1 4923 128 PARENTAL DIURON EXPOSURE CAUSES LOWER HATCHABILITY AND ABNORMAL OVARIAN DEVELOPMENT IN OFFSPRING OF MEDAKA (ORYZIAS MELASTIGMA). DIURON IS ONE OF THE MOST WIDELY USED HERBICIDES WORLDWIDE. IT HAS BEEN WIDELY DETECTED IN VARIOUS AQUATIC ENVIRONMENTS, ESPECIALLY IN MARINE ECOSYSTEMS. ALTHOUGH DIRECT EFFECTS OF DIURON EXPOSURE ON VARIOUS ORGANISMS HAVE BEEN REPORTED, LITTLE IS KNOWN ABOUT ITS EFFECTS ON MARINE FISHES INCLUDING MULTIGENERATIONAL EFFECTS. HEREIN, THE FILIAL GENERATION (F1) OF DIURON-EXPOSED MARINE MEDAKA (ORYZIAS MELASTIGMA) (F0) WAS RAISED IN CLEAN SEAWATER FROM FERTILIZED EGGS TO ADULTHOOD AND USED AS A MARINE FISH MODEL TO STUDY THE POTENTIAL MULTIGENERATIONAL EFFECTS OF DIURON. WE FOUND THAT THE SUCCESSFUL HATCHING OF F1 LARVAE WAS SIGNIFICANTLY REDUCED AND THAT OVARIAN DEVELOPMENT IN F1 FEMALES WAS RETARDED. A SIGNIFICANT INCREASE IN THE PERCENTAGE OF PREVITELLOGENIC OOCYTES, ALONG WITH A VISUAL DECREASE IN THE PERCENTAGE OF VITELLOGENIC AND MATURE OOCYTES IN THE F1 OVARY, WERE OBSERVED. THE HORMONE LEVELS OF THE HYPOTHALAMUS-PITUITARY-GONAD-LIVER AXIS AND VITELLOGENIN-RELATED TRANSCRIPTION WERE DOWNREGULATED. IN ADDITION, THE MRNA LEVELS OF DNA METHYLTRANSFERASE IN THE BRAIN, OVARY AND LIVER OF F1 ADULT FISH EXHIBITED SIGNIFICANT UPREGULATION, SUGGESTING THAT THE PROBABLE UNDERLYING MULTIGENERATIONAL MECHANISM MIGHT BE ASSOCIATED WITH EPIGENETIC MODIFICATIONS. TAKEN TOGETHER, THESE RESULTS DEMONSTRATED THAT CHRONIC ENVIRONMENTAL DIURON EXPOSURE IN F0 MARINE MEDAKA CAN INHIBIT F1 OVARY DEVELOPMENT AND SUGGESTED THAT DIURON MAY AFFECT MARINE FISH THRIVING IN THE OCEAN. 2022 2 3109 34 GENOTOXIC AND EPIGENETIC EFFECTS OF DIURON IN THE PACIFIC OYSTER: IN VITRO EVIDENCE OF INTERACTION BETWEEN DNA DAMAGE AND DNA METHYLATION. RECENTLY, RESEARCH HAS CONTRIBUTED TO BETTER KNOWLEDGE ON THE OCCURRENCE OF PESTICIDES IN COASTAL WATER BY IDENTIFYING FREQUENTLY DETECTED SUBSTANCES, THEIR CONCENTRATION RANGE AND THEIR ACUTE AND CHRONIC TOXICITY FOR ORGANISMS. PESTICIDE POLLUTION IS OF PARTICULAR CONCERN IN FRANCE DUE TO IMPORTANT AGRICULTURAL ACTIVITIES AND PRESENCE OF SEVERAL EXOREIC CATCHMENT AREAS THAT VEHICLE PESTICIDES UP TO COASTAL WATERS, IMPACTING NON-TARGET MARINE SPECIES. SEVERAL ECOTOXICOLOGY QUESTIONS REMAIN TO BE ADDRESSED CONCERNING THE LONG-TERM EFFECTS OF CHRONIC PESTICIDE EXPOSURE AND THE MECHANISMS INVOLVED IN ADAPTATION TO CHEMICAL STRESS. IN THE PRESENT STUDY, WE BROUGHT NEW INSIGHTS ON THE GENETIC AND EPIGENETIC EFFECTS OF THE HERBICIDE DIURON IN OYSTER GENITORS. DURING GAMETOGENESIS, WE EXPOSED CRASSOSTREA GIGAS TO ENVIRONMENTALLY REALISTIC HERBICIDE CONCENTRATIONS (0.2-0.3 MUG L(-1) DURING TWO 7-DAY PERIODS AT HALF-COURSE AND END OF GAMETOGENESIS). DIURON EXPOSURE WAS SHOWN TO DECREASE GLOBAL DNA METHYLATION AND TOTAL METHYLTRANSFERASE ACTIVITY IN WHOLE OYSTER TISSUE; THIS IS CONSISTENT WITH THE PREVIOUS OBSERVATION OF A SIGNIFICANT DECREASE IN DNMT1 GENE EXPRESSION. DIURON EFFECT SEEMED TO BE TISSUE-SPECIFIC; HYPERMETHYLATION WAS DETECTED IN THE DIGESTIVE GLAND, WHEREAS DIURON EXPOSURE HAD NO EFFECT ON GILL AND GONAD TISSUE. THE GENOTOXICITY OF DIURON WAS CONFIRMED BY THE DETECTION OF ONE ADDUCT IN GONAD DNA. BY USING IN VITRO APPROACHES AND HUMAN DNMT1 (DNMT1 HAS NOT BEEN PURIFIED YET IN BIVALVES), THE PRESENCE OF DNA LESIONS (ADDUCT, 8-OXODGUO) WAS SHOWN TO INTERFERE WITH DNMT1 ACTIVITY, INDICATING A COMPLEX INTERACTION BETWEEN DNA DAMAGE AND DNA METHYLATION. BASED ON OUR RESULTS, WE PROPOSE MECHANISMS TO EXPLAIN THE EFFECT OF DIURON EXPOSURE ON DNA METHYLATION, A WIDESPREAD EPIGENETIC MARK. 2021 3 166 38 ABNORMAL OVARIAN DNA METHYLATION PROGRAMMING DURING GONAD MATURATION IN WILD CONTAMINATED FISH. THERE IS INCREASING EVIDENCE THAT POLLUTANTS MAY CAUSE DISEASES VIA EPIGENETIC MODIFICATIONS. EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION PARTICIPATE IN THE REGULATION OF GENE TRANSCRIPTION. SURPRISINGLY, EPIGENETICS RESEARCH IS STILL LIMITED IN ECOTOXICOLOGY. IN THIS STUDY, WE INVESTIGATED WHETHER CHRONIC EXPOSURE TO CONTAMINANTS EXPERIENCED BY WILD FEMALE FISH (ANGUILLA ANGUILLA) THROUGHOUT THEIR JUVENILE PHASE CAN AFFECT THE DNA METHYLATION STATUS OF THEIR OOCYTES DURING GONAD MATURATION. THUS, FISH WERE SAMPLED IN TWO LOCATIONS PRESENTING A LOW OR A HIGH CONTAMINATION LEVEL. THEN, FISH WERE TRANSFERRED TO THE LABORATORY AND ARTIFICIALLY MATURED. BEFORE HORMONAL TREATMENT, THE DNA METHYLATION LEVELS