMAGE IN THE PATERNAL GENOME. LITTLE INFORMATION EXISTS ON DNA DAMAGE DETECTION IN THE ZYGOTE. WE ASSESSED THE IMPACT OF PATERNAL CYCLOPHOSPHAMIDE EXPOSURE ON PHOSPHORYLATED H2AX (GAMMAH2AX) AND POLY(ADP-RIBOSE) POLYMERASE-1(PARP-1), BIOMARKERS OF DNA DAMAGE, TO DETERMINE THE CAPACITY IN THE RAT ZYGOTE TO RECOGNIZE GENOMIC DAMAGE AND INITIATE A RESPONSE TO DNA LESIONS. AN AMPLIFIED BIPHASIC GAMMAH2AX RESPONSE WAS TRIGGERED IN THE PATERNAL PRONUCLEUS IN ZYGOTES SIRED BY DRUG-TREATED MALES; THE MATERNAL GENOME WAS NOT AFFECTED. PARP-1 IMMUNOREACTIVITY WAS SUBSTANTIALLY ELEVATED IN BOTH PARENTAL GENOMES, COINCIDENT WITH THE SECOND PHASE OF GAMMAH2AX INDUCTION IN EMBRYOS SIRED BY CYCLOPHOSPHAMIDE-EXPOSED SPERMATOZOA. THUS, PATERNAL EXPOSURE TO A DNA DAMAGING AGENT RAPIDLY ACTIVATES SIGNALS IMPLEMENTAL FOR DNA DAMAGE RECOGNITION IN THE ZYGOTE. INEFFICIENT REPAIR OF DNA LESIONS MAY LEAD TO PERSISTENT ALTERATIONS OF THE HISTONE CODE AND CHROMATIN INTEGRITY, RESULTING IN ABERRANT EMBRYOGENESIS. WE PROPOSE THAT THE RESPONSE OF THE EARLY EMBRYO TO DISTURBANCES IN SPERMATOZOAL GENOMIC INTEGRITY PLAYS A VITAL ROLE IN DETERMINING ITS OUTCOME. 2007 4 4941 26 PATERNAL OBESITY, INTERVENTIONS, AND MECHANISTIC PATHWAYS TO IMPAIRED HEALTH IN OFFSPRING. BACKGROUND: THE GLOBAL RATES OF MALE OVERWEIGHT/OBESITY ARE RISING, APPROACHING 70% OF THE TOTAL ADULT POPULATION IN WESTERN NATIONS. OVERWEIGHT/OBESITY INCREASES THE RISK OF CHRONIC DISEASES; HOWEVER, THERE IS INCREASING AWARENESS THAT MALE OBESITY NEGATIVELY IMPACTS FERTILITY, SUBSEQUENT PREGNANCY, AND THE OFFSPRING HEALTH BURDEN. DEVELOPMENTAL PROGRAMMING IS WELL DEFINED IN MOTHERS; HOWEVER, IT IS BECOMING INCREASINGLY EVIDENT THAT DEVELOPMENTAL PROGRAMMING CAN BE PATERNALLY INITIATED AND MEDIATED THROUGH PATERNAL OBESITY. KEY MESSAGES: BOTH HUMAN AND RODENT MODELS HAVE ESTABLISHED THAT PATERNAL OBESITY IMPAIRS SEX HORMONES, BASIC SPERM FUNCTION, AND MOLECULAR COMPOSITION. THIS RESULTS IN PERTURBED EMBRYO DEVELOPMENT AND HEALTH AND AN INCREASED SUBSEQUENT OFFSPRING DISEASE BURDEN IN BOTH SEXES. THE REVERSIBILITY OF OBESITY-INDUCED PARENTAL PROGRAMMING HAS ONLY RECENTLY RECEIVED ATTENTION. PROMISING RESULTS IN ANIMAL MODELS UTILIZING DIET AND EXERCISE INTERVENTIONS HAVE SHOWN IMPROVEMENTS IN SPERM FUNCTION AND MOLECULAR COMPOSITION, RESULTING IN RESTORATIONS OF BOTH EMBRYO AND FETAL HEALTH AND SUBSEQUENT MALE OFFSPRING FERTILITY. THE DIRECT MODE FOR PATERNAL INHERITANCE IS LIKELY MEDIATED VIA SPERMATOZOA. WE PROPOSE TWO MAIN THEORIES FOR THE ORIGIN OF MALE OBESITY-INDUCED PATERNAL PROGRAMMING: (1) ACCUMULATION OF SPERM DNA DAMAGE RESULTING IN DE NOVO MUTATIONS IN THE EMBRYO AND (2) CHANGES IN SPERM EPIGENETIC MARKS (MICRORNA, METHYLATION, OR ACETYLATION) ALTERING THE ACCESS, TRANSCRIPTION, AND TRANSLATION OF PATERNALLY DERIVED GENES DURING EARLY EMBRYOGENESIS. CONCLUSIONS: PATERNAL OVERWEIGHT/OBESITY INDUCES PATERNAL PROGRAMMING OF OFFSPRING PHENOTYPES LIKELY MEDIATED THROUGH GENETIC AND EPIGENETIC CHANGES IN SPERMATOZOA. THESE PROGRAMMED CHANGES TO OFFSPRING HEALTH APPEAR TO BE PARTIALLY RESTORED VIA DIET/EXERCISE INTERVENTIONS IN OBESE FATHERS PRECONCEPTION, WHICH HAVE BEEN SHOWN TO IMPROVE ASPECTS OF SPERM DNA INTEGRITY. HOWEVER, THE MAJORITY OF DATA SURROUNDING PATERNAL OBESITY AND OFFSPRING PHENOTYPES HAVE COME FROM RODENT MODELS; THEREFORE, WE CONTEND THAT IT WILL BE INCREASINGLY IMPORTANT TO STUDY POPULATION-BASED DATA TO DETERMINE THE LIKELY MODE OF INHERITANCE IN HUMANS. 