1 3301 87 HIGH-FAT OR ETHINYL-OESTRADIOL INTAKE DURING PREGNANCY INCREASES MAMMARY CANCER RISK IN SEVERAL GENERATIONS OF OFFSPRING. MATERNAL EXPOSURES TO ENVIRONMENTAL FACTORS DURING PREGNANCY INFLUENCE THE RISK OF MANY CHRONIC ADULT-ONSET DISEASES IN THE OFFSPRING. HERE WE INVESTIGATE WHETHER FEEDING PREGNANT RATS A HIGH-FAT (HF)- OR ETHINYL-OESTRADIOL (EE2)-SUPPLEMENTED DIET AFFECTS CARCINOGEN-INDUCED MAMMARY CANCER RISK IN DAUGHTERS, GRANDDAUGHTERS AND GREAT-GRANDDAUGHTERS. WE SHOW THAT MAMMARY TUMOURIGENESIS IS HIGHER IN DAUGHTERS AND GRANDDAUGHTERS OF HF RAT DAMS AND IN DAUGHTERS AND GREAT-GRANDDAUGHTERS OF EE2 RAT DAMS. OUTCROSS EXPERIMENTS SUGGEST THAT THE INCREASE IN MAMMARY CANCER RISK IS TRANSMITTED TO HF GRANDDAUGHTERS EQUALLY THROUGH THE FEMALE OR MALE GERM LINES, BUT IT IS ONLY TRANSMITTED TO EE2 GRANDDAUGHTERS THROUGH THE FEMALE GERM LINE. THE EFFECTS OF MATERNAL EE2 EXPOSURE ON OFFSPRING'S MAMMARY CANCER RISK ARE ASSOCIATED WITH CHANGES IN THE DNA METHYLATION MACHINERY AND METHYLATION PATTERNS IN MAMMARY TISSUE OF ALL THREE EE2 GENERATIONS. WE CONCLUDE THAT DIETARY AND OESTROGENIC EXPOSURES IN PREGNANCY INCREASE BREAST CANCER RISK IN MULTIPLE GENERATIONS OF OFFSPRING, POSSIBLY THROUGH EPIGENETIC MEANS. 2012 2 184 28 ACCOUNTING FOR TRANSGENERATIONAL EFFECTS OF TOXICANT EXPOSURE IN POPULATION MODELS ALTERS THE PREDICTED LONG-TERM POPULATION STATUS. ACUTE ENVIRONMENTAL STRESSORS SUCH AS SHORT-TERM EXPOSURE TO POLLUTANTS CAN HAVE LASTING EFFECTS ON ORGANISMS, POTENTIALLY IMPACTING FUTURE GENERATIONS. PARENTAL EXPOSURE TO TOXICANTS CAN RESULT IN CHANGES TO THE EPIGENOME (E.G., DNA METHYLATION) THAT ARE PASSED DOWN TO SUBSEQUENT, UNEXPOSED GENERATIONS. HOWEVER, IT IS DIFFICULT TO GAUGE THE CUMULATIVE POPULATION-SCALE IMPACTS OF EPIGENETIC EFFECTS FROM LABORATORY EXPERIMENTS ALONE. HERE, WE DEVELOPED A SIZE- AND AGE-STRUCTURED DELAY-COORDINATE POPULATION MODEL TO EVALUATE THE LONG-TERM CONSEQUENCES OF EPIGENETIC MODIFICATIONS ON POPULATION SUSTAINABILITY. THE MODEL EMULATED CHANGES IN GROWTH, MORTALITY, AND FECUNDITY IN THE F0, F1, AND F2 GENERATIONS OBSERVED IN EXPERIMENTS IN WHICH LARVAL MENIDIA BERYLLINA WERE EXPOSED TO ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF BIFENTHRIN (BIF), ETHINYLESTRADIOL (EE2), LEVONORGESTREL (LV), OR TRENBOLONE (TB) IN THE PARENT GENERATION (F0) AND REARED IN CLEAN WATER UP TO THE F2 GENERATION. OUR ANALYSIS SUGGESTS POTENTIALLY DRAMATIC POPULATION-LEVEL EFFECTS OF REPEATED, CHRONIC EXPOSURES OF EARLY-LIFE STAGE FISH THAT ARE NOT CAPTURED BY MODELS NOT ACCOUNTING FOR THOSE EFFECTS. SIMULATED EXPOSURES LED TO SUBSTANTIAL DECLINES IN POPULATION ABUNDANCE (LV AND BIF) OR NEAR-EXTINCTION (EE2 AND TB) WITH THE EXACT TRAJECTORY AND TIMELINE OF POPULATION DECLINE DEPENDENT ON THE COMBINATION OF F0, F1, AND F2 EFFECTS PRODUCED BY EACH COMPOUND. EVEN ACUTE ONE-TIME EXPOSURES OF EACH COMPOUND LED TO DECLINES AND RECOVERY OVER MULTIPLE YEARS DUE TO LAGGED EPIGENETIC EFFECTS. THESE RESULTS DEMONSTRATE THE POTENTIAL FOR ENVIRONMENTALLY RELEVANT CONCENTRATIONS OF COMMONLY USED COMPOUNDS TO IMPACT THE POPULATION DYNAMICS AND SUSTAINABILITY OF AN ECOLOGICALLY RELEVANT SPECIES AND MODEL ORGANISM. 2022 3 6594 27 TUMOR-AUGMENTING EFFECTS OF GESTATIONAL ARSENIC EXPOSURE ON F1 AND F2 IN MICE. THE CONSEQUENCES OF EARLY-LIFE EXPOSURE TO CHEMICALS IN THE ENVIRONMENT ARE EMERGING CONCERNS. CHRONIC EXPOSURE TO NATURALLY OCCURRING INORGANIC ARSENIC HAS BEEN KNOWN TO CAUSE VARIOUS ADVERSE HEALTH EFFECTS, INCLUDING CANCERS, IN HUMANS. ON THE OTHER HAND, ANIMAL STUDIES BY DR. M. WAALKES' GROUP REPORTED THAT ARSENITE EXPOSURE OF PREGNANT F0 FEMALES, ONLY FROM GESTATIONAL DAY 8 TO 18, INCREASED HEPATIC TUMORS IN THE F1 (ARSENITE-F1) MALES OF C3H MICE, WHOSE MALES TEND TO DEVELOP SPONTANEOUS HEPATIC TUMORS LATER IN LIFE. SINCE THIS MICE MODEL ILLUMINATED NOVEL UNIDENTIFIED CONSEQUENCES OF ARSENIC EXPOSURE, WE WISHED TO FURTHER INVESTIGATE THE BACKGROUND MECHANISMS. IN THE