OF THE GENES ENCODING FOR THE AROMATASE AND THE RECEPTOR OF THE FOLLICLE STIMULATING HORMONE WERE HIGHER IN CONTAMINATED FISH THAN IN FISH FROM THE CLEAN SITE. FOR THE HORMONE RECEPTOR, THIS HYPERMETHYLATION WAS POSITIVELY CORRELATED WITH THE CONTAMINATION LEVEL OF FISH AND WAS ASSOCIATED WITH A DECREASE IN ITS TRANSCRIPTION LEVEL. IN ADDITION, WHEREAS GONAD GROWTH WAS ASSOCIATED WITH AN INCREASE IN DNA METHYLATION IN FISH FROM THE CLEAN SITE, NO CHANGES WERE OBSERVED IN CONTAMINATED FISH IN RESPONSE TO HORMONAL TREATMENT. FINALLY, A HIGHER GONAD GROWTH WAS OBSERVED IN FISH FROM THE REFERENCE SITE IN COMPARISON TO CONTAMINATED FISH. 2014 4 73 34 A MULTI-GENERATIONAL STUDY ON LOW-DOSE BPA EXPOSURE IN WISTAR RATS: EFFECTS ON MATERNAL BEHAVIOR, FLAVOR INTAKE AND DEVELOPMENT. BISPHENOL A (BPA) IS A COMMON ENDOCRINE DISRUPTOR FOUND AS AN ENVIRONMENTAL AND FOOD CONTAMINANT. IT EXERTS BOTH DEVELOPMENTAL AND BEHAVIORAL EFFECTS, MAINLY WHEN EXPOSURE OCCURS IN EARLY LIFE. THE AIM OF THIS STUDY WAS TO DETERMINE THE MULTI-GENERATIONAL EFFECTS OF CHRONIC, HUMAN-RELEVANT LOW-DOSE EXPOSURE TO BPA ON DEVELOPMENT, MATERNAL BEHAVIOR AND FLAVOR PREFERENCE IN WISTAR RATS. BPA WAS ORALLY ADMINISTERED AT A DAILY DOSE OF 5 MUG/KG BODY WEIGHT TO F0 PREGNANT DAMS FROM THE FIRST DAY OF GESTATION (GD 1) UNTIL THE LAST DAY OF LACTATION (LD 21), AND THEN TO F1 OFFSPRING FROM WEANING (PND 21) TO ADULTHOOD (PND 100). F2 OFFSPRING WERE NOT EXPOSED. DEVELOPMENT AND CLINICAL SIGNS OF TOXICITY WERE ASSESSED DAILY. MATERNAL BEHAVIOR WAS EVALUATED BY OBSERVING NURSING AND PUP-CARING ACTIONS, AS WELL AS "NON-MATERNAL" BEHAVIORS IN F0 AND F1 DAMS FROM PARTURITION UNTIL LD 8. THE FLAVOR PREFERENCES OF F1 AND F2 OFFSPRING WERE EVALUATED BASED ON THE INTAKE OF SWEET, SALT AND FAT SOLUTIONS USING THE TWO-BOTTLE CHOICE TEST ON PND 21-34 AND PND 86-99. BPA EXPOSURE: 1) DECREASED MATERNAL BEHAVIOR IN F1 DAMS, 2) CAUSED DEVELOPMENTAL DEFECTS IN BOTH F1 AND F2 OFFSPRING, WITH A NOTICEABLE DECREASE IN ANOGENITAL DISTANCE IN MALE RATS, AND 3) DID NOT AFFECT FLAVORED SOLUTION INTAKE IN F1, BUT INDUCED CHANGES IN SWEET PREFERENCE IN F2 JUVENILES AND IN SALT AND FAT SOLUTION INTAKES IN F2 ADULTS, AND 4) INDUCED A BODY WEIGHT INCREASE IN THE F2 GENERATION ONLY, WHEREAS FOOD INTAKE AND WATER CONSUMPTION DID NOT CHANGE. TAKEN AS A WHOLE, OUR FINDINGS SHOWED THAT BOTH GESTATIONAL (F0) AND LIFELONG (F1) EXPOSURES TO A HUMAN-RELEVANT DOSE OF BPA COULD INDUCE MULTI-GENERATIONAL EFFECTS ON BOTH DEVELOPMENT AND BEHAVIOR. THESE RESULTS SUGGEST POSSIBLE SELECTIVE NEUROENDOCRINE DEFECTS AND/OR EPIGENETIC CHANGES CAUSED BY BPA EXPOSURE. 2014 5 2484 47 EPIGENETIC, TRANSCRIPTIONAL AND PHENOTYPIC RESPONSES IN TWO GENERATIONS OF DAPHNIA MAGNA EXPOSED TO THE DNA METHYLATION INHIBITOR 5-AZACYTIDINE. THE WATER FLEA DAPHNIA MAGNA IS A KEYSTONE SPECIES IN FRESHWATER ECOSYSTEMS AND HAS BEEN WIDELY USED AS A MODEL ORGANISM IN ENVIRONMENTAL ECOTOXICOLOGY. THIS AQUATIC CRUSTACEAN IS SENSITIVE TO ENVIRONMENTAL STRESSORS AND DISPLAYS CONSIDERABLE PLASTICITY IN ADAPTING TO CHANGING ENVIRONMENTAL CONDITIONS. PART OF THIS PLASTICITY MAY BE DUE TO EPIGENETIC REGULATION OF GENE EXPRESSION, INCLUDING CHANGES TO DNA METHYLATION AND HISTONE MODIFICATIONS. BECAUSE OF THE GENERALLY HYPOMETHYLATED GENOME OF THIS SPECIES, WE HYPOTHESIZED THAT THE HISTONE CODE MAY HAVE AN ESSENTIAL ROLE IN THE EPIGENETIC CONTROL AND THAT HISTONE MODIFICATIONS MIGHT BE AN EARLY MARKER FOR STRESS. THIS STUDY AIMS TO CHARACTERIZE THE EPIGENETIC, TRANSCRIPTIONAL AND PHENOTYPIC RESPONSES AND THEIR CAUSAL LINKAGES IN DIRECTLY EXPOSED ADULT (F0) DAPHNIA AND PERITONEAL EXPOSED NEONATES (F1) AFTER A CHRONIC (7-DAY) EXPOSURE TO A SUBLETHAL CONCENTRATION (10 MG/L) OF 5-AZACYTIDINE, A WELL-STUDIED VERTEBRATE DNA METHYLATION INHIBITOR. EXPOSURE OF THE F0 GENERATION SIGNIFICANTLY REDUCED THE CUMULATIVE FECUNDITY, ACCOMPANIED WITH DIFFERENTIAL EXPRESSION OF GENES IN THE ONE-CARBON-CYCLE METABOLIC PATHWAY. IN THE EPIGENOME OF THE F0 GENERATION, A DECREASE IN GLOBAL DNA METHYLATION, BUT NO SIGNIFICANT CHANGES ON H3K4ME3 OR H3K27ME3, WERE OBSERVED. IN THE F1 OFFSPRING GENERATION, CHANGES IN GENE EXPRESSION, A SIGNIFICANT REDUCTION IN GLOBAL DNA METHYLATION AND CHANGES IN HISTONE MODIFICATIONS WERE IDENTIFIED. THE RESULTS INDICATE THAT EXPOSURE DURING ADULTHOOD MAY RESULT IN MORE PRONOUNCED EFFECTS ON EARLY DEVELOPMENT IN THE OFFSPRING GENERATION, THOUGH INTERPRETATION OF THE DATA SHOULD BE CAREFULLY DONE SINCE BOTH THE EXPOSURE REGIME AND DEVELOPMENTAL PERIOD IS DIFFERENT IN THE TWO GENERATIONS EXAMINED. THE OBTAINED RESULTS IMPROVE OUR UNDERSTANDING OF CRUSTACEAN EPIGENETICS AND THE TOOLS DEVELOPED MAY PROMOTE USE OF EPIGENETIC MARKERS IN HAZARD ASSESSMENT OF ENVIRONMENTAL STRESSORS. 