1 2647 140 EPIGENOMIC PLASTICITY OF ARABIDOPSIS MSH1 MUTANTS UNDER PROLONGED COLD STRESS. DYNAMIC TRANSCRIPTIONAL AND EPIGENETIC CHANGES ENABLE RAPID ADAPTIVE BENEFIT TO ENVIRONMENTAL FLUCTUATIONS. HOWEVER, THE UNDERLYING MECHANISMS AND THE EXTENT TO WHICH THIS OCCURS ARE NOT WELL KNOWN. MUTS HOMOLOG 1 (MSH1) MUTANTS CAUSE HERITABLE DEVELOPMENTAL PHENOTYPES ACCOMPANIED BY MODULATION OF DEFENSE, PHYTOHORMONE, STRESS-RESPONSE, AND CIRCADIAN RHYTHM GENES, AS WELL AS HERITABLE CHANGES IN DNA METHYLATION PATTERNS. CONSISTENT WITH GENE EXPRESSION CHANGES, MSH1 MUTANTS DISPLAY ENHANCED TOLERANCE FOR ABIOTIC STRESS INCLUDING DROUGHT AND SALT STRESS, WHILE SHOWING INCREASED SUSCEPTIBILITY TO FREEZING TEMPERATURES. DESPITE CHANGES IN DEFENSE AND BIOTIC STRESS-RESPONSE GENES, MSH1 MUTANTS SHOWED INCREASING SUSCEPTIBILITY TO THE BACTERIAL PATHOGEN PSEUDOMONAS SYRINGAE. OUR RESULTS SUGGEST THAT CHRONIC COLD AND LOW LIGHT STRESS (10 DEGREES C, 150 MUMOL M(-2) S(-1)) INFLUENCES NON-CG METHYLATION TO A GREATER DEGREE IN MSH1 MUTANTS COMPARED TO WILD-TYPE COL-0. FURTHERMORE, CHG CHANGES ARE MORE CLOSELY PERICENTROMERIC, WHEREAS CHH CHANGES ARE GENERALLY MORE DISPERSED. THIS INCREASED VARIATION IN NON-CG METHYLATION PATTERN DOES NOT SIGNIFICANTLY AFFECT THE MSH1-DERIVED ENHANCED GROWTH BEHAVIOR AFTER MUTANTS ARE CROSSED WITH ISOGENIC WILD TYPE, REITERATING THE IMPORTANCE OF CG METHYLATION CHANGES IN MSH1-DERIVED ENHANCED VIGOR. THESE RESULTS INDICATE THAT MSH1METHYLOME IS HYPER-RESPONSIVE TO ENVIRONMENTAL STRESS IN A MANNER DISTINCT FROM THE WILD-TYPE RESPONSE, BUT CG METHYLATION CHANGES ARE POTENTIALLY RESPONSIBLE FOR GROWTH VIGOR CHANGES IN THE CROSSED PROGENY. 2018 2 1534 34 DNA METHYLATION DYNAMICS IN A COASTAL FOUNDATION SEAGRASS SPECIES UNDER ABIOTIC STRESSORS. DNA METHYLATION (DNAM) HAS BEEN INTENSIVELY STUDIED IN TERRESTRIAL PLANTS IN RESPONSE TO ENVIRONMENTAL CHANGES, BUT ITS DYNAMIC CHANGES IN A TEMPORAL SCALE REMAIN UNEXPLORED IN MARINE PLANTS. THE SEAGRASS POSIDONIA OCEANICA RANKS AMONG THE SLOWEST-GROWING AND LONGEST-LIVING PLANTS ON EARTH, AND IS PARTICULARLY VULNERABLE TO SEA WARMING AND LOCAL ANTHROPOGENIC PRESSURES. HERE, WE ANALYSED THE DYNAMICS OF DNAM CHANGES IN PLANTS COLLECTED FROM COASTAL AREAS DIFFERENTIALLY IMPACTED BY EUTROPHICATION (I.E. OLIGOTROPHIC, OL; EUTROPHIC, EU) AND EXPOSED TO ABIOTIC STRESSORS (NUTRIENTS, TEMPERATURE INCREASE AND THEIR COMBINATION). LEVELS OF GLOBAL DNAM (% 5-MC) AND THE EXPRESSION OF KEY GENES INVOLVED IN DNAM WERE ASSESSED AFTER ONE, TWO AND FIVE WEEKS OF EXPOSURE. RESULTS REVEALED A CLEAR DIFFERENTIATION BETWEEN PLANTS, DEPENDING ON ENVIRONMENTAL