SAME EXPERIMENTAL MODEL, WE IDENTIFIED A VARIETY OF FACTORS THAT WERE AFFECTED BY GESTATIONAL ARSENIC EXPOSURE, INCLUDING EPIGENETIC AND GENETIC CHANGES, AS POSSIBLE CONSTITUENTS OF MULTIPLE STEPS OF LATE-ONSET HEPATIC TUMOR AUGMENTATION IN ARSENITE-F1 MALES. FURTHERMORE, OUR STUDY DISCOVERED THAT THE F2 MALES BORN TO ARSENITE-F1 MALES DEVELOPED HEPATIC TUMORS AT A SIGNIFICANTLY HIGHER RATE THAN THE CONTROL F2 MALES. THE RESULTS IMPLY THAT THE TUMOR AUGMENTING EFFECT IS INHERITED BY ARSENITE-F2 MALES THROUGH THE SPERM OF ARSENITE-F1. IN THIS ARTICLE, WE SUMMARIZED OUR STUDIES ON THE CONSEQUENCES OF GESTATIONAL ARSENITE EXPOSURE IN F1 AND F2 MICE TO DISCUSS NOVEL ASPECTS OF BIOLOGICAL EFFECTS OF GESTATIONAL ARSENIC EXPOSURE. 2017 4 6008 29 THE ANTI-INFLAMMATORY AGENT 5-ASA REDUCES THE LEVEL OF SPECIFIC TSRNAS IN SPERM CELLS OF HIGH-FAT FED C57BL/6J MOUSE SIRES AND IMPROVES GLUCOSE TOLERANCE IN FEMALE OFFSPRING. INTRODUCTION: THE PREVALENCE OF OBESITY AND ASSOCIATED COMORBIDITIES HAVE INCREASED TO EPIDEMIC PROPORTIONS GLOBALLY. PATERNAL OBESITY IS AN INDEPENDENT RISK FACTOR FOR DEVELOPING OBESITY AND TYPE 2 DIABETES IN THE FOLLOWING GENERATION, AND GROWING EVIDENCE SUGGESTS EPIGENETIC INHERITANCE AS A MECHANISM FOR THIS PREDISPOSITION. HOW AND WHY OBESITY INDUCES EPIGENETIC CHANGES IN SPERM CELLS REMAIN TO BE CLARIFIED IN DETAIL. YET, RECENT STUDIES SHOW THAT ALTERATIONS IN SPERM CONTENT OF TRANSFER RNA-DERIVED SMALL RNAS (TSRNAS) CAN TRANSMIT THE EFFECTS OF PATERNAL OBESITY TO OFFSPRING. OBESITY IS CLOSELY ASSOCIATED WITH LOW-GRADE CHRONIC INFLAMMATION. THUS, WE EVALUATED WHETHER THE ANTI-INFLAMMATORY AGENT 5-AMINOSALICYLIC ACID (5-ASA) COULD INTERVENE IN THE TRANSMISSION OF EPIGENETIC INHERITANCE OF PATERNAL OBESITY BY REDUCING THE INFLAMMATORY STATE IN OBESE FATHERS. METHODS: MALE C57BL/6JBOMTAC MICE WERE EITHER FED A HIGH-FAT DIET OR A HIGH-FAT DIET WITH 5-ASA FOR TEN WEEKS BEFORE MATING. THE OFFSPRING METABOLIC PHENOTYPE WAS EVALUATED, AND SPERMATOZOA FROM SIRES WERE ISOLATED FOR ASSESSMENT OF SPECIFIC TSRNAS LEVELS. RESULTS: 5-ASA INTERVENTION REDUCED THE LEVELS OF GLU-CTC TSRNAS IN SPERM CELLS AND IMPROVED GLUCOSE TOLERANCE IN FEMALE OFFSPRING FED A CHOW DIET. PATERNAL HIGH-FAT DIET-INDUCED OBESITY PER SE HAD ONLY A MODERATE IMPACT ON THE METABOLIC PHENOTYPE OF BOTH MALE AND FEMALE OFFSPRING IN OUR SETTING. CONCLUSION: THE RESULTS INDICATE THAT THE LOW-GRADE INFLAMMATORY RESPONSE ASSOCIATED WITH OBESITY MAY BE AN IMPORTANT FACTOR IN EPIGENETIC INHERITANCE OF PATERNAL OBESITY. 2023 5 4089 31 MATERNAL OBESITY PROGRAMS SENESCENCE SIGNALING AND GLUCOSE METABOLISM IN OSTEO-PROGENITORS FROM RAT AND HUMAN. NUTRITIONAL STATUS DURING INTRAUTERINE AND EARLY POSTNATAL LIFE IMPACTS THE RISK OF CHRONIC DISEASES, PRESUMABLY VIA EPIGENETIC MECHANISMS. HOWEVER, EVIDENCE ON THE IMPACT OF GESTATIONAL EVENTS ON REGULATION OF EMBRYONIC BONE CELL FATE IS SPARSE. WE INVESTIGATED THE EFFECTS OF MATERNAL OBESITY ON FETAL OSTEOBLAST DEVELOPMENT IN BOTH RODENTS AND HUMANS. FEMALE RATS WERE FED CONTROL OR AN OBESOGENIC HIGH-FAT DIET (HFD) FOR 12 WEEKS AND MATED WITH MALE RATS FED CONTROL DIETS, AND RESPECTIVE MATERNAL DIETS WERE CONTINUED DURING PREGNANCY. EMBRYONIC RAT OSTEOGENIC CALVARIAL CELLS (EOCCS) WERE TAKEN FROM GESTATIONAL DAY 18.5 FETUSES FROM CONTROL AND HFD DAMS. EOCCS FROM HFD OBESE DAMS SHOWED INCREASES IN P53/P21-MEDIATED CELL SENESCENCE SIGNALING BUT DECREASED GLUCOSE METABOLISM. DECREASED AEROBIC GLYCOLYSIS IN HFD-EOCCS WAS ASSOCIATED WITH DECREASED OSTEOBLASTIC CELL DIFFERENTIATION AND PROLIFERATION. UMBILICAL CORD HUMAN MESENCHYMAL STEM CELLS (MSCS) FROM 24 PREGNANT WOMEN (12 OBESE AND 12 LEAN) ALONG WITH PLACENTAS WERE COLLECTED UPON DELIVERY. THE UMBILICAL CORD MSCS OF OBESE MOTHERS DISPLAYED LESS POTENTIAL TOWARD OSTEOBLASTOGENESIS AND MORE TOWARDS ADIPOGENESIS. HUMAN MSCS AND PLACENTA FROM OBESE MOTHERS ALSO EXHIBITED INCREASED CELL SENESCENCE SIGNALING, WHEREAS MSCS SHOWED DECREASED GLUCOSE METABOLISM AND INSULIN RESISTANCE. FINALLY, WE SHOWED THAT OVEREXPRESSION OF P53 LINKED INCREASED CELL SENESCENCE SIGNALING AND DECREASED GLUCOSE METABOLISM IN FETAL OSTEO-PROGENITORS FROM OBESE RATS AND HUMANS. THESE FINDINGS SUGGEST PROGRAMMING OF FETAL PREOSTEOBLASTIC CELL SENESCENCE SIGNALING AND GLUCOSE METABOLISM BY MATERNAL OBESITY. 