2014 5 2468 23 EPIGENETIC TOXICOLOGY AS TOXICANT-INDUCED CHANGES IN INTRACELLULAR SIGNALLING LEADING TO ALTERED GAP JUNCTIONAL INTERCELLULAR COMMUNICATION. COMMUNICATION MECHANISMS [EXTRA-, INTRA-, AND GAP JUNCTIONAL INTER-CELLULAR COMMUNICATION (GJIC)] CONTROL, FROM THE FERTILIZED EGG, THROUGH EMBRYOGENESIS TO MATURITY AND AGING, WHETHER A CELL PROLIFERATES, DIFFERENTIATES, DIES BY APOPTOSIS, OR IF DIFFERENTIATED, ADAPTIVELY RESPONDS TO ENDOGENOUS AND EXOGENOUS SIGNALS. FROM THE EGG TO THE 100 TRILLION CELLS IN THE HUMAN BODY, HEALTH IS MAINTAINED WHEN THESE COMMUNICATION PROCESSES BETWEEN STEM, PROGENITOR AND TERMINALLY DIFFERENTIATED CELLS ARE INTEGRATED. EACH CELL CHOICE INVOLVES 'EPIGENETIC' MECHANISMS TO ALTER THE EXPRESSION OF GENES AT THE TRANSCRIPTIONAL, TRANSLATIONAL OR POST-TRANSLATIONAL LEVELS. DISRUPTION OF THE COMMUNICATION MECHANISMS CAN BE EITHER ADAPTIVE OR MALADAPTIVE. MODULATION OF EXTRA-CELLULAR COMMUNICATION, EITHER BY GENETIC IMBALANCES OF GROWTH FACTORS, HORMONES OR NEUROTRANSMITTERS OR BY ENVIRONMENTAL, EXOGENOUS CHEMICALS CAN TRIGGER SIGNAL TRANSDUCING INTRA-CELLULAR MECHANISMS. THESE INTRA-CELLULAR SIGNALS CAN MODULATE GENE EXPRESSION AT THE TRANSCRIPTIONAL, TRANSLATIONAL OR POST-TRANSLATIONAL LEVELS WHILE ALSO MODULATING GJIC. UNTIMELY OR CHRONIC DISRUPTION OF GJIC DURING EMBRYONIC OR FETAL DEVELOPMENT COULD LEAD TO EMBRYONIC LETHALITY OR TERATOGENESIS. BY MODULATION OF GJIC, HOMEOSTATIC CONTROL OF CELL GROWTH, DIFFERENTIATION OR APOPTOSIS COULD LEAD TO SPECIFIC DISEASES, SUCH AS NEUROLOGICAL, CARDIOVASCULAR, REPRODUCTIVE OR ENDOCRINOLOGICAL DYSFUNCTION. CHEMICAL MODULATION OR ONCOGENE DOWN-REGULATION OF GJIC IN INITIATED TISSUES HAS BEEN SHOWN TO LEAD TO TUMOR PROMOTION. GENETIC SYNDROMES CARRYING A MUTATED GAP JUNCTION GENE, TOGETHER WITH SOME TRANSGENIC AND KNOCK-OUT GAP JUNCTION GENE MICE, PROVIDE EVIDENCE FOR THE IMPORTANCE OF THIS ORGANELLE FOUND ONLY IN METAZOANS. IMPLICATIONS FOR 'THRESHOLDS' TO TOXICANTS AND FOR RISK ASSESSMENT ARE EVIDENT. 1998 6 892 29 CHRONIC ETHANOL EXPOSURE ALTERS DNA METHYLATION IN NEURAL STEM CELLS: ROLE OF MOUSE STRAIN AND SEX. PRENATAL ALCOHOL EXPOSURE (PAE) IS CONSIDERED AS A RISK FACTOR FOR THE DEVELOPMENT OF FETAL ALCOHOL SPECTRUM DISORDERS (FASD). EVIDENCE INDICATES THAT PAE AFFECTS EPIGENETIC MECHANISMS (SUCH AS DNA METHYLATION) AND ALTERS THE NORMAL DIFFERENTIATION AND DEVELOPMENT OF NEURAL STEM CELLS (NSC) IN THE FETAL BRAIN. HOWEVER, PAE EFFECTS DEPEND ON SEVERAL FACTORS SUCH AS SEX AND STRAIN OF THE STUDIED SUBJECTS. HERE, WE INVESTIGATED WHETHER MURINE SEX AND STRAIN CONTRIBUTE TO THE EFFECTS OF CHRONIC ETHANOL EXPOSURE ON DNA METHYLATION MACHINERY OF DIFFERENTIATING NSC. FURTHER, THE EFFECTS OF PAE ON GLIAL LINEAGE (INCLUDING BOTH ASTROCYTES AND OLIGODENDROCYTES) IN A SEX- AND STRAIN-DEPENDENT MANNER HAVE NOT BEEN STUDIED YET. TO EXAMINE THE EFFECTS OF CHRONIC ETHANOL EXPOSURE ON GLIOGENESIS, WE EXPOSED DIFFERENTIATING NSC TO GLIO-INDUCTIVE CULTURE CONDITIONS. APPLYING A STANDARD IN VITRO MODEL SYSTEM, WE TREATED MALE AND FEMALE DIFFERENTIATING NSC (OBTAINED FROM THE FOREBRAIN OF CD1 AND C57BL/6 EMBRYOS AT EMBRYONIC DAY 14.5) WITH CHRONIC ETHANOL EXPOSURE (70 MM) FOR 8 DAYS. WE SHOW THAT ETHANOL INDUCES GLOBAL DNA HYPOMETHYLATION, WHILE ALTERING THE EXPRESSION OF DNA METHYLATION-RELATED GENES IN A SEX- AND STRAIN-SPECIFIC MANNER. THE OBSERVED CHANGE IN CELLULAR DNA METHYLATION LEVELS WAS ASSOCIATED WITH ALTERED EXPRESSION OF GLIAL MARKERS CNPASE, GFAP, AND OLIG2 IN CD1 (BUT NOT C57BL/6) CELLS. WE CONCLUDE THAT THE IMPACT OF ETHANOL EFFECT ON DNA METHYLATION IS DEPENDENT ON CELLULAR SEX AND STRAIN. ALSO, ETHANOL IMPACT ON NEURAL STEM CELL FATE COMMITMENT WAS ONLY DETECTED IN CELLS ISOLATED FROM CD1 MOUSE STRAIN, BUT NOT IN C57BL/6 CELLS. THE RESULTS OF THE CURRENT STUDY PROVIDE EVIDENCE THAT SEX AND STRAIN OF RODENTS (C57BL/6 AND CD1) DURING GESTATION ARE IMPORTANT FACTORS, WHICH AFFECT ALCOHOL EFFECTS ON NSC DIFFERENTIATION AND DNA METHYLATION. RESULTS OF THIS STUDY MAY ALSO HELP IN INTERPRETING DATA ON THE DEVELOPMENTAL TOXICITY OF MANY COMPOUNDS DURING THE GESTATIONAL PERIOD. 