STIMULI, TIME OF EXPOSURE AND PLANTS' ORIGIN. % 5-MC LEVELS WERE HIGHER DURING THE INITIAL STRESS EXPOSURE ESPECIALLY IN OL PLANTS, WHICH UPREGULATED ALMOST ALL GENES INVOLVED IN DNAM. CONTRARILY, EU PLANTS SHOWED LOWER EXPRESSION LEVELS, WHICH INCREASED UNDER CHRONIC EXPOSURE TO STRESSORS, PARTICULARLY TO TEMPERATURE. THESE FINDINGS SHOW THAT DNAM IS DYNAMIC IN P. OCEANICA DURING STRESS EXPOSURE AND UNDERLINED THAT ENVIRONMENTAL EPIGENETIC VARIATIONS COULD BE IMPLICATED IN THE REGULATION OF ACCLIMATION AND PHENOTYPIC DIFFERENCES DEPENDING ON LOCAL CONDITIONS. 2023 3 4592 29 NATURAL ENVIRONMENTS, NATURE RELATEDNESS AND THE ECOLOGICAL THEATER: CONNECTING SATELLITES AND SEQUENCING TO SHINRIN-YOKU. RECENT ADVANCES IN RESEARCH CONCERNING THE PUBLIC HEALTH VALUE OF NATURAL ENVIRONMENTS HAVE BEEN REMARKABLE. THE GROWING INTEREST IN THIS TOPIC (OFTEN HOUSED UNDER TERMS SUCH AS GREEN AND/OR BLUE SPACE) HAS BEEN OCCURRING IN PARALLEL WITH THE MICROBIOME REVOLUTION AND AN INCREASED USE OF REMOTE SENSING TECHNOLOGY IN PUBLIC HEALTH. IN THE CONTEXT OF BIODIVERSITY LOSS, RAPID URBANIZATION, AND ALARMING RATES OF GLOBAL NON-COMMUNICABLE DISEASES (MANY ASSOCIATED WITH CHRONIC, LOW-GRADE INFLAMMATION), DISCUSSIONS OF NATURAL VIS-A-VIS BUILT ENVIRONMENTS ARE NOT MERELY FODDER FOR INTELLECTUAL CURIOSITY. HERE, WE ARGUE FOR INCREASED INTERDISCIPLINARY COLLABORATION WITH THE AIM OF BETTER UNDERSTANDING THE MECHANISMS-INCLUDING AEROBIOLOGICAL AND EPIGENETIC-THAT MIGHT HELP EXPLAIN SOME OF THE NOTED POSITIVE HEALTH OUTCOMES. IT IS OUR CONTENTION THAT SOME OF THESE MECHANISMS ARE RELATED TO ECODIVERSITY (I.E., THE SUM OF BIODIVERSITY AND GEODIVERSITY, INCLUDING BIOTIC AND ABIOTIC CONSTITUENTS). WE ALSO ENCOURAGE RESEARCHERS TO MORE CLOSELY EXAMINE INDIVIDUAL NATURE RELATEDNESS AND HOW IT MIGHT INFLUENCE MANY OUTCOMES THAT ARE AT THE INTERFACE OF LIFESTYLE HABITS AND CONTACT WITH ECODIVERSITY. 2016 4 3279 34 HERITABLE ALTERATION IN DNA METHYLATION INDUCED BY NITROGEN-DEFICIENCY STRESS ACCOMPANIES ENHANCED TOLERANCE BY PROGENIES TO THE STRESS IN RICE (ORYZA SATIVA L.). CYTOSINE METHYLATION IS RESPONSIVE TO VARIOUS BIOTIC- AND ABIOTIC-STRESSES, WHICH MAY PRODUCE HERITABLE EPIALLELES. NITROGEN (N)-DEFICIENCY IS AN ABIOTIC STRESS BEING REPEATEDLY EXPERIENCED BY PLANTS. TO ADDRESS POSSIBLE EPIGENETIC CONSEQUENCES OF N-DEFICIENCY-STRESS, WE INVESTIGATED THE STABILITY OF CYTOSINE METHYLATION IN RICE (ORYZA SATIVA L.) SUBSEQUENT TO A CHRONIC (A WHOLE-GENERATION) N-DEFICIENCY AT TWO LEVELS, MODERATE (20MG/L) AND SEVERE (10MG/L), UNDER HYDROPONIC CULTURE. MSAP ANALYSIS REVEALED THAT LOCUS-SPECIFIC METHYLATION ALTERATION