2016 6 3238 32 HEPATIC EPIGENETIC REPROGRAMMING AFTER LIVER RESECTION IN OFFSPRING ALLEVIATES THE EFFECTS OF MATERNAL OBESITY. OBESITY HAS BECOME A PUBLIC HEALTH PROBLEM IN RECENT DECADES, AND DURING PREGNANCY, IT CAN LEAD TO AN INCREASED RISK OF GESTATIONAL COMPLICATIONS AND PERMANENT CHANGES IN THE OFFSPRING RESULTING FROM A PROCESS KNOWN AS METABOLIC PROGRAMMING. THE OFFSPRING OF OBESE DAMS ARE AT INCREASED RISK OF DEVELOPING NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD), EVEN IN THE ABSENCE OF HIGH-FAT DIET CONSUMPTION. NAFLD IS A CHRONIC FATTY LIVER DISEASE THAT CAN PROGRESS TO EXTREMELY SEVERE CONDITIONS THAT REQUIRE SURGICAL INTERVENTION WITH THE REMOVAL OF THE INJURED TISSUE. LIVER REGENERATION IS NECESSARY TO PRESERVE ORGAN FUNCTION. A RANGE OF PATHWAYS IS ACTIVATED IN THE LIVER REGENERATION PROCESS, INCLUDING THE HIPPO, TGFBETA, AND AMPK SIGNALING PATHWAYS THAT ARE UNDER EPIGENETIC CONTROL. WE INVESTIGATED WHETHER MICRORNA MODULATION IN THE LIVER OF THE OFFSPRING OF OBESE DAMS WOULD IMPACT GENE EXPRESSION OF HIPPO, TGFBETA, AND AMPK PATHWAYS AND TISSUE REGENERATION AFTER PARTIAL HEPATECTOMY (PHX). FEMALE SWISS MICE FED A STANDARD CHOW OR A HIGH-FAT DIET (HFD) BEFORE AND DURING PREGNANCY AND LACTATION WERE MATED WITH MALE CONTROL MICE. THE OFFSPRING FROM CONTROL (CT-O) AND OBESE (HF-O) DAMS WEANED TO STANDARD CHOW DIET UNTIL DAY 56 WERE SUBMITTED TO PHX SURGERY. PRIOR TO THE SURGERY, HF-O PRESENTED ALTERATIONS IN MIR-122, MIR-370, AND LET-7A EXPRESSION IN THE LIVER COMPARED TO CT-O, AS PREVIOUSLY SHOWN, AS WELL AS IN ITS TARGET GENES INVOLVED IN LIVER REGENERATION. HOWEVER, AFTER THE PHX (4 H OR 48 H POST-SURGERY), DIFFERENCES IN GENE EXPRESSION BETWEEN CT-O AND HF-O WERE SUPPRESSED, AS WELL AS IN MICRORNA EXPRESSION IN THE LIVER. FURTHERMORE, BOTH CT-O AND HF-O PRESENTED A SIMILAR REGENERATIVE CAPACITY OF THE LIVER WITHIN 48 H AFTER PHX. OUR RESULTS SUGGEST THAT SURVIVAL AND REGENERATIVE MECHANISMS INDUCED BY THE PARTIAL HEPATECTOMY MAY OVERCOME THE EPIGENETIC CHANGES IN THE LIVER OF OFFSPRING PROGRAMMED BY MATERNAL OBESITY. 2022 7 4736 26 NOVEL EPIGENETIC BIOMARKERS MEDIATING BISPHENOL A EXPOSURE AND METABOLIC PHENOTYPES IN FEMALE MICE. THERE IS COMPELLING EVIDENCE THAT EPIGENETIC MODIFICATIONS LINK DEVELOPMENTAL ENVIRONMENTAL INSULTS TO ADULT DISEASE SUSCEPTIBILITY. ANIMAL STUDIES HAVE ASSOCIATED PERINATAL BISPHENOL A (BPA) EXPOSURE TO ALTERED DNA METHYLATION, BUT THESE STUDIES ARE OFTEN LIMITED TO CANDIDATE GENE AND GLOBAL NON-LOCI-SPECIFIC APPROACHES. BY USING AN EPIGENOME-WIDE DISCOVERY PLATFORM, WE ELUCIDATED EPIGENETIC ALTERATIONS IN LIVER TISSUE FROM ADULT MICE OFFSPRING (10 MONTHS) FOLLOWING PERINATAL BPA EXPOSURE AT HUMAN PHYSIOLOGICALLY RELEVANT DOSES (50-NG, 50-MUG, AND 50-MG BPA/KG DIET). BIOLOGICAL PATHWAY ANALYSIS IDENTIFIED AN ENRICHMENT OF SIGNIFICANT DIFFERENTIALLY METHYLATED REGIONS IN METABOLIC PATHWAYS AMONG FEMALES. FURTHERMORE, THROUGH THE USE OF TOP ENRICHED BIOLOGICAL PATHWAYS, 4 CANDIDATE GENES WERE CHOSEN TO ASSESS DNA METHYLATION AS A MEDIATING FACTOR LINKING THE ASSOCIATION OF PERINATAL BPA EXPOSURE TO METABOLIC PHENOTYPES PREVIOUSLY OBSERVED IN FEMALE OFFSPRING. DNA METHYLATION STATUS AT JANUS KINASE-2 (JAK-2), RETINOID X RECEPTOR (RXR), REGULATORY FACTOR X-ASSOCIATED PROTEIN (RFXAP), AND TRANSMEMBRANE PROTEIN 238 (TMEM238) WAS USED WITHIN A MEDIATIONAL REGRESSION ANALYSIS. DNA METHYLATION IN ALL FOUR OF THE CANDIDATE GENES WAS IDENTIFIED AS A MEDIATOR IN THE MECHANISTIC PATHWAY OF DEVELOPMENTAL BPA EXPOSURE AND FEMALE-SPECIFIC ENERGY EXPENDITURE, BODY WEIGHT, AND BODY FAT PHENOTYPES. DATA GENERATED FROM THIS STUDY ARE CRUCIAL FOR DECIPHERING THE MECHANISTIC ROLE OF EPIGENETICS IN THE PATHOGENESIS OF CHRONIC DISEASE AND THE DEVELOPMENT OF EPIGENETIC-BASED PREVENTION AND THERAPEUTIC STRATEGIES FOR COMPLEX HUMAN DISEASE. 