2020 7 5097 33 PLASTICS DERIVED ENDOCRINE-DISRUPTING COMPOUNDS AND THEIR EFFECTS ON EARLY DEVELOPMENT. DESPITE THE FACT THAT THE ESTROGENIC EFFECTS OF BISPHENOLS WERE FIRST DESCRIBED 80 YEARS AGO, RECENT DATA ABOUT ITS POTENTIAL NEGATIVE IMPACT ON BIRTH OUTCOME PARAMETERS RAISES A STRONG RATIONALE TO INVESTIGATE FURTHER. THE ADVERSE HEALTH EFFECTS OF PLASTICS RECOMMEND TO MEASURE THE IMPACTS OF ENDOCRINE-DISRUPTING COMPOUNDS (EDCS) SUCH AS BISPHENOLS (BPA, BPS, BPF), BIS(2-ETHYLHEXYL) PHTHALATE, AND DIBUTYL PHTHALATE (DBP) IN HUMAN HEALTH. EXPOSURE TO THESE COMPOUNDS IN UTERO MAY PROGRAM THE DISEASES OF THE TESTIS, PROSTATE, KIDNEY AND ABNORMALITIES IN THE IMMUNE SYSTEM, AND CAUSE TUMORS, UTERINE HEMORRHAGE DURING PREGNANCY AND POLYCYSTIC OVARY. THESE COMPOUNDS ALSO CONTROL THE PROCESSES OF EPIGENETIC TRANSGENERATIONAL INHERITANCE OF ADULT-ONSET DISEASES BY MODULATING DNA METHYLATION AND EPIMUTATIONS IN REPRODUCTIVE CELLS. THE EARLY DEVELOPMENTAL STAGE IS THE MOST SUSCEPTIBLE WINDOW FOR DEVELOPMENTAL AND GENOMIC PROGRAMMING. THE CRITICAL STAGES OF THE EVENTS FOR A NORMAL HUMAN BIRTH LIE BETWEEN THE MANY TRANSITIONS OCCURRING BETWEEN SPERMATOGENESIS, EGG FERTILIZATION AND THE FULLY FORMED FETUS. AS THE CELLS BEGIN TO GROW AND DIFFERENTIATE, THERE ARE CRITICAL BALANCES OF HORMONES, AND PROTEIN SYNTHESIS. DATA ARE EMERGING ON HOW THESE PLASTIC-DERIVED COMPOUNDS AFFECT EMBRYOGENESIS, PLACENTATION AND FETO-PLACENTAL DEVELOPMENT SINCE PREGNANT WOMEN AND UNBORN FETUSES ARE OFTEN EXPOSED TO THESE FACTORS DURING PRECONCEPTION AND THROUGHOUT GESTATION. IMPAIRED EARLY DEVELOPMENT THAT ULTIMATELY INFLUENCES FETAL OUTCOMES IS AT THE CENTER OF MANY DEVELOPMENTAL DISORDERS AND CONTRIBUTES AN INDEPENDENT RISK FACTOR FOR ADULT CHRONIC DISEASES. THIS REVIEW WILL SUMMARIZE THE CURRENT STATUS ON THE IMPACT OF EXPOSURE TO PLASTIC DERIVED EDCS ON THE GROWTH, GENE EXPRESSION, EPIGENETIC AND ANGIOGENIC ACTIVITIES OF THE EARLY FETAL DEVELOPMENT PROCESS AND THEIR POSSIBLE EFFECTS ON BIRTH OUTCOMES. 2020 8 5661 25 SEXUAL DIMORPHISM IN EPIGENOMIC RESPONSES OF STEM CELLS TO EXTREME FETAL GROWTH. EXTREME FETAL GROWTH IS ASSOCIATED WITH INCREASED SUSCEPTIBILITY TO A RANGE OF ADULT DISEASES THROUGH AN UNKNOWN MECHANISM OF CELLULAR MEMORY. WE TESTED WHETHER HERITABLE EPIGENETIC PROCESSES IN LONG-LIVED CD34(+) HAEMATOPOIETIC STEM/PROGENITOR CELLS SHOWED EVIDENCE FOR RE-PROGRAMMING ASSOCIATED WITH THE EXTREMES OF FETAL GROWTH. HERE WE SHOW THAT BOTH FETAL GROWTH RESTRICTION AND OVER-GROWTH ARE ASSOCIATED WITH GLOBAL SHIFTS TOWARDS DNA HYPERMETHYLATION, TARGETING CIS-REGULATORY ELEMENTS IN PROXIMITY TO GENES INVOLVED IN GLUCOSE HOMEOSTASIS AND STEM CELL FUNCTION. WE FIND A SEXUALLY DIMORPHIC RESPONSE; INTRAUTERINE GROWTH RESTRICTION IS ASSOCIATED WITH SUBSTANTIALLY GREATER EPIGENETIC DYSREGULATION IN MALES, WHEREAS LARGE FOR GESTATIONAL AGE GROWTH PREDOMINANTLY AFFECTS FEMALES. THE FINDINGS ARE CONSISTENT WITH EXTREME FETAL GROWTH INTERACTING WITH VARIABLE FETAL SUSCEPTIBILITY TO INFLUENCE CELLULAR AGEING AND METABOLIC CHARACTERISTICS THROUGH EPIGENETIC MECHANISMS, POTENTIALLY GENERATING BIOMARKERS THAT COULD IDENTIFY INFANTS AT HIGHER RISK FOR CHRONIC DISEASE LATER IN LIFE. 2014 9 6672 35 USE OF A MOUSE IN VITRO FERTILIZATION MODEL TO UNDERSTAND THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE HYPOTHESIS. THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE HYPOTHESIS HOLDS