OCCURRED IN LEAF-TISSUE OF THE STRESSED PLANTS (S(0)) EXPERIENCING EITHER LEVEL OF N-DEFICIENCY, WHICH WAS VALIDATED BY GEL-BLOTTING. ANALYSIS ON THREE NON-STRESSED SELF-FED PROGENIES (S(1), S(2) AND S(3)) BY GEL-BLOTTING INDICATED THAT CA. 50% OF THE ALTERED METHYLATION PATTERNS IN SOMATIC CELLS (LEAF) OF THE STRESSED S(0) PLANTS WERE RECAPTURED IN S(1), WHICH WERE THEN STABLY INHERITED TO S(2) AND S(3). BISULFITE SEQUENCING OF TWO VARIANT MSAP LOCI WITH HOMOLOGY TO LOW-COPY RETROTRANSPOSONS ON ONE STRESSED PLANT (S(0)) AND ITS NON-STRESSED PROGENIES (S(1) AND S(2)) SHOWED THAT WHEREAS ONE LOCUS EXHIBITED LIMITED AND NON-HERITABLE CHH METHYLATION ALTERATION, THE OTHER LOCUS MANIFESTED DRAMATIC HERITABLE HYPERMETHYLATION AT NEARLY ALL CYTOSINE SITES WITHIN THE ASSAYED REGION. INTRIGUINGLY, WHEN TWO GROUPS OF S(2) PLANTS DESCENDED FROM THE SAME N-DEFICIENCY-STRESSED S(0) PLANT WERE RE-SUBJECTED TO THE STRESS, THE GROUP INHERITING THE MODIFIED METHYLATION PATTERNS SHOWED ENHANCED TOLERANCE TO THE N-DEFICIENCY-STRESS COMPARED WITH THE GROUP BEARING THE ORIGINAL PATTERNS. OUR RESULTS THUS DEMONSTRATE HERITABILITY OF AN ACQUIRED ADAPTIVE TRAIT IN RICE, WHICH WAS ACCOMPANIED BY EPIGENETIC INHERITANCE OF MODIFIED CYTOSINE METHYLATION PATTERNS, IMPLICATING AN EPIGENETIC BASIS UNDERLYING THE INHERITANCE OF AN ACQUIRED TRAIT IN PLANTS. 2011 5 2296 23 EPIGENETIC REGULATION OF ABIOTIC STRESS MEMORY: MAINTAINING THE GOOD THINGS WHILE THEY LAST. AS SESSILE ORGANISMS, PLANTS HAVE EVOLVED SOPHISTICATED WAYS TO CONSTANTLY GAUGE AND ADAPT TO CHANGING ENVIRONMENTAL CONDITIONS INCLUDING EXTREMES THAT MAY BE HARMFUL TO THEIR GROWTH AND DEVELOPMENT AND ARE THUS PERCEIVED AS STRESS. IN NATURE, STRESSFUL EVENTS ARE OFTEN CHRONIC OR RECURRING AND THUS AN INITIAL STRESS MAY PRIME A PLANT TO RESPOND MORE EFFICIENTLY TO A SUBSEQUENT STRESS EVENT. AN EPIGENETIC BASIS OF SUCH STRESS MEMORY WAS LONG POSTULATED AND IN RECENT YEARS IT HAS BEEN SHOWN THAT THIS IS INDEED THE CASE. HIGH TEMPERATURE STRESS HAS PROVEN AN EXCELLENT SYSTEM TO UNPICK THE MOLECULAR BASIS OF SOMATIC STRESS MEMORY, WHICH INCLUDES HISTONE MODIFICATIONS AND NUCLEOSOME OCCUPANCY. THIS REVIEW DISCUSSES RECENT FINDINGS AND PINPOINTS OPEN QUESTIONS IN THE FIELD. 2021 6 5698 43 SIMULATED CLIMATE WARMING AND MITOCHONDRIAL HAPLOGROUP MODULATE TESTICULAR SMALL NON-CODING RNA EXPRESSION IN THE NEOTROPICAL PSEUDOSCORPION, CORDYLOCHERNES SCORPIOIDES. RECENT THEORY SUGGESTS THAT TROPICAL TERRESTRIAL ARTHROPODS ARE AT SIGNIFICANT RISK FROM CLIMATE WARMING. METABOLIC RATE IN SUCH ECTOTHERMIC SPECIES INCREASES EXPONENTIALLY WITH ENVIRONMENTAL TEMPERATURE, AND A SMALL