2017 8 1368 35 DEVELOPMENTAL ORIGINS OF DISEASE AND DETERMINANTS OF CHROMATIN STRUCTURE: MATERNAL DIET MODIFIES THE PRIMATE FETAL EPIGENOME. CHROMATIN STRUCTURE IS EPIGENETICALLY ALTERED VIA COVALENT MODIFICATIONS OF HISTONES TO ALLOW FOR HERITABLE GENE REGULATION WITHOUT ALTERING THE NUCLEOTIDE SEQUENCE. MULTIPLE LINES OF EVIDENCE FROM RODENTS HAVE ESTABLISHED A ROLE FOR EPIGENETIC REMODELING IN REGULATING GENE TRANSCRIPTION IN RESPONSE TO AN ALTERED GESTATIONAL MILIEU. HOWEVER, TO DATE, IT IS UNKNOWN WHETHER VARIATIONS IN THE INTRAUTERINE ENVIRONMENT IN PRIMATES SIMILARLY INDUCE CHANGES IN KEY DETERMINANTS OF HEPATIC CHROMATIN STRUCTURE. WE HYPOTHESIZED THAT A MATERNAL HIGH-FAT DIET WOULD ALTER THE EPIGENOMIC PROFILE OF THE DEVELOPING OFFSPRING, WHICH WOULD RESULT IN ALTERATIONS IN FETAL GENE EXPRESSION. AGE- AND WEIGHT-MATCHED ADULT FEMALE JAPANESE MACAQUES WERE PLACED ON CONTROL (13% FAT) OR HIGH-FAT (35% FAT) BREEDER DIETS AND MATED ANNUALLY OVER A 4-YEAR INTERVAL. FETUSES IN SUCCESSIVE YEARS WERE DELIVERED NEAR TERM (E130 OF 167 DAYS) AND UNDERWENT NECROPSY WITH TISSUE HARVEST. FETAL HISTONES WERE ACID EXTRACTED FOR CHARACTERIZATION OF H3 MODIFICATION AND CHROMATIN IMMUNOPRECIPITATION (CHIP) WITH DIFFERENTIAL DISPLAY PCR; FETAL RNA, DNA, AND CYTOPLASMIC AND NUCLEAR PROTEIN EXTRACTS WERE SIMILARLY EXTRACTED FOR COMPARISON. CHRONIC CONSUMPTION OF A MATERNAL HIGH-FAT DIET RESULTS IN A THREEFOLD INCREASE IN FETAL LIVER TRIGLYCERIDES AND HISTOLOGIC CORRELATES OF NON-ALCOHOLIC FATTY LIVER DISEASE. THESE GROSS CHANGES IN THE FETAL LIVER ARE ACCOMPANIED BY A STATISTICALLY SIGNIFICANT HYPERACETYLATION OF FETAL HEPATIC TISSUE AT H3K14 (199.85+/-9.64 VS 88.8+/-45.4; P=0.038) WITH A TREND TOWARDS THE INCREASED ACETYLATION AT H3K9 (140.9+/-38.7 VS 46.6+/-6.53; P=0.097) AND AT H3K18 (69.0+/-3.54 VS 58.0+/-4.04; P=0.096). HOWEVER, EPIGENETIC MODIFICATIONS ON FETAL HEPATIC H3 ASSOCIATED WITH GENE REPRESSION WERE ABSENT OR SUBTLE (P>0.05). SUBSEQUENT CHARACTERIZATION OF KEY EPIGENETIC DETERMINANTS ASSOCIATED WITH H3 ACETYLATION MARKS REVEALED SIMILAR SIGNIFICANT ALTERATIONS IN ASSOCIATION WITH A HIGH-FAT MATERNAL DIET (E.G., RELATIVE FETAL HISTONE DEACETYLASE 1 (HDAC1) GENE EXPRESSION 0.61+/-0.25; P=0.011). CONSISTENT WITH OUR MRNA EXPRESSION PROFILE, FETAL NUCLEAR EXTRACTS FROM OFFSPRING OF HIGH-FAT DIET ANIMALS WERE OBSERVED TO BE SIGNIFICANTLY RELATIVELY DEPLETE OF HDAC1 PROTEIN (36.07+/-6.73 VS 83.18+/-7.51; P=0.006) AND IN VITRO HDAC FUNCTIONAL ACTIVITY (0.252+/-0.03 VS 0.698+/-0.02; P<0.001). WE EMPLOY THESE OBSERVATIONS IN CHIP DIFFERENTIAL DISPLAY PCR TO ATTEMPT TO IDENTIFY POTENTIAL FETAL GENES WHOSE EXPRESSION IS REPROGRAMED UNDER CONDITIONS OF A HIGH-FAT MATERNAL DIET. WE QUANTITATIVELY CONFIRM A MINIMUM OF A 40% ALTERATION IN THE EXPRESSION OF SEVERAL GENES OF INTEREST: GLUTAMIC PYRUVATE TRANSAMINASE (ALANINE AMINOTRANSFERASE) 2 (GPT2) (1.59+/-0.23-FOLD; P=0.08), DNAJA2 (1.36+/-0.21; P=0.09), AND RDH12 (1.88+/-0.15; P=0.01) ARE APPRECIABLY INCREASED IN FETAL HEPATIC TISSUE FROM MATERNAL CALORIC-DENSE DIET ANIMALS WHEN COMPARED WITH CONTROL WHILE NPAS2, A PERIPHERAL CIRCADIAN REGULATOR, WAS SIGNIFICANTLY DOWNMODULATED IN THE OFFSPRING OF HIGH-FAT DIET ANIMALS (0.66+/-0.08; P=0.03). IN THIS STUDY, WE SHOW THAT A CURRENT SIGNIFICANT IN UTERO EXPOSURE (CALORIC-DENSE HIGH-FAT MATERNAL DIET) INDUCES SITE-SPECIFIC ALTERATIONS IN FETAL HEPATIC H3 ACETYLATION. EMPLOYING CHIP, WE EXTEND THESE OBSERVATIONS TO LINK MODIFICATIONS OF H3 ACETYLATION WITH ALTERATIONS IN GENE-SPECIFIC EXPRESSION. THESE RESULTS SUGGEST THAT A CALORIC-DENSE MATERNAL DIET LEADING TO OBESITY EPIGENETICALLY ALTERS FETAL CHROMATIN STRUCTURE IN PRIMATES VIA COVALENT MODIFICATIONS OF HISTONES AND HENCE LENDS A MOLECULAR BASIS TO THE FETAL ORIGINS OF ADULT DISEASE HYPOTHESIS. 