THAT ALTERATIONS TO HOMEOSTASIS DURING CRITICAL PERIODS OF DEVELOPMENT CAN PREDISPOSE INDIVIDUALS TO ADULT-ONSET CHRONIC DISEASES SUCH AS DIABETES AND METABOLIC SYNDROME. IT REMAINS CONTROVERSIAL WHETHER PREIMPLANTATION EMBRYO MANIPULATION, CLINICALLY USED TO TREAT PATIENTS WITH INFERTILITY, DISTURBS HOMEOSTASIS AND AFFECTS LONG-TERM GROWTH AND METABOLISM. TO ADDRESS THIS CONTROVERSY, WE HAVE ASSESSED THE EFFECTS OF IN VITRO FERTILIZATION (IVF) ON POSTNATAL PHYSIOLOGY IN MICE. WE DEMONSTRATE THAT IVF AND EMBRYO CULTURE, EVEN UNDER CONDITIONS CONSIDERED OPTIMAL FOR MOUSE EMBRYO CULTURE, ALTER POSTNATAL GROWTH TRAJECTORY, FAT ACCUMULATION, AND GLUCOSE METABOLISM IN ADULT MICE. UNBIASED METABOLIC PROFILING IN SERUM AND MICROARRAY ANALYSIS OF PANCREATIC ISLETS AND INSULIN SENSITIVE TISSUES (LIVER, SKELETAL MUSCLE, AND ADIPOSE TISSUE) REVEALED BROAD CHANGES IN METABOLIC HOMEOSTASIS, CHARACTERIZED BY SYSTEMIC OXIDATIVE STRESS AND MITOCHONDRIAL DYSFUNCTION. ADOPTING A CANDIDATE APPROACH, WE IDENTIFY THIOREDOXIN-INTERACTING PROTEIN (TXNIP), A KEY MOLECULE INVOLVED IN INTEGRATING CELLULAR NUTRITIONAL AND OXIDATIVE STATES WITH METABOLIC RESPONSE, AS A MARKER FOR PREIMPLANTATION STRESS AND DEMONSTRATE TISSUE-SPECIFIC EPIGENETIC AND TRANSCRIPTIONAL TXNIP MISREGULATION IN SELECTED ADULT TISSUES. IMPORTANTLY, DYSREGULATION OF TXNIP EXPRESSION IS ASSOCIATED WITH ENRICHMENT FOR H4 ACETYLATION AT THE TXNIP PROMOTER THAT PERSISTS FROM THE BLASTOCYST STAGE THROUGH ADULTHOOD IN ADIPOSE TISSUE. OUR DATA SUPPORT THE VULNERABILITY OF PREIMPLANTATION EMBRYOS TO ENVIRONMENTAL DISTURBANCE AND DEMONSTRATE THAT CONCEPTION BY IVF CAN REPROGRAM METABOLIC HOMEOSTASIS THROUGH METABOLIC, TRANSCRIPTIONAL, AND EPIGENETIC MECHANISMS WITH LASTING EFFECTS FOR ADULT GROWTH AND FITNESS. THIS STUDY HAS WIDE CLINICAL RELEVANCE AND UNDERSCORES THE IMPORTANCE OF CONTINUED FOLLOW-UP OF IVF-CONCEIVED OFFSPRING. 2014 10 3119 20 GESTATIONAL EXPOSURE TO PARTICULATE AIR POLLUTION EXACERBATES THE GROWTH PHENOTYPES INDUCED BY PRECONCEPTION PATERNAL ALCOHOL USE: A MULTIPLEX MODEL OF EXPOSURE. IT IS NOW CLEAR THAT PARENTAL HISTORIES OF DRUG USE, TOXICANT EXPOSURE, AND SOCIAL STRESS ALL HAVE A SIGNIFICANT INFLUENCE ON THE HEALTH AND DEVELOPMENT OF THE NEXT GENERATION. HOWEVER, THE ABILITY OF EPIGENETIC PARENTAL LIFE MEMORIES TO INTERACT WITH SUBSEQUENT GESTATIONAL EXPOSURES AND CUMULATIVELY MODIFY THE DEVELOPMENTAL TRAJECTORY OF THE OFFSPRING REMAINS AN UNEXPLORED PERSPECTIVE IN TOXICOLOGY. STUDIES FROM OUR LABORATORY HAVE IDENTIFIED MALE-SPECIFIC POSTNATAL GROWTH RESTRICTION IN A MOUSE MODEL OF CHRONIC, PRECONCEPTION PATERNAL ALCOHOL EXPOSURE. THE GOAL OF THE CURRENT STUDY WAS TO DETERMINE IF PATERNAL ALCOHOL USE, BEFORE CONCEPTION, COULD MODIFY THE SUSCEPTIBILITY OF THE OFFSPRING TO A COMPLETELY SEPARATE EXPOSURE ENCOUNTERED BY THE MOTHER DURING PREGNANCY. IN INDEPENDENT EXPERIMENTS, WE PREVIOUSLY IDENTIFIED ALTERED DEVELOPMENTAL PROGRAMMING AND INCREASED MARKERS OF SEVERE ASTHMA INDUCED BY GESTATIONAL EXPOSURE TO PARTICULATE AIR POLLUTION. IN THIS STUDY, MALE MICE WERE EXPOSED TO EITHER THE CONTROL OR ALCOHOL PRECONCEPTION TREATMENTS, THEN MATED TO NAIVE FEMALES, WHICH WE SUBSEQUENTLY EXPOSED TO AN ULTRAFINE MIXTURE OF PARTICULATE MATTER VIA INHALATION. INDIVIDUALLY, NEITHER PRECONCEPTION PATERNAL DRINKING NOR GESTATIONAL EXPOSURES TO PARTICULATE AIR POLLUTION IMPACTED THE POSTNATAL GROWTH OF FEMALE OFFSPRING. HOWEVER, WHEN BOTH EXPOSURES WERE COMBINED, FEMALES DISPLAYED A 30% REDUCTION IN WEIGHT GAIN. UNEXPECTEDLY, THIS EXPOSURE PARADIGM RESULTED IN A DRAMATIC POSTNATAL INCREASE IN LITTER LOSS DUE TO MATERNAL CANNIBALISM, WHICH PREVENTED ADDITIONAL MEASURES OF OFFSPRING HEALTH. THESE PRELIMINARY STUDIES PROVIDE EVIDENCE OF A COMPLEX INTERPLAY BETWEEN PRECONCEPTION LIFE HISTORY AND INTRAUTERINE ENVIRONMENTAL FACTORS IN THE CONTROL OF POSTNATAL GROWTH. 