TEMPERATURE INCREASE IN A HOT ENVIRONMENT CAN THEREFORE HAVE A GREATER PHYSIOLOGICAL IMPACT THAN A LARGE TEMPERATURE INCREASE IN A COOL ENVIRONMENT. IN TWO RECENT STUDIES OF THE NEOTROPICAL PSEUDOSCORPION, CORDYLOCHERNES SCORPIOIDES, SIMULATED CLIMATE WARMING SIGNIFICANTLY DECREASED SURVIVAL, BODY SIZE AND LEVEL OF SEXUAL DIMORPHISM. HOWEVER, THESE EFFECTS WERE MINOR COMPARED WITH CATASTROPHIC CONSEQUENCES FOR MALE FERTILITY AND FEMALE FECUNDITY, IDENTIFYING REPRODUCTION AS THE LIFE STAGE MOST VULNERABLE TO CLIMATE WARMING. HERE, WE EXAMINE THE EFFECTS OF CHRONIC HIGH-TEMPERATURE EXPOSURE ON EPIGENETIC REGULATION IN C. SCORPIOIDES IN THE CONTEXT OF NATURALLY OCCURRING VARIATION IN MITOCHONDRIAL DNA. EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND SMALL NON-CODING RNA (SNCRNA) EXPRESSION, ARE PARTICULARLY SENSITIVE TO ENVIRONMENTAL FACTORS SUCH AS TEMPERATURE, WHICH CAN INDUCE CHANGES IN EPIGENETIC STATES AND PHENOTYPES THAT MAY BE HERITABLE ACROSS GENERATIONS. OUR RESULTS INDICATE THAT EXPOSURE OF MALE PSEUDOSCORPIONS TO ELEVATED TEMPERATURE SIGNIFICANTLY ALTERED THE EXPRESSION OF >60 SNCRNAS IN TESTICULAR TISSUE, SPECIFICALLY MICRORNAS AND PIWI-INTERACTING RNAS. MITOCHONDRIAL HAPLOGROUP WAS ALSO A SIGNIFICANT FACTOR INFLUENCING BOTH SNCRNAS AND MITOCHONDRIAL GENE EXPRESSION. THESE FINDINGS DEMONSTRATE THAT CHRONIC HEAT STRESS CAUSES CHANGES IN EPIGENETIC PROFILES THAT MAY ACCOUNT FOR REPRODUCTIVE DYSFUNCTION IN C. SCORPIOIDES MALES. MOREOVER, THROUGH ITS EFFECTS ON EPIGENETIC REGULATION, MITOCHONDRIAL DNA POLYMORPHISM MAY PROVIDE THE POTENTIAL FOR AN ADAPTIVE EVOLUTIONARY RESPONSE TO CLIMATE WARMING. 2018 7 4923 27 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 8 184 31 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 9 2698 33 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 10 4009 33 LOW LEVELS OF CD INDUCE PERSISTING EPIGENETIC MODIFICATIONS AND ACCLIMATION MECHANISMS IN THE EARTHWORM LUMBRICUS TERRESTRIS. TOXIC EFFECTS OF CADMIUM (CD), A COMMON SOIL POLLUTANT, ARE STILL NOT VERY WELL UNDERSTOOD, PARTICULARLY IN REGARD TO ITS EPIGENETIC IMPACT. THEREFORE, THE AIM OF THIS STUDY WAS TO ASSESS DNA METHYLATION CHANGES AND THEIR PERSISTENCE IN THE EARTHWORM LUMBRICUS TERRESTRIS UPON CHRONIC LOW DOSE CD EXPOSURE USING METHYLATION SENSITIVE AMPLIFICATION POLYMORPHISM (MSAP). MOREOVER, THE BIOMARKER RESPONSE AND FITNESS OF THE EARTHWORMS, AS WELL AS THE EXPRESSION OF DETOXIFICATION-RELATED GENES (METALLOTHIONEIN (MT) AND PHYTOCHELATIN SYNTHASE (PCS)) WAS EVALUATED. LOW LEVELS OF CD CAUSED AN INCREASE IN GENOME-WIDE DNA METHYLATION, WHICH REMAINED PARTLY