2008 9 3991 33 LONGITUDINAL EFFECTS OF DEVELOPMENTAL BISPHENOL A, VARIABLE DIET, AND PHYSICAL ACTIVITY ON AGE-RELATED METHYLATION IN BLOOD. RESEARCH INDICATES THAT ENVIRONMENTAL FACTORS CAN ALTER DNA METHYLATION, BUT THE SPECIFIC EFFECTS OF ENVIRONMENTAL EXPOSURES ON EPIGENETIC AGING REMAIN UNCLEAR. HERE, USING A MOUSE MODEL OF HUMAN-RELEVANT EXPOSURES, WE TESTED THE HYPOTHESIS THAT EARLY-LIFE EXPOSURE TO BISPHENOL A (BPA), VARIABLE DIET, AND/OR CHANGES IN PHYSICAL ACTIVITY WOULD MODIFY RATES OF AGE-RELATED METHYLATION AT SEVERAL TARGET REGIONS, AS MEASURED FROM LONGITUDINAL BLOOD SAMPLES (2, 4, AND 10 MONTHS OLD). DNA METHYLATION WAS QUANTIFIED AT TWO REPETITIVE ELEMENTS (LINE-1, IAP), TWO IMPRINTED GENES (IGF2, H19), AND ONE NON-IMPRINTED GENE (ESR1) IN ISOGENIC MICE DEVELOPMENTALLY EXPOSED TO CONTROL, CONTROL + BPA (50 MICROG/KG DIET), WESTERN HIGH-FAT DIET (WHFD), OR WESTERN + BPA DIETS. IN BLOOD SAMPLES, ESR1 DNA METHYLATION INCREASED SIGNIFICANTLY WITH AGE, BUT NO OTHER INVESTIGATED LOCI SHOWED SIGNIFICANT AGE-RELATED METHYLATION. LINE-1 AND IAP BOTH SHOWED SIGNIFICANT NEGATIVE ENVIRONMENTAL DEFLECTION BY WHFD EXPOSURE (P < 0.05). ESR1ALSO SHOWED SIGNIFICANT NEGATIVE ENVIRONMENTAL DEFLECTION BY WHFD EXPOSURE IN FEMALE MICE (P = 0.02), BUT NOT MALE MICE. PHYSICAL ACTIVITY HAD A NON-SIGNIFICANT POSITIVE EFFECT ON AGE-RELATED ESR1 METHYLATION IN FEMALE BLOOD, SUGGESTING THAT IT MAY PARTIALLY ABROGATE THE EFFECTS OF WHFD ON THE AGING EPIGENOME. THESE RESULTS SUGGEST THAT DEVELOPMENTAL NUTRITIONAL EXPOSURES CAN MODIFY AGE-RELATED DNA METHYLATION PATTERNS AT A GENE RELATED TO GROWTH AND DEVELOPMENT. AS SUCH, ENVIRONMENTAL DEFLECTION OF THE AGING EPIGENOME MAY HELP TO EXPLAIN THE GROWING PREVALENCE OF CHRONIC DISEASES IN HUMAN POPULATIONS. 2018 10 891 27 CHRONIC EFFECTS OF CLOFIBRIC ACID IN ZEBRAFISH (DANIO RERIO): A MULTIGENERATIONAL STUDY. CLOFIBRIC ACID (CA) IS AN ACTIVE METABOLITE OF THE BLOOD LIPID LOWERING AGENT CLOFIBRATE, A PHARMACEUTICAL DESIGNED TO WORK AS AGONIST OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA (PPARA). IT IS THE MOST COMMONLY REPORTED FIBRATE IN AQUATIC ENVIRONMENTS WITH LOW DEGRADATION RATE AND POTENTIAL ENVIRONMENTAL PERSISTENCE. PREVIOUS FISH EXPOSURES SHOWED THAT CA MAY IMPACT SPERMATOGENESIS, GROWTH AND THE EXPRESSION OF FAT BINDING PROTEIN GENES. HOWEVER, THERE ARE LIMITED DATA ON THE EFFECTS OF CHRONIC MULTIGENERATIONAL CA EXPOSURES. HERE, WE ASSESSED CHRONIC MULTIGENERATIONAL EFFECTS OF CA EXPOSURE USING ZEBRAFISH (DANIO RERIO) AS A TELEOST MODEL. ZEBRAFISH WERE EXPOSED THROUGH THE DIET TO CA (1 AND 10MG/G) DURING THEIR WHOLE LIFETIME. GROWTH, REPRODUCTION-RELATED PARAMETERS AND EMBRYONIC DEVELOPMENT WERE ASSESSED IN THE EXPOSED FISH (F1 GENERATION) AND THEIR OFFSPRING (F2 GENERATION), TOGETHER WITH MUSCLE TRIGLYCERIDE CONTENT AND GONAD HISTOLOGY. IN ORDER TO STUDY THE POTENTIAL UNDERLYING MECHANISMS, THE TRANSCRIPTION LEVELS OF GENES CODING FOR ENZYMES INVOLVED IN LIPID METABOLISM PATHWAYS WERE DETERMINED. THE RESULTS SHOW THAT CHRONIC LIFE-CYCLE EXPOSURE TO CA INDUCED A SIGNIFICANT REDUCTION IN GROWTH OF F1 GENERATION AND LOWERED TRIGLYCERIDE MUSCLE CONTENT (10MG/G GROUP). ALSO, AN IMPACT IN MALE GONAD DEVELOPMENT WAS OBSERVED TOGETHER WITH A DECREASE IN THE FECUNDITY (10MG/G GROUP) AND HIGHER FREQUENCY OF EMBRYO ABNORMALITIES IN THE OFFSPRING OF FISH EXPOSED TO THE LOWEST CA DOSE. THE PROFILE OF THE TARGET GENES WAS SEX- AND TISSUE-DEPENDENT. IN F1 AN UP-REGULATION OF MALE HEPATIC PPARAA, PPARB AND ACOX TRANSCRIPT LEVELS WAS OBSERVED, SUGGESTING AN ACTIVATION OF THE FATTY ACID METABOLISM (PROVIDED THAT TRANSCRIPT LEVEL CHANGE INDICATES ALSO A PROTEIN LEVEL CHANGE). INTERESTINGLY, THE F2 GENERATION, RAISED WITH CONTROL DIET, DISPLAYED A RESPONSE PATTERN DIFFERENT FROM THAT OBSERVED IN F1, SHOWING AN INCREASE IN WEIGHT IN THE DESCENDANTS OF CA EXPOSED FISH, IN COMPARISON WITH CONTROL ANIMALS, WHICH POINTS TO A MULTIGENERATIONAL EFFECT. 