2019 6 6553 39 TRANSGENERATIONAL EFFECTS IN DNA METHYLATION, GENOTOXICITY AND REPRODUCTIVE PHENOTYPE BY CHRONIC ARSENIC EXPOSURE. AN EMERGING CONCERN IS THE INFLUENCES OF EARLY LIFE EXPOSURE TO ENVIRONMENTAL TOXICANTS ON OFFSPRING CHARACTERISTICS IN LATER LIFE. SINCE RECENT EVIDENCE SUGGESTS A TRANSGENERATIONAL TRANSFERENCE OF ABERRANT PHENOTYPES FROM EXPOSED-PARENTS TO NON-EXPOSED OFFSPRING RELATED TO ADULT-ONSET DISEASES INCLUDING REPRODUCTIVE PHENOTYPE. THE TRANSGENERATIONAL POTENTIAL OF ARSENIC A WELL KNOW GENOTOXIC AND EPIGENETIC MODIFIER AGENT HAS NOT BEEN ASSESSED IN MAMMALS UNTIL NOW. IN THIS EXPERIMENTAL STUDY, WE EVALUATED THE TRANSGENERATIONAL EFFECTS OF ARSENIC IN A RAT MODEL WITH CHRONIC EXPOSURE TO ARSENIC. RATS CHRONICALLY EXPOSED TO ARSENIC IN DRINKING WATER (1 MG AS(2)O(3)/ML) (F0) WERE MATED TO PRODUCE THE ARSENIC LINEAGE (F1, F2, AND F3). THE ARSENIC TOXIC EFFECTS ON WERE EVALUATED OVER THE FOUR GENERATIONS BY ANALYZING THE DNA METHYLATION PERCENTAGE, GENOTOXICITY IN WBC AND PHYSICAL AND REPRODUCTIVE PARAMETERS, INCLUDING SPERM QUALITY PARAMETERS AND HISTOPATHOLOGICAL EVALUATION OF THE GONADS. CHRONIC EXPOSURE TO ARSENIC CAUSED GENOTOXIC DAMAGE (F0-F3) DIFFERENT METHYLATION PATTERNS, ALTERATIONS IN PHYSICAL AND REPRODUCTIVE PARAMETERS, ABERRANT MORPHOLOGY IN THE OVARIES (F0 AND F1) AND TESTICLES (F1-F3), AND A DECREASE IN THE QUALITY OF SPERM (F0-F3, EXCEPT F2). PARENTAL CHRONIC ARSENIC EXPOSURE CAUSES TRANSGENERATIONAL GENOTOXICITY AND CHANGES IN GLOBAL DNA METHYLATION WHICH MIGHT BE ASSOCIATED WITH REPRODUCTIVE DEFECTS IN RATS. COMBINED WITH RECENT STUDIES REVEAL THAT DISTURBANCES IN THE EARLY LIFE OF AN INDIVIDUAL CAN AFFECT THE HEALTH OF LATER GENERATIONS. 2021 7 4008 32 LOW DOSE OF URANIUM INDUCES MULTIGENERATIONAL EPIGENETIC EFFECTS IN RAT KIDNEY. PURPOSE: A PROTOCOL OF CHRONIC EXPOSURE TO LOW DOSE OF URANIUM WAS ESTABLISHED IN ORDER TO DISTINGUISH THE SEXUAL DIFFERENCES AND THE DEVELOPMENTAL PROCESS THAT ARE CRITICAL WINDOWS FOR EPIGENETIC EFFECTS OVER GENERATIONS. METHODS: BOTH MALE AND FEMALE RATS WERE CONTAMINATED THROUGH THEIR DRINKING WATER WITH A NON-TOXIC SOLUTION OF URANYL NITRATE FOR 9 MONTHS. THE EXPOSED GENERATION (F0) AND THE FOLLOWING TWO GENERATIONS (F1 AND F2) WERE EXAMINED. CLINICAL MONITORING, GLOBAL DNA METHYLATION PROFILE AND DNA METHYLTRANSFERASES (DNMTS) GENE EXPRESSION WERE ANALYZED IN KIDNEYS. RESULTS: WHILE THE BODY WEIGHT OF F1 MALES INCREASED, A SMALL DECREASE IN KIDNEY AND BODY WEIGHT WAS OBSERVED IN F2 MALES. IN ADDITION, GLOBAL DNA HYPERMETHYLATION PROFILE IN KIDNEY CELLS WAS OBSERVED IN F1 AND F2 MALES. QPCR RESULTS REVEAL A SIGNIFICANT INCREASE OF METHYLTRANSFERASE GENES EXPRESSION (DNMT1 AND DNMT3A) FOR F2 FEMALES. CONCLUSIONS: IN THE FIELD OF PUBLIC HEALTH POLICY AND TO RAISE ATTENTION TO GENERATIONAL EFFECTS FOR THE RISK ASSESSMENT OF THE ENVIRONMENTAL EXPOSURES, LOW DOSES OF URANIUM DO NOT IMPLY CLINICAL EFFECTS ON ADULT EXPOSED RATS. HOWEVER, OUR RESULTS CONFIRM THE IMPORTANCE OF THE DEVELOPMENTAL WINDOWS' SENSITIVITY IN ADDITION TO THE SEXUAL DIMORPHISMS OF THE OFFSPRING. 2018 8 934 27 CHRONIC LOW DOSE IRRADIATION ALTERS HEPATIC TRANSCRIPTIONAL PROFILES, BUT NOT GLOBAL DNA METHYLATION IN MEDAKA (ORYZIAS LATIPES). IONIZING RADIATION (IR) RESULTING FROM BOTH NATURAL AND ANTHROPOGENIC SOURCES IS UBIQUITOUS THROUGHOUT THE ENVIRONMENT. HISTORICALLY, STUDIES ON THE BIOLOGICAL IMPACTS OF RADIATION PRIMARILY FOCUSED ON RESPONSES TO ACUTE DOSES OF RADIATION, WITH LITTLE ADVANCEMENT IN OUR UNDERSTANDING OF ENVIRONMENTALLY RELEVANT EXPOSURES. EPIGENETIC MECHANISMS ARE CAPABLE OF MEDIATING ORGANISMAL RESPONSES TO ENVIRONMENTAL STRESSORS AND DNA METHYLATION PLAYS IMPORTANT ROLES IN GENE REGULATION AND PROMOTING CHROMOSOMAL STABILITY. HERE, WE ASSESS BROAD-SCALE TRANSCRIPTIONAL AND EPIGENETIC VARIATION RESULTING FROM CHRONIC EXPOSURE TO LOW DOSES OF IONIZING RADIATION (LDIR; 5.78, 53.76, OR 520.23 MGY/DAY) USING JAPANESE MEDAKA FISH (ORYZIAS LATIPES) IN A REPLICATED MESOCOSM DESIGN. WE OBSERVED SIGNIFICANT CHANGES TO THE HEPATIC TRANSCRIPTOME INDUCED BY A 3-MONTH CHRONIC EXPOSURE TO IR, WHEREAS GLOBAL DNA METHYLATION APPEARED LARGELY UNAFFECTED. OUR FINDINGS REVEAL A SET OF GENES, INCLUDING THOSE INVOLVED IN IMMUNE FUNCTION, RESPONDING TO ENVIRONMENTALLY RELEVANT IR EXPOSURES, WHICH DO NOT APPEAR TO BE MEDIATED BY A SYSTEMIC GLOBAL SHIFT IN DNA METHYLATION. 