MODIFIED, EVEN AFTER SEVERAL MONTHS OF RECOVERY IN UNPOLLUTED SOIL. INCREASED CELLULAR STRESS SEEMED TO DECREASE AFTER TWO WEEKS OF EXPOSURE WHEREAS FITNESS PARAMETERS REMAINED UNAFFECTED BY CD, PROBABLY AS A RESULT FROM THE ACTIVATION OF DETOXIFICATION MECHANISMS LIKE THE EXPRESSION OF MTS. INTERESTINGLY, EVEN THOUGH THE LEVEL OF CD EXPOSURE WAS VERY LOW, MT EXPRESSION LEVELS INDICATE THE DEVELOPMENT OF ACCLIMATION MECHANISMS. TAKEN TOGETHER, THIS STUDY DEMONSTRATES THAT ACCLIMATION, AS WELL AS EPIGENETIC MODIFICATIONS CAN OCCUR ALREADY IN MODERATELY POLLUTED ENVIRONMENTS. IN ADDITION, THESE EFFECTS CAN HAVE LONG-LASTING IMPACTS ON KEY SPECIES OF SOIL INVERTEBRATES AND MIGHT PERSIST LONG AFTER THE ACTUAL HEAVY METAL CHALLENGE HAS PASSED. 2017 11 3301 22 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 12 5344 28 RADIOBIOLOGICAL FEATURES IN OFFSPRING OF NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER AFTER CHERNOBYL ACCIDENT. IN THEIR NATURAL HABITATS, POPULATIONS OF ORGANISMS ARE FACED WITH DIFFERENT LEVELS OF CHRONIC LOW-INTENSITY RADIATION, CAUSING A WIDE RANGE OF RADIOBIOLOGICAL EFFECTS (FROM RADIOSENSITIVITY TO RADIOADAPTIVE RESPONSE AND HORMESIS). IN THIS STUDY, SPECIMENS OF DROSOPHILA MELANOGASTER WERE SELECTED FROM TERRITORIES OF THE CHERNOBYL NUCLEAR POWER PLANT WITH DIFFERENT LEVELS OF RADIOACTIVE CONTAMINATION. THE ISOGENIC STOCKS DERIVED FROM THESE SPECIMENS REPRESENT THE GENETIC SYSTEMS OF CURRENT POPULATIONS AND MAKE IT POSSIBLE TO STUDY RADIORESISTANCE AND ITS MECHANISMS IN FUTURE GENERATIONS UNDER CONTROLLED LABORATORY CONDITIONS. PREVIOUS STUDIES HAVE SHOWN THAT TRANSGENERATIONAL RADIATION EFFECTS AT THE LEVEL OF LETHAL MUTATIONS AND SURVIVAL RATE ARE UNSTABLE AND DEPEND NOT ONLY ON THE LEVEL OF CHRONIC LOW-INTENSITY IRRADIATION, BUT ALSO ON OTHER FACTORS. A SINGLE ACUTE IRRADIATION EXPOSURE OF OFFSPRING WHOSE PARENTS INHABITED A SITE WITH A HIGHER LEVEL OF CHRONIC IRRADIATION MADE IT POSSIBLE TO REVEAL PRONOUNCED RADIORESISTANT FEATURES IN THE OFFSPRING. AND THE OFFSPRING WHOSE PARENTS WERE EXPOSED TO RADIATION LEVELS CLOSE TO THE NATURAL RADIATION BACKGROUND, ON THE CONTRARY, ACQUIRED RADIOSENSITIVE FEATURES. THEIR RESPONSE TO ACUTE EXPOSURE INCLUDES A HIGH-FREQUENCY OF LETHAL MUTATIONS AND A SHORT LIFESPAN. THE DIFFERENTIAL RESPONSE TO DIFFERENT LEVELS OF CHRONIC PARENTAL EXPOSURE IS CAUSED BY DIFFERENCES IN THE ACTIVITIES OF CERTAIN TRANSPOSONS THAT DESTABILIZE THE GENOME. OUR DATA CONTRIBUTE TO THE UNDERSTANDING OF GENETIC AND EPIGENETIC MECHANISMS (VIA TRANSPOSON ACTIVITY) OF THE EFFECT OF PARENTAL RADIATION EXPOSURE ON THE HEALTH AND ADAPTIVE POTENTIAL OF POPULATIONS AFFECTED BY THE TECHNOGENICALLY INCREASED RADIATION BACKGROUND. 