2015 11 5205 24 PRENATAL STRESS CHANGES THE GLYCOPROTEIN GPM6A GENE EXPRESSION AND INDUCES EPIGENETIC CHANGES IN RAT OFFSPRING BRAIN. PRENATAL STRESS (PS) EXERTS STRONG IMPACT ON FETAL BRAIN DEVELOPMENT AND ON ADULT OFFSPRING BRAIN FUNCTIONS. PREVIOUS WORK DEMONSTRATED THAT CHRONIC STRESS ALTERS THE MRNA EXPRESSION OF GPM6A, A NEURONAL GLYCOPROTEIN INVOLVED IN FILOPODIUM EXTENSION. IN THIS WORK, WE ANALYZED THE EFFECT OF PS ON GPM6A EXPRESSION AND THE EPIGENETIC MECHANISMS INVOLVED. PREGNANT WISTAR RATS RECEIVED RESTRAINT STRESS DURING THE LAST WEEK OF GESTATION. MALE OFFSPRING WERE SACRIFICED ON POSTNATAL DAYS 28 AND 60. HIPPOCAMPUS AND PREFRONTAL CORTEX SAMPLES WERE ANALYZED FOR GENE EXPRESSION (QPCR FOR MRNAS AND MICRORNAS), METHYLATION STATUS (BISULFITE CONVERSION) AND PROTEIN LEVELS. HIPPOCAMPAL NEURONS IN CULTURE WERE USED TO ANALYZE MICRORNA OVEREXPRESSION EFFECTS. PRENATAL STRESS INDUCED CHANGES IN GPM6A LEVELS IN BOTH TISSUES AND AT BOTH AGES ANALYZED, INDICATING A PERSISTENT EFFECT. TWO CPG ISLANDS IN THE GPM6A GENE WERE IDENTIFIED. VARIATIONS IN THE METHYLATION PATTERN AT THREE SPECIFIC CPGS WERE FOUND IN HIPPOCAMPUS, BUT NOT IN PFC SAMPLES FROM PS OFFSPRING. MICRORNAS PREDICTED TO TARGET GPM6A WERE IDENTIFIED IN SILICO. QPCR MEASUREMENTS SHOWED THAT PS MODIFIED THE EXPRESSION OF SEVERAL MICRORNAS IN BOTH TISSUES, BEING MICRORNA-133B THE MOST SIGNIFICANTLY ALTERED. FURTHER STUDIES OVEREXPRESSING THIS MICRORNA IN NEURONAL CULTURES SHOWED A REDUCTION IN GMP6A MRNA AND PROTEIN LEVEL. MOREOVER FILOPODIUM DENSITY WAS ALSO REDUCED, SUGGESTING THAT GPM6A FUNCTION WAS AFFECTED. GESTATIONAL STRESS AFFECTED GPM6A GENE EXPRESSION IN OFFSPRING LIKELY THROUGH CHANGES IN METHYLATION STATUS AND IN POSTTRANSCRIPTIONAL REGULATION BY MICRORNAS. THUS, OUR FINDINGS PROPOSE GPM6A AS A NOVEL TARGET FOR EPIGENETIC REGULATION DURING PRENATAL STRESS. 2014 12 4528 17 MULTIGENERATIONAL EFFECTS OF CADMIUM ON THE LIFESPAN AND FERTILITY OF DROSOPHILA MELANOGASTER. ALTHOUGH THE DAMAGE AND TOLERANCE MECHANISMS OF CD STRESS ARE KNOWN, THE DATA ON GENETIC RISK ARE LIMITED. THE AIM OF THIS STUDY WAS TO ASSESS THE CHRONIC TOXICITY OF CD, GENETIC RESPONSES, AND MULTIGENERATIONAL EFFECTS IN FIVE GENERATIONS OF DROSOPHILA MELANOGASTER. FOR EACH GENERATION, LIFESPAN AND FERTILITY WERE STATISTICALLY ANALYSED AND THE EXPRESSION OF APOPTOSIS- (P53 AND CASPASE-3) AND EPIGENESIS-RELATED (DDNMT2 AND DMBD2/3) GENES WAS EXAMINED. LIFESPAN AND FERTILITY SIGNIFICANTLY DECLINED UNDER CD STRESS AND THESE EFFECTS WERE MAINTAINED FOR TWO GENERATIONS AND ONE GENERATION, RESPECTIVELY, WHEN CD STRESS WAS REMOVED. THE EXPRESSION OF P53 AND CASPASE-3 WAS SIGNIFICANTLY UP-REGULATED AFTER EXPOSURE, SUGGESTING THAT APOPTOSIS CONTRIBUTES TO THE RESISTANCE MECHANISM. THEIR ALTERED EXPRESSION WAS RETAINED FOR TWO GENERATIONS. FURTHERMORE, HIGH EXPRESSION OF DDNMT2 AND DMBD2/3 ACCOMPANIED CD EXPOSURE, WHICH WAS PASSED ON TO THREE GENERATIONS, SUGGESTING THAT GENETIC MODIFICATIONS IN APOPTOSIS-RELATED GENES ARE CARRIED TO THE OFFSPRING THROUGH EPIGENETIC REGULATION. 2020 13 1162 23 CONTRASTING EFFECTS OF ACUTE AND CHRONIC STRESS ON THE TRANSCRIPTOME, EPIGENOME, AND IMMUNE RESPONSE OF ATLANTIC SALMON. STRESS EXPERIENCED DURING EARLY LIFE MAY HAVE LASTING EFFECTS ON THE IMMUNE SYSTEM, WITH IMPACTS ON HEALTH AND DISEASE DEPENDENT ON THE NATURE AND DURATION OF THE STRESSOR. THE EPIGENOME IS ESPECIALLY SENSITIVE TO ENVIRONMENTAL STIMULI DURING EARLY LIFE AND REPRESENTS A POTENTIAL MECHANISM THROUGH WHICH STRESS MAY CAUSE LONG-LASTING HEALTH EFFECTS. HOWEVER, THE EXTENT TO WHICH THE EPIGENOME RESPONDS DIFFERENTLY TO CHRONIC VS ACUTE STRESSORS IS UNCLEAR, ESPECIALLY FOR NON-MAMMALIAN SPECIES. WE EXAMINED THE EFFECTS OF ACUTE STRESS (COLD-SHOCK DURING EMBRYOGENESIS) AND CHRONIC STRESS (ABSENCE OF TANK ENRICHMENT DURING LARVAL-STAGE) ON GLOBAL GENE EXPRESSION (USING RNA-SEQ) AND DNA