2020 11 5693 21 SILENCING OF MATERNAL HEPATIC GLUCOCORTICOID RECEPTOR IS ESSENTIAL FOR NORMAL FETAL DEVELOPMENT IN MICE. EXCESSIVE OR CHRONIC STRESS CAN LEAD TO A VARIETY OF DISEASES DUE TO ABERRANT ACTIVATION OF THE GLUCOCORTICOID RECEPTOR (GR), A LIGAND ACTIVATED TRANSCRIPTION FACTOR. PREGNANCY REPRESENTS A PARTICULAR WINDOW OF SENSITIVITY IN WHICH EXCESSIVE STRESS CAN HAVE ADVERSE OUTCOMES, PARTICULARLY ON THE DEVELOPING FETUS. HERE WE SHOW MATERNAL HEPATIC STRESS HORMONE RESPONSIVENESS IS DIMINISHED VIA EPIGENETIC SILENCING OF THE GLUCOCORTICOID RECEPTOR DURING PREGNANCY. PROVOCATIVELY, REINSTALLATION OF GR TO HEPATOCYTES DURING PREGNANCY BY ADENO-ASSOCIATED VIRAL TRANSDUCTION DYSREGULATES GENES INVOLVED IN PROLIFERATION, RESULTING IN IMPAIRED PREGNANCY-INDUCED HEPATOMEGALY. DISRUPTION OF THE MATERNAL HEPATIC ADAPTATION TO PREGNANCY RESULTS IN IN UTERO GROWTH RESTRICTION (IUGR). THESE DATA DEMONSTRATE PREGNANCY ANTAGONIZES THE LIVER-SPECIFIC EFFECTS OF STRESS HORMONE SIGNALING IN THE MATERNAL COMPARTMENT TO ULTIMATELY SUPPORT THE HEALTHY DEVELOPMENT OF EMBRYOS. 2019 12 4064 27 MATERNAL AND EARLY-LIFE CIRCADIAN DISRUPTION HAVE LONG-LASTING NEGATIVE CONSEQUENCES ON OFFSPRING DEVELOPMENT AND ADULT BEHAVIOR IN MICE. MODERN LIFE INVOLVES CHRONIC CIRCADIAN DISRUPTION THROUGH ARTIFICIAL LIGHT AND THESE DISRUPTIONS ARE ASSOCIATED WITH NUMEROUS MENTAL AND PHYSICAL HEALTH MALADIES. BECAUSE THE DEVELOPING NERVOUS SYSTEM IS PARTICULARLY VULNERABLE TO PERTURBATION, WE HYPOTHESIZED THAT EARLY-LIFE CIRCADIAN DISRUPTION WOULD NEGATIVELY IMPACT OFFSPRING DEVELOPMENT AND ADULT FUNCTION. PREGNANT MICE WERE SUBJECTED TO CHRONIC CIRCADIAN DISRUPTION FROM THE TIME OF UTERINE IMPLANTATION THROUGH WEANING. TO DISSOCIATE IN UTERO FROM POSTNATAL EFFECTS, A SUBSET OF LITTERS WAS CROSS-FOSTERED AT BIRTH FROM DISRUPTED DAMS TO CONTROL DAMS AND VICE VERSA. POSTNATAL CIRCADIAN DISRUPTION WAS ASSOCIATED WITH REDUCED ADULT BODY MASS, SOCIAL AVOIDANCE, AND HYPERACTIVITY. IN UTERO DISRUPTION RESULTED IN MORE PRONOUNCED SOCIAL AVOIDANCE AND HYPERACTIVITY, PHENOTYPES NOT ABROGATED BY CROSS-FOSTERING TO CONTROL MOTHERS. TO EXAMINE WHETHER CIRCADIAN DISRUPTION AFFECTS DEVELOPMENT BY ACTING AS AN EARLY LIFE STRESSOR, WE EXAMINED BIRTHWEIGHT, LITTER SIZE, MATERNAL CANNIBALISM, AND EPIGENETIC MODIFICATIONS. NONE OF THESE VARIABLES DIFFERED BETWEEN CONTROL AND DISRUPTED DAMS, OR RESEMBLED PATTERNS SEEN FOLLOWING EARLY-LIFE STRESS. OUR FINDINGS INDICATE THAT DEVELOPMENTAL CHRONIC CIRCADIAN DISRUPTION PERMANENTLY AFFECTS SOMATIC AND BEHAVIORAL DEVELOPMENT IN A STAGE-OF-LIFE-DEPENDENT MANNER, INDEPENDENT OF EARLY LIFE STRESS MECHANISMS, UNDERSCORING THE IMPORTANCE OF TEMPORAL STRUCTURE DURING DEVELOPMENT, BOTH IN UTERO AND EARLY POSTNATAL LIFE. 2017 13 4863 28 ORIGINS OF LIFETIME HEALTH AROUND THE TIME OF CONCEPTION: CAUSES AND CONSEQUENCES. PARENTAL ENVIRONMENTAL FACTORS, INCLUDING DIET, BODY COMPOSITION, METABOLISM, AND STRESS, AFFECT THE HEALTH AND CHRONIC DISEASE RISK OF PEOPLE THROUGHOUT THEIR LIVES, AS CAPTURED IN THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE CONCEPT. RESEARCH ACROSS THE EPIDEMIOLOGICAL, CLINICAL, AND BASIC SCIENCE FIELDS HAS IDENTIFIED THE PERIOD AROUND CONCEPTION AS BEING CRUCIAL FOR THE PROCESSES MEDIATING PARENTAL INFLUENCES ON THE HEALTH OF THE NEXT GENERATION. DURING THIS TIME, FROM THE MATURATION OF GAMETES THROUGH TO EARLY EMBRYONIC DEVELOPMENT, PARENTAL LIFESTYLE CAN ADVERSELY INFLUENCE LONG-TERM RISKS OF