2022 13 4593 32 NATURAL GENETIC VARIATION IN A MULTIGENERATIONAL PHENOTYPE IN C. ELEGANS. ALTHOUGH HEREDITY MOSTLY RELIES ON THE TRANSMISSION OF DNA SEQUENCE, ADDITIONAL MOLECULAR AND CELLULAR FEATURES ARE HERITABLE ACROSS SEVERAL GENERATIONS. IN THE NEMATODE CAENORHABDITIS ELEGANS, INSIGHTS INTO SUCH UNCONVENTIONAL INHERITANCE RESULT FROM TWO LINES OF WORK. FIRST, THE MORTAL GERMLINE (MRT) PHENOTYPE WAS DEFINED AS A MULTIGENERATIONAL PHENOTYPE WHEREBY A SELFING LINEAGE BECOMES STERILE AFTER SEVERAL GENERATIONS, IMPLYING MULTIGENERATIONAL MEMORY [1, 2]. SECOND, CERTAIN RNAI EFFECTS ARE HERITABLE OVER SEVERAL GENERATIONS IN THE ABSENCE OF THE INITIAL TRIGGER [3-5]. BOTH LINES OF WORK CONVERGED WHEN THE SUBSET OF MRT MUTANTS THAT ARE HEAT SENSITIVE WERE FOUND TO CLOSELY CORRESPOND TO MUTANTS DEFECTIVE IN THE RNAI-INHERITANCE MACHINERY, INCLUDING HISTONE MODIFIERS [6-9]. HERE, WE REPORT THE SURPRISING FINDING THAT SEVERAL C. ELEGANS WILD ISOLATES DISPLAY A HEAT-SENSITIVE MORTAL GERMLINE PHENOTYPE IN LABORATORY CONDITIONS: UPON CHRONIC EXPOSURE TO HIGHER TEMPERATURES, SUCH AS 25 DEGREES C, LINES REPRODUCIBLY BECOME STERILE AFTER SEVERAL GENERATIONS. THIS PHENOMENON IS REVERSIBLE, AS IT CAN BE SUPPRESSED BY TEMPERATURE ALTERNATIONS AT EACH GENERATION, SUGGESTING A NON-GENETIC BASIS FOR THE STERILITY. WE TESTED WHETHER NATURAL VARIATION IN THE TEMPERATURE-INDUCED MRT PHENOTYPE WAS OF GENETIC NATURE BY BUILDING RECOMBINANT INBRED LINES BETWEEN THE ISOLATES MY10 (MRT) AND JU1395 (NON-MRT). USING BULK SEGREGANT ANALYSIS, WE DETECTED TWO QUANTITATIVE TRAIT LOCI. AFTER FURTHER RECOMBINANT MAPPING AND GENOME EDITING, WE IDENTIFIED THE MAJOR CAUSAL LOCUS AS A POLYMORPHISM IN THE SET-24 GENE, ENCODING A SET- AND SPK-DOMAIN PROTEIN. WE CONCLUDE THAT C. ELEGANS NATURAL POPULATIONS MAY HARBOR NATURAL GENETIC VARIATION IN EPIGENETIC INHERITANCE PHENOMENA. 2018 14 3109 29 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 15 6552 29 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 16 4932 29 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 17 3474 38 IDENTIFICATION OF A RICE METALLOCHAPERONE FOR CADMIUM TOLERANCE BY AN EPIGENETIC MECHANISM AND POTENTIAL USE FOR CLEAN UP IN WETLAND. CADMIUM (CD) IS A TOXIC HEAVY METAL THAT INITIATES DIVERSE CHRONIC DISEASES THROUGH FOOD CHAINS. DEVELOPING A BIOTECHNOLOGY FOR MANIPULATING CD UPTAKE IN PLANTS IS BENEFICIAL TO REDUCE ENVIRONMENTAL AND HEALTH RISKS. HERE, WE IDENTIFIED A NOVEL EPIGENETIC MECHANISM UNDERLYING CD ACCUMULATION REGULATED BY AN UNCHARACTERIZED METALLOCHAPERONE