2020 9 6552 33 TRANSGENERATIONAL DNA METHYLATION CHANGES IN DAPHNIA MAGNA EXPOSED TO CHRONIC GAMMA IRRADIATION. OUR AIM WAS TO INVESTIGATE EPIGENETIC CHANGES IN DAPHNIA MAGNA AFTER A 25-DAY CHRONIC EXTERNAL GAMMA IRRADIATION (GENERATION F0 EXPOSED TO 6.5 MUGY.H(-1) OR 41.3 MGY.H(-1)) AND THEIR POTENTIAL INHERITANCE BY SUBSEQUENT RECOVERING GENERATIONS, NAMELY, F2 (EXPOSED AS GERMLINE CELLS IN F1 EMBRYOS) AND F3 (THE FIRST TRULY UNEXPOSED GENERATION). EFFECTS ON SURVIVAL, GROWTH, AND REPRODUCTION WERE OBSERVED AND DNA WAS EXTRACTED FOR WHOLE-GENOME BISULFITE SEQUENCING IN ALL GENERATIONS. RESULTS SHOWED EFFECTS ON REPRODUCTION IN F0 BUT NO EFFECT IN THE SUBSEQUENT GENERATIONS F1, F2, AND F3. IN CONTRAST, WE OBSERVED SIGNIFICANT METHYLATION CHANGES AT SPECIFIC CPG POSITIONS IN EVERY GENERATION INDEPENDENT OF DOSE RATE, WITH A MAJORITY OF HYPOMETHYLATION. SOME OF THESE CHANGES WERE SHARED BETWEEN DOSE RATES AND BETWEEN GENERATIONS. ASSOCIATED GENE FUNCTIONS INCLUDED GENE FAMILIES AND GENES THAT WERE PREVIOUSLY SHOWN TO PLAY ROLES DURING EXPOSURE TO IONIZING RADIATION. COMMON METHYLATION CHANGES DETECTED BETWEEN GENERATIONS F2 AND F3 CLEARLY SHOWED THAT EPIGENETIC MODIFICATIONS CAN BE TRANSMITTED TO UNEXPOSED GENERATIONS, MOST LIKELY THROUGH THE GERMLINE, WITH POTENTIAL IMPLICATIONS FOR ENVIRONMENTAL RISK. 2018 10 3304 41 HIGH-GLUCOSE CONCENTRATIONS CHANGE DNA METHYLATION LEVELS IN HUMAN IVM OOCYTES. STUDY QUESTION: WHAT ARE THE EFFECTS OF HIGH-GLUCOSE CONCENTRATIONS ON DNA METHYLATION OF HUMAN OOCYTES? SUMMARY ANSWER: HIGH-GLUCOSE CONCENTRATIONS ALTERED DNA METHYLATION LEVELS OF PEG3 AND ADIPONECTIN IN HUMAN IN VITRO MATURATION OOCYTES. WHAT IS KNOWN ALREADY: MATERNAL DIABETES HAS A DETRIMENTAL INFLUENCE ON OOCYTE QUALITY INCLUDING EPIGENETIC MODIFICATIONS, AS SHOWN IN NON-HUMAN MAMMALIAN SPECIES. STUDY DESIGN, SIZE, DURATION: IMMATURE METAPHASE I (MI) STAGE OOCYTES OF GOOD QUALITY WERE RETRIEVED FROM PATIENTS WHO HAD NORMAL OVARIAN POTENTIAL AND WHO UNDERWENT ICSI IN THE REPRODUCTIVE MEDICINE CENTER OF PEOPLE'S HOSPITAL OF ZHENGZHOU UNIVERSITY. MI OOCYTES WERE CULTURED IN MEDIUM WITH DIFFERENT GLUCOSE CONCENTRATIONS (CONTROL, 10 MM AND 15 MM) IN VITRO AND 48 H LATER, OOCYTES WITH FIRST POLAR BODY EXTRUSION WERE COLLECTED TO CHECK THE DNA METHYLATION LEVELS. PARTICIPANTS/MATERIALS, SETTING, METHODS: MI OOCYTES UNDERWENT IN VITRO MATURATION (IVM) AT 37 DEGREES C WITH 5% MIXED GAS FOR 48 H. THEN THE MATURE OOCYTES WERE TREATED WITH BISULFITE BUFFER. TARGET SEQUENCES WERE AMPLIFIED USING NESTED OR HALF-NESTED PCR AND THE DNA METHYLATION STATUS WAS TESTED USING COMBINED BISULFITE RESTRICTION ANALYSIS (COBRA) AND BISULFITE SEQUENCING (BS). MAIN RESULTS AND THE ROLE OF CHANCE: HIGH-GLUCOSE CONCENTRATIONS SIGNIFICANTLY DECREASED THE FIRST POLAR BODY EXTRUSION RATE. COMPARED TO CONTROLS, THE DNA METHYLATION LEVELS OF PEG3 IN HUMAN IVM OOCYTES WERE SIGNIFICANTLY HIGHER IN 10 MM (P < 0.001) AND 15 MM (P < 0.001) CONCENTRATIONS OF GLUCOSE. BUT THE DNA METHYLATION LEVEL OF H19 WAS NOT AFFECTED BY HIGH-GLUCOSE CONCENTRATIONS IN HUMAN IVM OOCYTES. WE ALSO FOUND THAT THERE WAS A DECREASE IN DNA METHYLATION LEVELS IN THE PROMOTER OF ADIPONECTIN IN HUMAN IVM OOCYTES BETWEEN CONTROLS AND OOCYTES EXPOSED TO 10 MM GLUCOSE (P = 0.028). LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: IT IS NOT CLEAR WHETHER THE ALTERATIONS ARE BENEFICIAL OR NOT FOR THE EMBRYO DEVELOPMENT AND OFFSPRING HEALTH. THE EFFECTS OF HIGH-GLUCOSE CONCENTRATIONS ON THE WHOLE PROCESS OF OOCYTE MATURATION ARE STILL NOT ELUCIDATED. ANOTHER ISSUE IS THAT THE NUMBER OF OOCYTES USED IN THIS STUDY WAS LIMITED. WIDER IMPLICATIONS OF THE FINDINGS: THIS IS THE FIRST TIME THAT THE EFFECTS OF HIGH-GLUCOSE CONCENTRATION ON DNA METHYLATION OF HUMAN OOCYTES HAVE BEEN ELUCIDATED. OUR RESULT INDICATES THAT IN HUMANS, THE HIGH RISK OF CHRONIC DISEASES IN OFFSPRING FROM DIABETIC MOTHERS MAY ORIGINATE FROM ABNORMAL DNA MODIFICATIONS IN OOCYTES. STUDY FUNDING/COMPETING INTEREST(S): THIS WORK WAS SUPPORTED BY THE FUND OF NATIONAL NATURAL SCIENCE FOUNDATION OF CHINA (81401198) AND DOCTOR FOUNDATION OF QINGDAO AGRICULTURAL UNIVERSITY (1116008).THE AUTHORS DECLARE THAT THERE ARE NO POTENTIAL CONFLICTS OF INTEREST RELEVANT TO THIS ARTICLE. 