OFFSPRING CARDIOVASCULAR, METABOLIC, IMMUNE, AND NEUROLOGICAL MORBIDITIES, OFTEN TERMED DEVELOPMENTAL PROGRAMMING. WE REVIEW PERICONCEPTIONAL INDUCTION OF DISEASE RISK FROM FOUR BROAD EXPOSURES: MATERNAL OVERNUTRITION AND OBESITY; MATERNAL UNDERNUTRITION; RELATED PATERNAL FACTORS; AND THE USE OF ASSISTED REPRODUCTIVE TREATMENT. STUDIES IN BOTH HUMANS AND ANIMAL MODELS HAVE DEMONSTRATED THE UNDERLYING BIOLOGICAL MECHANISMS, INCLUDING EPIGENETIC, CELLULAR, PHYSIOLOGICAL, AND METABOLIC PROCESSES. WE ALSO PRESENT A META-ANALYSIS OF MOUSE PATERNAL AND MATERNAL PROTEIN UNDERNUTRITION THAT SUGGESTS DISTINCT PARENTAL PERICONCEPTIONAL CONTRIBUTIONS TO POSTNATAL OUTCOMES. WE PROPOSE THAT THE EVIDENCE FOR PERICONCEPTIONAL EFFECTS ON LIFETIME HEALTH IS NOW SO COMPELLING THAT IT CALLS FOR NEW GUIDANCE ON PARENTAL PREPARATION FOR PREGNANCY, BEGINNING BEFORE CONCEPTION, TO PROTECT THE HEALTH OF OFFSPRING. 2018 14 3595 23 IMPLICATIONS OF MATERNAL CONDITIONS AND PREGNANCY COURSE ON OFFSPRING'S MEDICAL PROBLEMS IN ADULT LIFE. IN THE LAST DECADE, NUMEROUS EPIDEMIOLOGICAL, CLINICAL AND EXPERIMENTAL DATA SHOW THAT PERICONCEPTIONAL, PERINATAL AND POSTNATAL ENVIRONMENT DETERMINES THE OFFSPRING'S RISK FOR LATER-LIFE CHRONIC DISEASE. FOR THIS PHENOMENON, THE TERM "FETAL" OR "PERINATAL PROGRAMMING" IS USED. IN EXPOSED OFFSPRING ALREADY IN CHILDHOOD AND EARLY ADULTHOOD, METABOLIC AND CARDIOVASCULAR CHANGES CAN BE OBSERVED, LEADING TO OBESITY, DIABETES AND HYPERTENSION. NOWADAYS, THE MODE OF CONCEPTION (E.G., IN VITRO FERTILIZATION), MATERNAL METABOLIC CONDITIONS (E.G., UNDERNUTRITION, OVERNUTRITION, DIABETES) AND COMPLICATIONS DURING PREGNANCY (E.G., PREECLAMPSIA, INTRAUTERINE GROWTH RESTRICTION) ARE SUSPECTED TO BE NEGATIVE PREDICTORS FOR OFFSPRING'S LONG-TERM HEALTH. MECHANISMS RESPONSIBLE FOR THESE EFFECTS STILL REMAIN MAINLY UNCLEAR, BUT INCLUDE EPIGENETIC, TRANSCRIPTIONAL, ENDOPLASMIC RETICULUM STRESS, AND REACTIVE OXYGEN SPECIES. THIS REVIEW PRESENTS A PIECE OF THE PUZZLE WITH REGARDS TO PERICONCEPTIONAL AND EARLY PERINATAL CONDITIONS DETERMINING LATER-LIFE RISK FOR CHRONIC ADULT DISEASE. 2016 15 4011 27 LOW PATERNAL DIETARY FOLATE ALTERS THE MOUSE SPERM EPIGENOME AND IS ASSOCIATED WITH NEGATIVE PREGNANCY OUTCOMES. EPIDEMIOLOGICAL STUDIES SUGGEST THAT A FATHER'S DIET CAN INFLUENCE OFFSPRING HEALTH. A PROPOSED MECHANISM FOR PATERNAL TRANSMISSION OF ENVIRONMENTAL INFORMATION IS VIA THE SPERM EPIGENOME. THE EPIGENOME INCLUDES HERITABLE INFORMATION SUCH AS DNA METHYLATION. WE HYPOTHESIZE THAT THE DIETARY SUPPLY OF METHYL DONORS WILL ALTER EPIGENETIC REPROGRAMMING IN SPERM. HERE WE FEED MALE MICE EITHER A FOLATE-DEFICIENT OR FOLATE-SUFFICIENT DIET THROUGHOUT LIFE. PATERNAL FOLATE DEFICIENCY IS ASSOCIATED WITH INCREASED BIRTH DEFECTS IN THE OFFSPRING, WHICH INCLUDE CRANIOFACIAL AND MUSCULOSKELETAL MALFORMATIONS. GENOME-WIDE DNA METHYLATION ANALYSIS AND THE SUBSEQUENT FUNCTIONAL ANALYSIS IDENTIFY DIFFERENTIAL METHYLATION IN SPERM OF GENES IMPLICATED IN DEVELOPMENT, CHRONIC DISEASES SUCH AS CANCER, DIABETES, AUTISM AND SCHIZOPHRENIA. WHILE >300 GENES ARE DIFFERENTIALLY EXPRESSED IN OFFSPRING PLACENTA, ONLY TWO CORRESPOND TO GENES WITH DIFFERENTIAL METHYLATION IN SPERM. THIS MODEL SUGGESTS EPIGENETIC TRANSMISSION MAY INVOLVE SPERM HISTONE H3 METHYLATION OR DNA METHYLATION AND THAT ADEQUATE PATERNAL DIETARY FOLATE IS ESSENTIAL FOR OFFSPRING HEALTH. 