NAMELY HEAVY METAL RESPONSIVE PROTEIN (HMP) IN RICE PLANTS. OSHMP RESIDES IN CYTOPLASM AND NUCLEUS, DOMINANTLY INDUCED BY CD STRESS AND BINDS DIRECTLY TO CD IONS. OSHMP OVEREXPRESSION ENHANCED THE RICE GROWTH UNDER CD STRESS BUT ACCUMULATED MORE CD, WHEREAS KNOCKOUT OR KNOCKDOWN OF OSHMP SHOWED A CONTRASTING EFFECT. THE ENHANCED CD ACCUMULATION IN THE TRANSGENIC LINES WAS CONFIRMED BY A LONG-TERM EXPERIMENT WITH RICE GROWING AT THE ENVIRONMENTALLY REALISTIC CD CONCENTRATION IN SOIL. THE BISULFITE SEQUENCING AND CHROMATIN IMMUNOPRECIPITATION ASSESSMENTS REVEALED THAT CD STRESS REDUCED SIGNIFICANTLY THE DNA METHYLATION AT CPG (CYTOSINE-GUANINE) AND HISTONE H3K9ME2 MARKS IN THE UPSTREAM OF OSHMP. BY IDENTIFYING A COUPLE OF MUTANTS DEFECTIVE IN DNA METHYLATION AND HISTONE MODIFICATION (H3K9ME2) SUCH AS OSMET1 (METHYLATRANSFEASE1) AND OSSDG714 (KRYPTONITE), WE FOUND THAT THE CD-INDUCED EPIGENETIC HYPOMETHYLATION AT THE REGION WAS ASSOCIATED WITH OSHMP OVEREXPRESSION, WHICH CONSEQUENTLY LED TO CD DETOXIFICATION IN RICE. THE CAUSAL RELATIONSHIP WAS CONFIRMED BY THE GUS REPORTER GENE COUPLED WITH OSHMP AND OSMET1 WHEREBY OSMET1 REPRESSED DIRECTLY THE OSHMP EXPRESSION. OUR WORK SIGNIFIES THAT EXPRESSION OF OSHMP IS REQUIRED FOR CD DETOXIFICATION IN RICE PLANTS, AND THE CD-INDUCED HYPOMETHYLATION IN THE SPECIFIC REGION IS RESPONSIBLE FOR THE ENHANCED OSHMP EXPRESSION. IN SUMMARY, THIS STUDY GAINED AN INSIGHT INTO THE EPIGENETIC MECHANISM FOR ADDITIONAL OSHMP EXPRESSION WHICH CONSEQUENTLY ENSURES RICE ADAPTATION TO THE CD-CONTAMINATED ENVIRONMENT. 2021 18 4538 32 MULTISCALE APPROACH TO DECIPHERING THE MOLECULAR MECHANISMS INVOLVED IN THE DIRECT AND INTERGENERATIONAL EFFECT OF IBUPROFEN ON MOSQUITO AEDES AEGYPTI. THE ANTI-INFLAMMATORY IBUPROFEN IS A UBIQUITOUS SURFACE WATER CONTAMINANT. HOWEVER, THE CHRONIC IMPACT OF THIS PHARMACEUTICAL ON AQUATIC INVERTEBRATE POPULATIONS REMAINS POORLY UNDERSTOOD. IN MODEL INSECT AEDES AEGYPTI, WE INVESTIGATED THE INTERGENERATIONAL CONSEQUENCES OF PARENTAL CHRONIC EXPOSURE TO AN ENVIRONMENTALLY RELEVANT CONCENTRATION OF IBUPROFEN. WHILE EXPOSED INDIVIDUALS DID NOT SHOW ANY PHENOTYPIC CHANGES, THEIR PROGENY SHOWED ACCELERATED DEVELOPMENT AND AN INCREASED TOLERANCE TO STARVATION. IN ORDER TO UNDERSTAND THE MECHANISTIC PROCESSES UNDERPINNING THE DIRECT AND INTERGENERATIONAL IMPACTS OF IBUPROFEN, WE COMBINED TRANSCRIPTOMIC, METABOLOMICS, AND HORMONE KINETICS STUDIES AT SEVERAL LIFE STAGES IN EXPOSED INDIVIDUALS AND THEIR PROGENY. THIS INTEGRATIVE APPROACH REVEALED MODERATE TRANSCRIPTIONAL CHANGES IN EXPOSED LARVAE CONSISTENT WITH THE PHARMACOLOGICAL MODE OF ACTION OF