2018 11 2698 37 EXAMINING MULTI- AND TRANSGENERATIONAL BEHAVIORAL AND MOLECULAR ALTERATIONS RESULTING FROM PARENTAL EXPOSURE TO AN ENVIRONMENTAL PCB AND PBDE MIXTURE. POLYCHLORINATED BIPHENYLS (PCBS) AND POLYBROMINATED DIPHENYL ETHERS (PBDES) ARE PERSISTENT ORGANIC POLLUTANTS EXTENSIVELY USED DURING THE 20(TH) CENTURY AND STILL PRESENT IN AQUATIC ENVIRONMENTS DESPITE THEIR BAN. EFFECTS OF EXPOSURE TO THESE COMPOUNDS OVER GENERATIONS ARE POORLY DOCUMENTED. THEREFORE, OUR AIMS WERE TO CHARACTERIZE BEHAVIORAL RESPONSES AND UNDERLYING MOLECULAR MECHANISMS IN ZEBRAFISH EXPOSED TO AN ENVIRONMENTALLY RELEVANT MIXTURE OF PCBS AND PBDES AS WELL AS IN FOUR UNEXPOSED OFFSPRING GENERATIONS. ZEBRAFISH (F0) WERE CHRONICALLY EXPOSED FROM THE FIRST MEAL ONWARD TO A DIET SPIKED WITH A MIXTURE CONTAINING 22 PCB AND 7 PBDE CONGENERS IN PROPORTIONS AND CONCENTRATIONS REFLECTING ENVIRONMENTAL SITUATIONS (SIGMAPCBS = 1991 AND SIGMAPBDES = 411 NG/G). FOUR OFFSPRING GENERATIONS (F1 TO F4) WERE OBTAINED FROM THIS F0 AND WERE NOT FURTHER EXPOSED. BEHAVIOR WAS ASSESSED AT BOTH LARVAL AND ADULT STAGES. MECHANISMS RELATED TO BEHAVIORAL DEFECTS (HABENULA MATURATION AND C-FOS TRANSCRIPTION) AND METHYLATION (DNMTS TRANSCRIPTION) WERE MONITORED IN LARVAE. EXPOSED ADULT F0 AS WELL AS F1 AND F3 ADULTS DISPLAYED NO BEHAVIORAL CHANGE WHILE F2 EXPRESSED ANXIETY-LIKE BEHAVIOR. LARVAL BEHAVIOR WAS ALSO DISRUPTED, I.E. HYPERACTIVE AFTER LIGHT TO DARK TRANSITION IN F1 OR HYPOACTIVE IN F2, F3 AND F4. BEHAVIORAL DISRUPTIONS MAY BE RELATED TO DEFECT IN HABENULA MATURATION (OBSERVED IN F1) AND CHANGE IN C-FOS TRANSCRIPTION (OBSERVED IN F1 AND F2). TRANSCRIPTION OF THE GENE ENCODING DNA METHYLTRANSFERASE (DNMT3BA) WAS ALSO MODIFIED IN ALL GENERATIONS. OUR RESULTS LEAD US TO HYPOTHESIZE THAT CHRONIC DIETARY EXPOSURE TO AN ENVIRONMENTALLY RELEVANT MIXTURE OF PCB AND PBDE TRIGGERS MULTIGENERATIONAL AND TRANSGENERATIONAL MOLECULAR AND BEHAVIORAL DISRUPTIONS IN A VERTEBRATE MODEL. 2019 12 891 46 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 13 4939 37 PATERNAL NICOTINE EXPOSURE IN RATS PRODUCES LONG-LASTING NEUROBEHAVIORAL EFFECTS IN THE OFFSPRING. STUDIES OF INTERGENERATIONAL EFFECTS OF PARENTAL CHEMICAL EXPOSURE HAVE PRINCIPALLY FOCUSED ON MATERNAL EXPOSURE, PARTICULARLY FOR STUDIES OF ADVERSE NEUROBEHAVIORAL CONSEQUENCES ON THE OFFSPRING. MATERNAL NICOTINE EXPOSURE HAS LONG BEEN KNOWN TO CAUSE ADVERSE NEUROBEHAVIORAL EFFECTS ON THE OFFSPRING. HOWEVER, PATERNAL TOXICANT EXPOSURE HAS ALSO BEEN FOUND TO CAUSE NEUROBEHAVIORAL TOXICITY IN THEIR OFFSPRING. RECENT WORK SUGGESTS THAT PATERNAL NICOTINE EXPOSURE CAN HAVE EPIGENETIC EFFECTS, ALTHOUGH IT REMAINS UNCLEAR WHETHER SUCH CHANGES LEAD TO NEUROBEHAVIORAL EFFECTS. IN THE CURRENT STUDY, WE INVESTIGATED THE EFFECTS OF PATERNAL NICOTINE EXPOSURE ON NEUROBEHAVIORAL DEVELOPMENT OF THEIR OFFSPRING. MALE SPRAGUE-DAWLEY RATS WERE EXPOSED TO 0 OR 2 MG/KG/DAY NICOTINE (SC) FOR 56 CONSECUTIVE DAYS WITH TWO CONSECUTIVE 2ML4 OSMOTIC MINIPUMPS. FOLLOWING TREATMENT, THESE MALES WERE MATED WITH DRUG-NAIVE FEMALE RATS. OFFSPRING OF BOTH SEXES WERE TESTED IN A BEHAVIORAL BATTERY TO ASSESS LOCOMOTION, EMOTIONAL FUNCTION AND COGNITION. PATERNAL NICOTINE EXPOSURE DID NOT IMPACT OFFSPRING VIABILITY, HEALTH OR GROWTH. HOWEVER, BEHAVIORAL FUNCTION OF THE OFFSPRING WAS SIGNIFICANTLY ALTERED BY PATERNAL NICOTINE EXPOSURE. MALE OFFSPRING WITH PATERNAL NICOTINE EXPOSURE EXHIBITED LOCOMOTOR HYPERACTIVITY IN THE FIGURE-8 APPARATUS WHEN TESTED DURING ADOLESCENCE. WHEN RETESTED IN ADULTHOOD AND REGARDLESS OF SEX, OFFSPRING OF THE NICOTINE EXPOSED FATHER SHOWED SIGNIFICANTLY REDUCED HABITUATION OF LOCOMOTOR ACTIVITY OVER THE COURSE OF THE SESSION. COMPARED TO CONTROLS, FEMALE OFFSPRING OF NICOTINE-EXPOSED FATHERS SHOWED SIGNIFICANTLY REDUCED RESPONSE LATENCY IN THE RADIAL ARM MAZE TEST. IN ADDITION TO LOCOMOTOR HYPERACTIVITY, THE OFFSPRING OF NICOTINE-EXPOSED FATHERS ALSO SHOWED SIGNIFICANTLY DIMINISHED HABITUATION IN THE NOVEL OBJECT RECOGNITION TEST. THESE RESULTS INDICATE THAT CHRONIC PATERNAL NICOTINE EXPOSURE CAN IMPACT THE BEHAVIOR OF OFFSPRING, PRODUCING LOCOMOTOR HYPERACTIVITY AND IMPAIRED HABITUATION. 