2013 16 5202 30 PRENATAL ORIGINS OF ADULT DISEASE. PURPOSE OF REVIEW: HUMAN EPIDEMIOLOGICAL AND ANIMAL STUDIES SHOW THAT MANY CHRONIC ADULT CONDITIONS HAVE THEIR ANTECEDENTS IN COMPROMISED FETAL AND EARLY POSTNATAL DEVELOPMENT. DEVELOPMENTAL PROGRAMMING IS DEFINED AS THE RESPONSE BY THE DEVELOPING MAMMALIAN ORGANISM TO A SPECIFIC CHALLENGE DURING A CRITICAL TIME WINDOW THAT ALTERS THE TRAJECTORY OF DEVELOPMENT WITH RESULTING PERSISTENT EFFECTS ON PHENOTYPE. MAMMALS PASS MORE BIOLOGICAL MILESTONES BEFORE BIRTH THAN ANY OTHER TIME IN THEIR LIVES. EACH INDIVIDUAL'S PHENOTYPE IS INFLUENCED BY THE DEVELOPMENTAL ENVIRONMENT AS MUCH AS THEIR GENES. A BETTER UNDERSTANDING IS REQUIRED OF GENE-ENVIRONMENT INTERACTIONS LEADING TO ADULT DISEASE. RECENT FINDINGS: DURING DEVELOPMENT, THERE ARE CRITICAL PERIODS OF VULNERABILITY TO SUBOPTIMAL CONDITIONS WHEN PROGRAMMING MAY PERMANENTLY MODIFY DISEASE SUSCEPTIBILITY. PROGRAMMING INVOLVES STRUCTURAL CHANGES IN IMPORTANT ORGANS; ALTERED CELL NUMBER, IMBALANCE IN DISTRIBUTION OF DIFFERENT CELL TYPES WITHIN THE ORGAN, AND ALTERED BLOOD SUPPLY OR RECEPTOR NUMBERS. COMPENSATORY EFFORTS BY THE FETUS MAY CARRY A PRICE. EFFECTS OF PROGRAMMING MAY PASS ACROSS GENERATIONS BY MECHANISMS THAT DO NOT NECESSARILY INVOLVE STRUCTURAL GENE CHANGES. PROGRAMMING OFTEN HAS DIFFERENT EFFECTS IN MALES AND FEMALES. SUMMARY: DEVELOPMENTAL PROGRAMMING SHOWS THAT EPIGENETIC FACTORS PLAY MAJOR ROLES IN DEVELOPMENT OF PHENOTYPE AND PREDISPOSITION TO DISEASE IN LATER LIFE. 2008 17 4932 20 PATERNAL ALCOHOL EXPOSURES PROGRAM INTERGENERATIONAL HORMETIC EFFECTS ON OFFSPRING FETOPLACENTAL GROWTH. HORMESIS REFERS TO GRADED ADAPTIVE RESPONSES TO HARMFUL ENVIRONMENTAL STIMULI WHERE LOW-LEVEL TOXICANT EXPOSURES STIMULATE TISSUE GROWTH AND RESPONSIVENESS WHILE, IN CONTRAST, HIGHER-LEVEL EXPOSURES INDUCE TOXICITY. ALTHOUGH THE INTERGENERATIONAL INHERITANCE OF PROGRAMMED HORMETIC GROWTH RESPONSES IS DESCRIBED IN PLANTS AND INSECTS, RESEARCHERS HAVE YET TO OBSERVE THIS PHENOMENON IN MAMMALS. USING A PHYSIOLOGICALLY RELEVANT MOUSE MODEL, WE DEMONSTRATE THAT CHRONIC PRECONCEPTION PATERNAL ALCOHOL EXPOSURES PROGRAM NONLINEAR, DOSE-DEPENDENT CHANGES IN OFFSPRING FETOPLACENTAL GROWTH. OUR STUDIES IDENTIFY AN INVERSE J-SHAPED CURVE WITH A THRESHOLD OF 2.4 G/KG PER DAY; BELOW THIS THRESHOLD, PATERNAL ETHANOL EXPOSURES INDUCE PROGRAMMED INCREASES IN PLACENTAL GROWTH, WHILE DOSES EXCEEDING THIS POINT YIELD COMPARATIVE DECREASES IN PLACENTAL GROWTH. IN MALE OFFSPRING, HIGHER PATERNAL EXPOSURES INDUCE DOSE-DEPENDENT INCREASES IN THE PLACENTAL LABYRINTH LAYER BUT DO NOT IMPACT FETAL GROWTH. IN CONTRAST, THE PLACENTAL HYPERTROPHY INDUCED BY LOW-LEVEL PATERNAL ETHANOL EXPOSURES ASSOCIATE WITH INCREASED OFFSPRING CROWN-RUMP LENGTH, PARTICULARLY IN MALE OFFSPRING. FINALLY, ALTERATIONS IN PLACENTAL PHYSIOLOGY CORRELATE WITH DISRUPTIONS IN BOTH MITOCHONDRIAL-ENCODED AND IMPRINTED GENE EXPRESSION. UNDERSTANDING THE INFLUENCE OF ETHANOL ON THE PATERNALLY-INHERITED EPIGENETIC PROGRAM AND DOWNSTREAM HORMETIC RESPONSES IN OFFSPRING GROWTH MAY HELP EXPLAIN THE ENORMOUS VARIATION OBSERVED IN FETAL ALCOHOL SPECTRUM DISORDER (FASD) PHENOTYPES AND INCIDENCE. 2022 18 5197 26 PRENATAL GLUCOCORTICOIDS EXPOSURE AND FETAL ADRENAL DEVELOPMENTAL PROGRAMMING. CLINICALLY, WE APPLY SYNTHETIC GLUCOCORTICOIDS TO TREAT FETAL AND MATERNAL DISEASES, SUCH AS PREMATURE LABOR AND AUTOIMMUNE DISEASES. ALTHOUGH ITS CLINICAL EFFICACY IS POSITIVE, THE FETUS WILL BE EXPOSED TO EXOGENOUS SYNTHETIC GLUCOCORTICOIDS. PRENATAL ADVERSE ENVIRONMENTS (SUCH AS XENOBIOTICS EXPOSURE, MALNUTRITION, INFECTION, HYPOXIA AND STRESS) CAN CAUSE FETUSES OVEREXPOSURE TO EXCESSIVE ENDOGENOUS MATERNAL GLUCOCORTICOIDS. THE LEVEL OF GLUCOCORTICOIDS IS THE KEY TO FETAL TISSUE MATURATION AND POSTNATAL FATE. A LARGE NUMBER OF STUDIES HAVE FOUND THAT PRENATAL GLUCOCORTICOIDS EXPOSURE CAN LEAD TO FETAL ADRENAL DYSPLASIA AND DYSFUNCTION, CONTINUING AFTER BIRTH AND EVEN INTO