METHYLATION (USING RRBS) IN THE GILLS OF ATLANTIC SALMON (SALMO SALAR) FOUR MONTHS AFTER HATCHING. CHRONIC STRESS INDUCED PRONOUNCED TRANSCRIPTIONAL DIFFERENCES, WHILE ACUTE STRESS CAUSED FEW LASTING TRANSCRIPTIONAL EFFECTS. HOWEVER, BOTH ACUTE AND CHRONIC STRESS CAUSED LASTING AND CONTRASTING CHANGES IN THE METHYLOME. CRUCIALLY, WE FOUND THAT ACUTE STRESS ENHANCED TRANSCRIPTIONAL IMMUNE RESPONSE TO A PATHOGENIC CHALLENGE (BACTERIAL LIPOPOLYSACCHARIDE, LPS), WHILE CHRONIC STRESS SUPPRESSED IT. WE IDENTIFIED STRESS-INDUCED CHANGES IN PROMOTER AND GENE-BODY METHYLATION THAT WERE ASSOCIATED WITH ALTERED EXPRESSION FOR A SMALL PROPORTION OF IMMUNE-RELATED GENES, AND EVIDENCE OF WIDER EPIGENETIC REGULATION WITHIN SIGNALLING PATHWAYS INVOLVED IN IMMUNE RESPONSE. OUR RESULTS SUGGEST THAT STRESS CAN AFFECT IMMUNO-COMPETENCE THROUGH EPIGENETIC MECHANISMS, AND HIGHLIGHT THE MARKEDLY DIFFERENT EFFECTS OF CHRONIC LARVAL AND ACUTE EMBRYONIC STRESS. THIS KNOWLEDGE COULD BE USED TO HARNESS THE STIMULATORY EFFECTS OF ACUTE STRESS ON IMMUNITY, PAVING THE WAY FOR IMPROVED STRESS AND DISEASE MANAGEMENT THROUGH EPIGENETIC CONDITIONING. 2018 14 2808 21 FETAL PROGRAMMING OF HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS FUNCTION AND BEHAVIOR BY SYNTHETIC GLUCOCORTICOIDS. REDUCED FETAL GROWTH HAS BEEN CLOSELY ASSOCIATED WITH AN INCREASED RISK FOR THE DEVELOPMENT OF CHRONIC DISEASE IN LATER LIFE. ACCUMULATING EVIDENCE INDICATES THAT FETAL EXPOSURE TO EXCESS GLUCOCORTICOIDS REPRESENTS A CRITICAL MECHANISM UNDERLYING THIS ASSOCIATION. APPROXIMATELY 7% OF PREGNANT WOMEN ARE AT RISK OF PRETERM DELIVERY AND THESE WOMEN ARE ROUTINELY TREATED WITH SYNTHETIC GLUCOCORTICOIDS (SGC) BETWEEN 24 AND 34 OF WEEKS GESTATION TO IMPROVE NEONATAL OUTCOME. ANIMAL STUDIES HAVE DEMONSTRATED THAT MATERNALLY ADMINISTERED SGC CROSSES THE PLACENTA, AFFECTING FETAL HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) DEVELOPMENT, RESULTING IN CHANGES IN HPA AXIS FUNCTION THAT PERSIST THROUGHOUT LIFE. THESE CHANGES APPEAR TO BE MODULATED AT THE LEVEL OF GLUCOCORTICOID RECEPTORS (GR) AND MINERALOCORTICOID RECEPTORS (MR) IN THE BRAIN AND PITUITARY. AS THE HPA AXIS INTERACTS WITH MANY OTHER PHYSIOLOGICAL PATHWAYS, THE CHANGES IN ENDOCRINE FUNCTION ARE ALSO SEX-SPECIFIC AND AGE-DEPENDENT. ALTERATIONS IN BEHAVIOR, PARTICULARLY LOCOMOTION, IN ANIMALS EXPOSED TO SGC IN UTERO HAVE ALSO BEEN DEMONSTRATED. CONSISTENT WITH THE FINDING IN ANIMAL MODELS, EMERGING HUMAN DATA ARE INDICATING ATTENTION DEFICIT-HYPERACTIVITY DISORDER (ADHD)-LIKE SYMPTOMS IN CHILDREN EXPOSED TO REPEATED COURSES OF SGC IN UTERO. THIS BEHAVIORAL PHENOTYPE IS LIKELY LINKED TO ALTERATIONS IN DOPAMINE (DA) SIGNALING, SUGGESTING THAT SGC ARE ABLE TO PERMANENTLY MODIFY OR 'PROGRAM' THIS SYSTEM. FINALLY, IT IS EMERGING THAT CHANGES IN HPA AXIS FUNCTION AND BEHAVIOR FOLLOWING ANTENATAL EXPOSURE TO SGC ARE TRANSGENERATIONAL AND LIKELY INVOLVE EPIGENETIC MECHANISMS. A COMPREHENSIVE UNDERSTANDING OF THE ACUTE AND LONG-TERM IMPACT OF SGC EXPOSURE IN UTERO IS NECESSARY TO BEGIN TO DEVELOP RECOMMENDATIONS AND TREATMENT OPTIONS FOR PREGNANT WOMEN AT RISK OF PRETERM DELIVERY. 2008 15 2776 24 EXTRAUTERINE GROWTH RESTRICTION ON PULMONARY VASCULAR ENDOTHELIAL DYSFUNCTION IN ADULT MALE RATS: THE ROLE OF EPIGENETIC MECHANISMS. OBJECTIVE: EARLY POSTNATAL LIFE IS CONSIDERED AS A CRITICAL TIME WINDOW FOR THE DETERMINATION OF LONG-TERM METABOLIC STATES AND ORGAN FUNCTIONS. EXTRAUTERINE GROWTH RESTRICTION (EUGR) CAUSES THE DEVELOPMENT OF ADULT-ONSET CHRONIC DISEASES, INCLUDING PULMONARY HYPERTENSION. HOWEVER, THE EFFECTS OF NUTRITIONAL DISADVANTAGES DURING THE EARLY POSTNATAL PERIOD ON PULMONARY VASCULAR CONSEQUENCES IN LATER LIFE ARE NOT FULLY UNDERSTOOD. OUR STUDY WAS DESIGNED TO TEST WHETHER EPIGENETICS DYSREGULATION MEDIATES THE CELLULAR MEMORY OF THIS EARLY POSTNATAL EVENT. METHODS AND RESULTS: TO TEST THIS HYPOTHESIS, WE ISOLATED PULMONARY VASCULAR ENDOTHELIAL CELLS BY MAGNETIC-ACTIVATED