2019 14 4944 31 PATERNAL PRECONCEPTION ETHANOL EXPOSURE BLUNTS HYPOTHALAMIC-PITUITARY-ADRENAL AXIS RESPONSIVITY AND STRESS-INDUCED EXCESSIVE FLUID INTAKE IN MALE MICE. A GROWING NUMBER OF ENVIRONMENTAL INSULTS HAVE BEEN SHOWN TO INDUCE EPIGENETIC EFFECTS THAT PERSIST ACROSS GENERATIONS. FOR INSTANCE, PATERNAL PRECONCEPTION EXPOSURES TO ETHANOL OR STRESS HAVE INDEPENDENTLY BEEN SHOWN TO EXERT SUCH INTERGENERATIONAL EFFECTS. SINCE ETHANOL EXPOSURE IS A PHYSIOLOGICAL STRESSOR THAT ACTIVATES THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS, WE HYPOTHESIZED THAT PATERNAL ETHANOL EXPOSURE WOULD IMPACT STRESS RESPONSIVITY OF OFFSPRING. ADULT MALE MICE WERE EXPOSED TO CHRONIC INTERMITTENT VAPOR ETHANOL OR CONTROL CONDITIONS FOR 5 WEEKS BEFORE BEING MATED WITH ETHANOL-NAIVE FEMALES TO PRODUCE ETHANOL (E)- AND CONTROL (C)-SIRED OFFSPRING. ADULT MALE AND FEMALE OFFSPRING WERE TESTED FOR PLASMA CORTICOSTERONE (CORT) LEVELS FOLLOWING ACUTE RESTRAINT STRESS AND THE MALE OFFSPRING WERE FURTHER EXAMINED FOR STRESS-EVOKED 2-BOTTLE CHOICE ETHANOL-DRINKING. PATERNAL ETHANOL EXPOSURE BLUNTED PLASMA CORT LEVELS FOLLOWING ACUTE RESTRAINT STRESS SELECTIVELY IN MALE OFFSPRING; FEMALES WERE UNAFFECTED. IN A STRESS-EVOKED ETHANOL-DRINKING ASSAY, THERE WAS NO EFFECT OF STRESS ON ETHANOL CONSUMPTION. HOWEVER, C-SIRED MALES EXHIBITED INCREASED TOTAL FLUID INTAKE (POLYDIPSIA) IN RESPONSE TO STRESS WHILE E-SIRED MALES WERE RESISTANT TO THIS STRESS-INDUCED PHENOTYPE. TAKEN TOGETHER, THESE DATA SUGGEST THAT PATERNAL ETHANOL EXPOSURE IMPARTS STRESS HYPORESPONSIVITY TO MALE OFFSPRING. 2016 15 1346 40 DETECTION OF TRANSGENERATIONAL SPERMATOGENIC INHERITANCE OF ADULT MALE ACQUIRED CNS GENE EXPRESSION CHARACTERISTICS USING A DROSOPHILA SYSTEMS MODEL. AVAILABLE INSTANCES OF INHERITANCE OF EPIGENETIC TRANSGENERATIONAL PHENOTYPE ARE LIMITED TO ENVIRONMENTAL EXPOSURES DURING EMBRYONIC AND ADULT GONADAL DEVELOPMENT. ADULT EXPOSURES CAN ALSO AFFECT GAMETOGENESIS AND THEREBY POTENTIALLY RESULT IN REPROGRAMMING OF THE GERMLINE. ALTHOUGH EXAMPLES OF EPIGENETIC EFFECTS ON GAMETOGENESIS EXIST, IT IS NOTABLE THAT TRANSGENERATIONAL INHERITANCE OF ENVIRONMENT-INDUCED ADULT PHENOTYPE HAS NOT YET BEEN REPORTED. EPIGENETIC CODES ARE CONSIDERED TO BE CRITICAL IN NEURAL PLASTICITY. A DROSOPHILA SYSTEMS MODEL OF PENTYLENETETRAZOLE (PTZ) INDUCED LONG-TERM BRAIN PLASTICITY HAS RECENTLY BEEN DESCRIBED. IN THIS MODEL, CHRONIC PTZ TREATMENT OF ADULT MALES CAUSES ALTERATIONS IN CNS TRANSCRIPTOME. HERE, WE DESCRIBE OUR SEARCH FOR TRANSGENERATIONAL SPERMATOGENIC INHERITANCE OF PTZ INDUCED GENE EXPRESSION PHENOTYPE ACQUIRED BY ADULT DROSOPHILA MALES. WE GENERATED CNS TRANSCRIPTOMIC PROFILES OF F(1) ADULTS AFTER TREATING F(0) ADULT MALES WITH PTZ AND OF F(2) ADULTS RESULTING FROM A CROSS BETWEEN F(1) MALES AND NORMAL FEMALES. SURPRISINGLY, MICROARRAY CLUSTERING SHOWED F(1) MALE PROFILE AS CLOSEST TO F(1) FEMALE AND F(0) MALE PROFILE CLOSEST TO F(2) MALE. DIFFERENTIALLY EXPRESSED GENES IN F(1) MALES, F(1) FEMALES AND F(2) MALES SHOWED SIGNIFICANT OVERLAP WITH THOSE CAUSED BY PTZ. INTERESTINGLY, MICROARRAY EVIDENCE ALSO LED TO THE IDENTIFICATION OF UPREGULATED RRNA IN F(2) MALES. NEXT, WE GENERATED MICROARRAY EXPRESSION PROFILES OF ADULT TESTIS FROM F(0) AND F(1) MALES. FURTHER SURPRISING, CLUSTERING OF CNS AND TESTIS PROFILES AND MATCHING OF DIFFERENTIALLY EXPRESSED GENES IN THEM PROVIDED EVIDENCE OF A SPERMATOGENIC MECHANISM IN THE TRANSGENERATIONAL EFFECT OBSERVED. TO OUR KNOWLEDGE, WE REPORT FOR THE FIRST TIME DETECTION OF TRANSGENERATIONAL SPERMATOGENIC INHERITANCE OF ADULT ACQUIRED SOMATIC GENE EXPRESSION CHARACTERISTIC. THE DROSOPHILA SYSTEMS MODEL OFFERS AN EXCELLENT OPPORTUNITY TO UNDERSTAND THE EPIGENETIC MECHANISMS UNDERLYING THE PHENOMENON. THE FINDING THAT ADULT ACQUIRED TRANSCRIPTOMIC ALTERATION IN SOMA IS SPERMATOGENICALLY INHERITED ACROSS GENERATIONS HAS POTENTIAL IMPLICATIONS IN HUMAN HEALTH AND EVOLUTION. 2009 16 6528 35 TRANSCRIPTIONAL CORRELATES OF CHRONIC ALCOHOL NEUROADAPTATION IN DROSOPHILA LARVAE. WHEN PRESENTED WITH THE CHOICE, DROSOPHILA MELANOGASTER FEMALES WILL OFTEN PREFER TO LAY EGGS ON FOOD CONTAINING A SIGNIFICANT AMOUNT OF ALCOHOL. WHILE, IN SOME CASES, THIS BEHAVIORAL DECISION CAN PROVIDE A SURVIVAL ADVANTAGE TO THE DEVELOPING LARVAE, IT CAN ALSO LEAD TO DEVELOPMENTAL AND COGNITIVE PROBLEMS. ALCOHOL CONSUMPTION CAN AFFECT EXECUTIVE FUNCTIONS, EPISODIC MEMORY, AND OTHER BRAIN FUNCTION CAPACITIES. HOWEVER, IN THE FRUIT FLY, THE INITIAL COGNITIVE EFFECTS OF ALCOHOL CONSUMPTION HAVE BEEN SHOWN TO REVERSE UPON PERSISTENT EXPOSURE TO ALCOHOL. USING AN OLFACTORY