IBUPROFEN. PARENTAL EXPOSURE LED TO LOWER LEVELS OF SEVERAL POLAR METABOLITES IN PROGENY EGGS AND TO MAJOR TRANSCRIPTIONAL CHANGES IN THE FOLLOWING LARVAL STAGE. THESE TRANSCRIPTIONAL CHANGES, MOST LIKELY DRIVEN BY CHANGES IN THE EXPRESSION OF NUMEROUS TRANSCRIPTION FACTORS AND EPIGENETIC REGULATORS, LED TO ECDYSONE SIGNALING AND STRESS RESPONSE POTENTIATION. OVERALL, THE PRESENT STUDY ILLUSTRATES THE COMPLEXITY OF THE MOLECULAR BASIS OF THE INTERGENERATIONAL POLLUTANT RESPONSE IN INSECTS AND THE IMPORTANCE OF CONSIDERING THE ENTIRE LIFE CYCLE OF EXPOSED ORGANISMS AND OF THEIR PROGENY IN ORDER TO FULLY UNDERSTAND THE MODE OF ACTION OF POLLUTANTS AND THEIR IMPACT ON ECOSYSTEMS. 2018 19 1174 31 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 20 4924 24 PARENTAL HYPOXIC EXPOSURE CONFERS OFFSPRING HYPOXIA RESISTANCE IN ZEBRAFISH (DANIO RERIO). PARENTAL INFLUENCES ARE A POTENTIALLY IMPORTANT COMPONENT OF TRANSGENERATIONAL TRANSFER OF PHENOTYPE IN VERTEBRATES. THIS STUDY EXAMINED HOW CHRONIC HYPOXIC EXPOSURE ON ADULT ZEBRAFISH (DANIO RERIO) AFFECTED THE PHENOTYPE OF THEIR OFFSPRING. SEPARATE ADULT POPULATIONS WERE EXPOSED TO HYPOXIA (13.1 KPA O(2)) OR NORMOXIA (21.1 KPA O(2)) FOR PERIODS RANGING FROM 1 TO 12 WEEKS. ADULTS WERE THEN RETURNED TO NORMOXIA AND BRED WITHIN EXPERIMENTAL GROUPS. ADULT FECUNDITY AND EGG CHARACTERISTICS (VOLUME OF EGG, YOLK AND PERIVITELLINE FLUID) WERE ASSESSED. SUBSEQUENTLY, LARVAL BODY LENGTH, TIME TO LOSS OF EQUILIBRIUM IN SEVERE HYPOXIA (~4 KPA O(2)), AND CRITICAL THERMAL MINIMA (CT(MIN)) AND MAXIMA (CT(MAX)) WERE MEASURED AT 6, 9, 12, 15, 18, 21 AND 60 DAYS POST-FERTILIZATION (D.P.F.). ADULT FECUNDITY WAS DEPRESSED BY HYPOXIC EXPOSURE. EGG COMPONENT VOLUMES WERE ALSO DEPRESSED IN ADULTS EXPOSED TO 1-2 WEEKS OF HYPOXIA, BUT RETURNED TO CONTROL LEVELS FOLLOWING LONGER HYPOXIC EXPOSURE. ADULT HYPOXIC EXPOSURES OF >1 WEEK RESULTED IN LONGER BODY LENGTHS IN THEIR LARVAL OFFSPRING. TIME TO LOSS OF EQUILIBRIUM IN SEVERE HYPOXIA (I.E. HYPOXIC RESISTANCE) IN CONTROL LARVAE DECREASED FROM 6 TO 12 D.P.F., REMAINING CONSTANT THEREAFTER. NOTABLY, HYPOXIC RESISTANCE FROM 6 TO 18 D.P.F. WAS ~15% LOWER IN LARVAE WHOSE PARENTS WERE EXPOSED TO JUST 1 WEEK OF CHRONIC HYPOXIA, BUT RESISTANCE WAS SIGNIFICANTLY INCREASED BY ~24-30% IN 6-18 D.P.F. LARVAE FROM ADULTS EXPOSED TO 2, 3 OR 4 WEEKS OF HYPOXIA. CT(MIN) (~10-12 DEGREES C) AND CT(MAX) (~39.5 DEGREES C) WERE UNCHANGED BY PARENTAL HYPOXIC EXPOSURE. THIS STUDY DEMONSTRATES THAT PARENTAL HYPOXIC EXPOSURE IN ADULT ZEBRAFISH HAS PROFOUND EPIGENETIC EFFECTS ON THE MORPHOLOGICAL AND PHYSIOLOGICAL PHENOTYPE OF THEIR OFFSPRING. 2012