CELL SORTING FROM EUGR AND CONTROL RATS. A POSTNATAL INSULT, NUTRITIONAL RESTRICTION-INDUCED EUGR CAUSED DEVELOPMENT OF AN INCREASED PULMONARY ARTERY PRESSURE AT 9 WEEKS OF AGE IN MALE SPRAGUE-DAWLEY RATS. METHYL-DNA IMMUNE PRECIPITATION CHIP, GENOME-SCALE MAPPING STUDIES TO SEARCH FOR DIFFERENTIALLY METHYLATED LOCI BETWEEN CONTROL AND EUGR RATS, REVEALED SIGNIFICANT DIFFERENCE IN CYTOSINE METHYLATION BETWEEN EUGR AND CONTROL RATS. EUGR CHANGES THE CYTOSINE METHYLATION AT APPROXIMATELY 500 LOCI IN MALE RATS AT 9 WEEKS OF AGE, PRECEDING THE DEVELOPMENT OF PULMONARY HYPERTENSION AND THESE REPRESENT THE CANDIDATE LOCI FOR MEDIATING THE PATHOGENESIS OF PULMONARY VASCULAR DISEASE THAT OCCURS LATER IN LIFE. GENE ONTOLOGY ANALYSIS ON DIFFERENTIALLY METHYLATED GENES SHOWED THAT HYPERMETHYLATED GENES IN EUGR ARE VASCULAR DEVELOPMENT-ASSOCIATED GENES AND HYPOMETHYLATED GENES IN EUGR ARE LATE-DIFFERENTIATION-ASSOCIATED AND SIGNAL TRANSDUCTION GENES. WE VALIDATED CANDIDATE DYSREGULATED LOCI WITH THE QUANTITATIVE ASSAYS OF CYTOSINE METHYLATION AND GENE EXPRESSIONS. CONCLUSION: THESE RESULTS DEMONSTRATE THAT EPIGENETICS DYSREGULATION IS A STRONG MECHANISM FOR PROPAGATING THE CELLULAR MEMORY OF EARLY POSTNATAL EVENTS, CAUSING CHANGES IN THE EXPRESSION OF GENES AND LONG-TERM SUSCEPTIBILITY TO PULMONARY HYPERTENSION, AND FURTHER PROVIDING A NEW INSIGHT INTO THE PREVENTION AND TREATMENT OF EUGR-RELATED PULMONARY HYPERTENSION. 2014 16 1174 24 CONTRIBUTION OF TRANSPOSABLE ELEMENTS TO TRANSGENERATIONAL EFFECTS OF CHRONIC RADIOACTIVE EXPOSURE OF NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER LIVING FOR A LONG TIME IN THE ZONE OF THE CHERNOBYL NUCLEAR DISASTER. THE ACCIDENT AT THE CHERNOBYL NUCLEAR POWER PLANT (CHNPP) LED TO THE NEGATIVE IMPACT OF CHRONIC RADIOACTIVE CONTAMINATION ON POPULATIONS OF ORGANISMS ASSOCIATED WITH THE TRANSGENERATIONAL TRANSMISSION OF GENOME INSTABILITY. WHEN THE DESTABILIZATION OF GENOME, DIFFERENT GENETIC DAMAGES OCCUR, THE ACCUMULATION OF WHICH LEADS TO THE FORMATION OF MUTATIONS, MORPHOLOGICAL ANOMALIES, AND MORTALITY IN THE OFFSPRING. THE MECHANISMS UNDERLYING THE MANIFESTATION OF TRANSGENERATIONAL EVENTS IN THE OFFSPRING OF IRRADIATED PARENTS ARE NOT WELL UNDERSTOOD. IN THIS STUDY, FOR THE FIRST TIME, THE FEATURES OF THE INFLUENCE OF TRANSPOSABLE ELEMENTS (TES) ON THE LONG-TERM BIOLOGICAL CONSEQUENCES OF THE CHNPP ARE CONSIDERED. IN THIS WORK, SPECIMENS OF D. MELANOGASTER OBTAINED FROM NATURAL POPULATIONS IN 2007 IN THE AREAS OF THE CHNPP WITH HETEROGENEOUS RADIOACTIVE CONTAMINATION WERE STUDIED. THE DESCENDANTS FROM THESE POPULATIONS WERE MAINTAINED IN LABORATORY (INBRED) CONDITIONS FOR 160 GENERATIONS. A STABLE TRANSGENERATIONAL TRANSMISSION OF DOMINANT LETHAL MUTATIONS (DLMS) TO THE OFFSPRING OF ALL STUDIED POPULATIONS WAS SHOWN. THE DLM FREQUENCIES STRONGLY WERE CORRELATED WITH THE LEVEL OF SURVIVAL OF OFFSPRING. THE MEAN FREQUENCIES OF RECESSIVE SEX-LINKED LETHAL MUTATIONS VARIED AT THE LEVEL OF SPONTANEOUS POINT MUTATIONS. THE SIMULTANEOUS PRESENCE OF P, HOBO AND I ELEMENTS INDICATES THAT THE STUDIED POPULATIONS DO NOT HAVE A DEFINITE CYTOTYPE, THEIR PHENOTYPIC STATUS IS UNSTABLE. THE BEHAVIOR OF TES IN THE GENOMES OF OFFSPRING DEPENDS NOT ONLY ON PARENTAL EXPOSURE, BUT ALSO ON ORIGIN OF POPULATION, DISTANCE TO THE CHNPP, AND INBRED CONDITIONS. THE OBTAINED RESULTS CONFIRM THE HYPOTHESIS THAT TES ARE INVOLVED IN TRANSGENERATIONAL TRANSMISSION AND ACCUMULATION OF MUTATIONS BY THE OFFSPRING OF IRRADIATED PARENTS. THE TES PATTERN PRESENT IN THE CHERNOBYL GENOMES OF D. MELANOGASTER IS A PECULIAR OF EPIGENETIC MECHANISM FOR THE REGULATION OF PLASTICITY AND ADAPTATION OF POPULATIONS LIVING FOR MANY GENERATIONS UNDER CONDITIONS OF A TECHNOGENICALLY CAUSED RADIATION BACKGROUND. 2022 17 4019 24 LOW-DOSE OR LOW-DOSE-RATE IONIZING RADIATION-INDUCED BIOEFFECTS IN ANIMAL MODELS. ANIMAL EXPERIMENTAL STUDIES INDICATE THAT ACUTE OR CHRONIC LOW-DOSE IONIZING RADIATION (LDIR) (