CONDITIONING ASSAY WHERE AN ODORANT IS IMPLEMENTED AS A CONDITIONED STIMULUS AND PAIRED WITH A HEAT SHOCK AS AN UNCONDITIONED STIMULUS, A PREVIOUS STUDY HAS SHOWN THAT WHEN EXPOSED TO A SHORT ACUTE DOSE OF ALCOHOL, DROSOPHILA LARVAE CAN NO LONGER LEARN THIS ASSOCIATION. INTERESTINGLY, UPON PROLONGED CHRONIC ALCOHOL EXPOSURE, LARVAE SEEM TO SUCCESSFULLY AVOID THE CONDITIONED STIMULUS JUST AS WELL AS CONTROL ALCOHOL-NAIVE LARVAE, SUGGESTIVE OF ALCOHOL-INDUCED NEUROADAPTATIONS. HOWEVER, THE MECHANISMS BY WHICH DROSOPHILA ADAPT TO THE PRESENCE OF ALCOHOL REMAINS UNKNOWN. IN THIS STUDY, WE EXPLORE THE TRANSCRIPTIONAL CORRELATES OF NEUROADAPTATION IN DROSOPHILA LARVAE EXPOSED TO CHRONIC ALCOHOL TO UNDERSTAND THE GENETIC AND CELLULAR COMPONENTS RESPONSIBLE FOR THIS ADAPTATION. FOR THIS, WE EMPLOYED RNA SEQUENCING TECHNOLOGY TO EVALUATE DIFFERENCES IN GENE EXPRESSION IN THE BRAIN OF LARVAE CHRONICALLY EXPOSED TO ALCOHOL. OUR RESULTS SUGGEST THAT ALCOHOL-INDUCED NEUROADAPTATIONS ARE MODULATED BY A DIVERSE ARRAY OF SYNAPTIC GENES WITHIN THE LARVAL BRAIN THROUGH A SERIES OF EPIGENETIC MODULATORS. 2021 17 1511 40 DNA METHYLATION AND POTENTIAL MULTIGENERATIONAL EPIGENETIC EFFECTS LINKED TO URANIUM CHRONIC LOW-DOSE EXPOSURE IN GONADS OF MALES AND FEMALES RATS. INTRODUCTION: AN INCREASED HEALTH PROBLEM IN INDUSTRIALISED COUNTRIES IS THE CONTEMPORARY CONCERN OF PUBLIC AND SCIENTIFIC COMMUNITY AS WELL. THIS HAS BEEN ATTRIBUTED IN PART TO ACCUMULATED ENVIRONMENTAL POLLUTANTS ESPECIALLY RADIOACTIVE SUBSTANCES AND THE USE OF NUCLEAR POWER PLANTS WORLDWIDE. HOWEVER, THE OUTCOME OF CHRONIC EXPOSURE TO LOW DOSES OF A RADIONUCLIDE SUCH AS URANIUM REMAINS UNKNOWN. RECENTLY, A PARADIGM SHIFT IN THE PERCEPTION OF RISK OF RADIOTOXICOLOGY HAS EMERGED THROUGH INVESTIGATING THE POSSIBILITY OF TRANSMISSION OF BIOLOGICAL EFFECTS OVER GENERATIONS, IN PARTICULAR BY EPIGENETIC PATHWAYS. THESE PROCESSES ARE KNOWN FOR THEIR CRUCIAL ROLES ASSOCIATED WITH THE DEVELOPMENT OF SEVERAL DISEASES. OBJECTIVE: THE CURRENT WORK INVESTIGATES THE EPIGENETIC EFFECT OF CHRONIC EXPOSURE TO LOW DOSES OF URANIUM AND ITS INHERITANCE ACROSS GENERATIONS. MATERIALS AND METHODS TO TEST THIS PROPOSITION, A RODENT MULTIGENERATIONAL MODEL, MALES AND FEMALES, WERE EXPOSED TO A NON-TOXIC CONCENTRATION OF URANIUM (40MGL(-1) DRINKING WATER) FOR NINE MONTHS. THE URANIUM EFFECTS ON WERE EVALUATED OVER THREE GENERATIONS (F0, F1 AND F2) BY ANALYSING THE DNA METHYLATION PROFILE AND DNMT GENES EXPRESSION IN OVARIES AND TESTES TISSUES. RESULTS: HERE WE REPORT A SIGNIFICANT HYPERMETHYLATION OF TESTES DNA (P <0.005) WHEREAS OVARIES SHOWED HYPOMETHYLATED DNA (P <0.005). INTERESTINGLY, THIS DNA METHYLATION PROFILE WAS SIGNIFICANTLY MAINTAINED ACROSS GENERATIONS F0, F1 AND F2. FURTHERMORE, QPCR RESULTS OF BOTH TISSUES IMPLY A SIGNIFICANT CHANGE IN THE EXPRESSION OF DNA METHYLTRANSFERASE GENES (DNMT 1 AND DNMT3A/B) AS WELL. CONCLUSION: ALTOGETHER, OUR WORK DEMONSTRATES FOR THE FIRST TIME A SEX-DEPENDANCE AND INHERITANCE OF EPIGENETIC MARKS, DNA METHYLATION, AS A BIOLOGICAL RESPONSE TO THE EXPOSURE TO LOW DOSES OF URANIUM. HOWEVER, IT IS NOT CLEAR WHICH TYPE OF REPRODUCTIVE CELL TYPE IS MORE RESPONSIVE IN THIS CONTEXT. 2018 18 4077 31 MATERNAL INFLAMMATION INDUCES SPATIAL LEARNING AND MEMORY IMPAIRMENT IN THE F1 AND F2 GENERATIONS OF MICE VIA SEX-SPECIFIC EPIGENETIC MECHANISMS. MOUNTING EVIDENCE INDICATES THAT HISTONE MODIFICATIONS ARE INVOLVED IN AGING-ASSOCIATED COGNITIVE DECLINE (AACD) AND CAN BE TRANSMITTED TO OFFSPRING OVER MULTIPLE GENERATIONS UNDER CONDITIONS OF STRESS. HERE, WE INVESTIGATED THE EFFECTS OF MATERNAL SUB-CHRONIC INFLAMMATION CAUSED BY LIPOPOLYSACCHARIDE (LPS) ON AACD AND HISTONE MODIFICATIONS IN THE F1 AND F2 GENERATIONS OF EXPERIMENTAL MICE AS WELL AS THE POTENTIAL SEX SPECIFICITY OF INTERGENERATIONAL EFFECTS. IN BRIEF, F0-GENERATION CD-1 DAMS WERE EXPOSED TO LPS (50 MICROG/KG) OR SALINE (CON) DURING LATE PREGNANCY. SUBSEQUENTLY, F1 MALES AND FEMALES (AT 2 MONTHS-OF-AGE) FROM THE LPS TREATMENT GROUP WERE MATED WITH NON-LITTERMATES FROM THE LPS GROUP OR WILD-TYPE MICE TO PRODUCE F2 GENERATIONS OF PARENTAL- (F2-LPS(2)), PATERNAL- (F2M-LPS(1)) AND MATERNAL-ORIGIN (F2F-LPS(1)) MICE. THEN, CON-F1 MALES AND FEMALES WERE MATED WITH WILD-TYPE MICE TO GENERATE F2 GENERATIONS OF PATERNAL- (F2M-CON(1)) AND MATERNAL-ORIGIN (F2F-CON(1)). NEXT, WE EVALUATED THE COGNITIVE ABILITY AND LEVELS OF HIPPOCAMPAL H4K12AC AND H3K9ME3 