ADULTHOOD. AS THE CORE ORGAN OF FETAL-ORIGINATED ADULT DISEASES, FETAL ADRENAL DYSPLASIA IS CLOSELY RELATED TO THE SUSCEPTIBILITY AND OCCURRENCE OF MULTIPLE CHRONIC DISEASES, AND THERE ARE ALSO OBVIOUS GENDER DIFFERENCES. HOWEVER, ITS INTRAUTERINE PROGRAMMING MECHANISMS HAVE NOT BEEN FULLY ELUCIDATED. THIS REVIEW SUMMARIZES RECENT ADVANCES IN PRENATAL GLUCOCORTICOIDS EXPOSURE AND FETAL ADRENAL DEVELOPMENTAL PROGRAMMING ALTERATIONS, WHICH IS OF GREAT SIGNIFICANCE FOR EXPLAINING ADRENAL DEVELOPMENTAL TOXICITY AND THE INTRAUTERINE ORIGIN OF FETAL-ORIGINATED ADULT DISEASES. 2019 19 4790 33 NUTRITIONAL ADVERSITY, SEX AND REPRODUCTION: 30 YEARS OF DOHAD AND WHAT HAVE WE LEARNED? IT IS WELL ESTABLISHED THAT EARLY LIFE ENVIRONMENTAL SIGNALS, INCLUDING NUTRITION, SET THE STAGE FOR LONG-TERM HEALTH AND DISEASE RISK - EFFECTS THAT SPAN MULTIPLE GENERATIONS. THIS RELATIONSHIP BEGINS EARLY, IN THE PERICONCEPTIONAL PERIOD AND EXTENDS INTO EMBRYONIC, FETAL AND EARLY INFANT PHASES OF LIFE. NOW KNOWN AS THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE (DOHAD), THIS CONCEPT DESCRIBES THE ADAPTATIONS THAT A DEVELOPING ORGANISM MAKES IN RESPONSE TO EARLY LIFE CUES, RESULTING IN ADJUSTMENTS IN HOMEOSTATIC SYSTEMS THAT MAY PROVE MALADAPTIVE IN POSTNATAL LIFE, LEADING TO AN INCREASED RISK OF CHRONIC DISEASE AND/OR THE INHERITANCE OF RISK FACTORS ACROSS GENERATIONS. REPRODUCTIVE MATURATION AND FUNCTION IS SIMILARLY INFLUENCED BY EARLY LIFE EVENTS. THIS SHOULD NOT BE SURPRISING, SINCE PRIMORDIAL GERM CELLS ARE ESTABLISHED EARLY IN LIFE AND THUS VULNERABLE TO EARLY LIFE ADVERSITY. A MULTITUDE OF 'MODIFYING' CUES INDUCING DEVELOPMENTAL ADAPTATIONS HAVE BEEN IDENTIFIED THAT RESULT IN CHANGES IN REPRODUCTIVE DEVELOPMENT AND IMPAIRMENTS IN REPRODUCTIVE FUNCTION. MANY TYPES OF NUTRITIONAL CHALLENGES INCLUDING CALORIC RESTRICTION, MACRONUTRIENT EXCESS AND MICRONUTRIENT INSUFFICIENCIES HAVE BEEN SHOWN TO INDUCE EARLY LIFE ADAPTATIONS THAT PRODUCE LONG-TERM REPRODUCTIVE DYSFUNCTION. MANY PATHWAYS HAVE BEEN SUGGESTED TO UNDERPIN THESE ASSOCIATIONS, INCLUDING EPIGENETIC REPROGRAMMING OF GERM CELLS. WHILE THE MECHANISMS STILL REMAIN TO BE FULLY INVESTIGATED, IT IS CLEAR THAT A LIFECOURSE APPROACH TO UNDERSTANDING LIFETIME REPRODUCTIVE FUNCTION IS NECESSARY. FURTHERMORE, INVESTIGATIONS OF THE IMPACTS OF EARLY LIFE ADVERSITY MUST BE EXTENDED TO INCLUDE THE PATERNAL ENVIRONMENT, ESPECIALLY IN EPIDEMIOLOGICAL AND CLINICAL STUDIES OF OFFSPRING REPRODUCTIVE FUNCTION. 2019 20 2183 21 EPIGENETIC MECHANISMS RESPONSIBLE FOR THE TRANSGENERATIONAL INHERITANCE OF INTRAUTERINE GROWTH RESTRICTION PHENOTYPES. A POORLY FUNCTIONING PLACENTA RESULTS IN IMPAIRED EXCHANGES OF OXYGEN, NUTRITION, WASTES AND HORMONES BETWEEN THE MOTHER AND HER FETUS. THIS CAN LEAD TO RESTRICTION OF FETAL GROWTH. THESE GROWTH RESTRICTED BABIES ARE AT INCREASED RISK OF DEVELOPING CHRONIC DISEASES, SUCH AS TYPE-2 DIABETES, HYPERTENSION, AND KIDNEY DISEASE, LATER IN LIFE. ANIMAL STUDIES HAVE SHOWN THAT GROWTH RESTRICTED PHENOTYPES ARE SEX-DEPENDENT AND CAN BE TRANSMITTED TO SUBSEQUENT GENERATIONS THROUGH BOTH THE PATERNAL AND MATERNAL LINEAGES. ALTERED EPIGENETIC MECHANISMS, SPECIFICALLY CHANGES IN DNA METHYLATION, HISTONE MODIFICATIONS, AND NON-CODING RNAS THAT REGULATE EXPRESSION OF GENES THAT ARE IMPORTANT FOR FETAL DEVELOPMENT HAVE BEEN SHOWN TO BE ASSOCIATED WITH THE TRANSMISSION PATTERN OF GROWTH RESTRICTED PHENOTYPES. THIS REVIEW WILL DISCUSS THE SUBSEQUENT HEALTH OUTCOMES IN THE OFFSPRING AFTER GROWTH RESTRICTION AND THE TRANSMISSION PATTERNS OF THESE DISEASES. EVIDENCE OF ALTERED EPIGENETIC MECHANISMS IN ASSOCIATION WITH FETAL GROWTH RESTRICTION WILL ALSO BE REVIEWED. 2022