IN THE F1 AND F2 OFFSPRING AT 3- AND 13 MONTHS-OF-AGE. OVERALL, F1 MALE AND FEMALE LPS GROUPS PRESENTED WITH ELEVATED CORTICOSTERONE (P < 0.001, P = 0.036, P = 0.025, 0.012, RESPECTIVELY) AND CYTOKINE RESPONSES, POORER COGNITIVE PERFORMANCE (ALL P < 0.05) AND H3K9 HYPERMETHYLATION AND H4K12 HYPOACETYLATION IN THE DORSAL HIPPOCAMPUS (ALL P < 0.05); THESE ISSUES WERE CARRIED OVER TO THE F2 GENERATION VIA THE PARENTS, PREDOMINANTLY IN THE PATERNAL LINEAGE. MOREOVER, THE LEVELS OF H3K9ME3 AND H4K12AC WERE SIGNIFICANT CORRELATED WITH COGNITIVE PERFORMANCE (ALL P < 0.05), REGARDLESS OF WHETHER INFLAMMATORY INSULTS HAD BEEN INCURRED DIRECTLY OR INDIRECTLY. THESE FINDINGS INDICATED THAT GESTATIONAL INFLAMMATORY INSULTS IN THE F0 GENERATION ACCELERATED AACD IN THE F2 GENERATION, ALONG WITH H3K9 HYPERMETHYLATION AND H4K12 HYPOACETYLATION IN THE HIPPOCAMPUS, AND THAT THESE ISSUES WERE DERIVED FROM THE F1 PARENTS, ESPECIALLY FROM THE F1 FATHERS. 2022 19 899 25 CHRONIC EXPOSURE TO A LOW CONCENTRATION OF BISPHENOL A DURING FOLLICLE CULTURE AFFECTS THE EPIGENETIC STATUS OF GERMINAL VESICLES AND METAPHASE II OOCYTES. OBJECTIVE: TO DETERMINE WHETHER EXPOSURE TO LOW CONCENTRATIONS OF THE ENDOCRINE DISRUPTING CHEMICAL BISPHENOL A (BPA) DURING FOLLICLE CULTURE AND OOCYTE GROWTH ALTERS THE METHYLATION STATUS OF DIFFERENTIALLY METHYLATED REGIONS (DMRS) OF IMPRINTED GENES AND HISTONE POSTTRANSLATIONAL MODIFICATION PATTERNS IN MAMMALIAN OOCYTES. DESIGN: COMPARATIVE AND CONTROL STUDY. SETTING: EXPERIMENTAL LABORATORY. ANIMAL(S): C57/BL6JXCBA/CA MICE. INTERVENTION(S): EXPOSURE OF OOCYTES TO 3 NM OR 300 NM BPA DURING FOLLICLE CULTURE FROM PREANTRAL TO ANTRAL STAGE. MAIN OUTCOME MEASURE(S): METHYLATION STATUS OF DMRS OF MATERNALLY IMPRINTED (SNRPN, IGF2R, AND MEST) AND PATERNALLY IMPRINTED GENE(S) (H19) IN MOUSE GERMINAL VESICLE OOCYTES; TRIMETHYLATION OF HISTONE H3K9, ACETYLATION OF HISTONE H4K12, AND DISTANCE BETWEEN CENTROMERES OF SISTER CHROMATIDS IN METAPHASE II OOCYTES. RESULT(S): EXPOSURE TO 3 NM BPA WAS ASSOCIATED WITH SLIGHTLY ACCELERATED FOLLICLE DEVELOPMENT, STATISTICALLY SIGNIFICANT INCREASES IN ALLELE METHYLATION ERRORS IN DMRS OF MATERNALLY IMPRINTED GENES, AND STATISTICALLY SIGNIFICANT DECREASES IN HISTONE H3K9 TRIMETHYLATION AND INTERKINETOCHORE DISTANCE. CONCLUSION(S): THE DISTURBANCES IN OOCYTE GENOMIC IMPRINTING AND MODIFICATION OF POSTTRANSLATIONAL HISTONE AND CENTROMERE ARCHITECTURE PROVIDE THE FIRST LINK BETWEEN LOW BPA EXPOSURES AND INDUCTION OF EPIGENETIC CHANGES THAT MAY CONTRIBUTE TO CHROMOSOME CONGRESSION FAILURES AND MEIOTIC ERRORS, AND TO ALTERED GENE EXPRESSION THAT MIGHT AFFECT HEALTH OF THE OFFSPRING. 2013 20 5200 29 PRENATAL MATERNAL STRESS PREDICTS METHYLATION OF GENES REGULATING THE HYPOTHALAMIC-PITUITARY-ADRENOCORTICAL SYSTEM IN MOTHERS AND NEWBORNS IN THE DEMOCRATIC REPUBLIC OF CONGO. EXPOSURE TO STRESS EARLY IN LIFE PERMANENTLY SHAPES ACTIVITY OF THE HYPOTHALAMIC-PITUITARY-ADRENOCORTICAL (HPA) AXIS AND THE BRAIN. PRENATALLY, GLUCOCORTICOIDS PASS THROUGH THE PLACENTA TO THE FETUS WITH POSTNATAL IMPACTS ON BRAIN DEVELOPMENT, BIRTH WEIGHT (BW), AND HPA AXIS FUNCTIONING. LITTLE IS KNOWN ABOUT THE BIOLOGICAL MECHANISMS BY WHICH PRENATAL STRESS AFFECTS POSTNATAL FUNCTIONING. THIS STUDY ADDRESSES THIS GAP BY EXAMINING THE EFFECT OF CHRONIC STRESS AND TRAUMATIC WAR-RELATED STRESS ON EPIGENETIC CHANGES IN FOUR KEY GENES REGULATING THE HPA AXIS IN NEONATAL CORD BLOOD, PLACENTA, AND MATERNAL BLOOD: CRH, CRHBP, NR3C1, AND FKBP5. PARTICIPANTS WERE 24 MOTHER-NEWBORN DYADS IN THE CONFLICT-RIDDEN REGION OF THE EASTERN DEMOCRATIC REPUBLIC OF CONGO. BW DATA WERE COLLECTED AT DELIVERY AND MATERNAL INTERVIEWS WERE CONDUCTED TO ASSESS CULTURALLY RELEVANT CHRONIC AND WAR-RELATED STRESSORS. CHRONIC STRESS AND WAR TRAUMA HAD WIDESPREAD EFFECTS ON HPA AXIS GENE METHYLATION, WITH SIGNIFICANT EFFECTS OBSERVED AT TRANSCRIPTION FACTOR BINDING (TFB) SITES IN ALL TARGET GENES TESTED. SOME CHANGES IN METHYLATION WERE UNIQUE TO CHRONIC OR WAR STRESS, WHEREAS OTHERS WERE OBSERVED ACROSS BOTH STRESSOR TYPES. MOREOVER, STRESS EXPOSURES IMPACTED MATERNAL AND FETAL TISSUES DIFFERENTLY, SUPPORTING THEORETICAL MODELS THAT STRESS IMPACTS VARY ACCORDING TO LIFE PHASE. METHYLATION IN SEVERAL NR3C1 AND CRH CPG SITES, ALL LOCATED AT TFB SITES, WAS ASSOCIATED WITH BW. THESE FINDINGS SUGGEST THAT PRENATAL STRESS EXPOSURE IMPACTS DEVELOPMENT VIA EPIGENETIC CHANGES IN HPA AXIS GENES. 2016