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According to the results of recent studies, parental exposure to ionizing radiation not only leads to mutation induction in the germline of irradiated animals but also affects their non-exposed offspring. These radiation-induced transgenerational effects belong to an epigenetic phenomenon that could not be defined as a transmission of altered phenotypes from the irradiated parents to their non-exposed offspring. In this review, we present the results of laboratory studies aimed to evaluate the transgenerational effects of parental irradiation on a number of traits in the offspring of exposed parents. The results of animal studies showing compromised viability, fertility and genome stability among the non-exposed offspring of irradiated parents are presented and discussed. So far, the epigenetic phenomenon of radiation-induced transgenerational effects has been established in laboratory studies. Future work should address the important issue of manifestation of radiation-induced transgenerational effects in populations inhabiting radioactive-contaminated areas, as well as the mechanisms of transgenerational effects. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present the results of discussions at a workshop held as part of the International Congress of Radiation Research (Environmental Health stream) in Manchester UK, 2019. The main objective of the workshop was to provide a platform for radioecologists to engage with radiobiologists to address major questions around developing an Ecosystem approach in radioecology and radiation protection of the environment. The aim was to establish a critical framework to guide research that would permit integration of a pan-ecosystem approach into radiation protection guidelines and regulation for the environment. The conclusions were that the interaction between radioecologists and radiobiologists is useful in particular in addressing field versus laboratory issues where there are issues and challenges in designing good field experiments and a need to cross validate field data against laboratory data and vice versa. Other main conclusions were that there is a need to appreciate wider issues in ecology to design good approaches for an ecosystems approach in radioecology and that with the capture of 'Big Data', novel tools such as machine learning can now be applied to help with the complex issues involved in developing an ecosystem approach. [ABSTRACT FROM AUTHOR]

The frequency of mutation is two times as high among children whose parents were exposed to irradiation during the Chernobyl accident in populous areas of the Mogilev district of Belarus than in controls. Five minisatellite probes were used to estimate the rate of mutation. The mutation rate is proportional to the surface contamination levels of cesium-137. Radiation doses in the rural population indicate thyroid exposure to I-131 of 0.185 Gy per person. The increase in minisatellite mutation rate is probably due to an initial exposure to I-131 or chronic exposure to Cs-137.

A retrospective sample survey of birth certificates from a Moscow maternity hospital over a 40-year period has revealed secular growth changes (involving mothers' stature, age at menarche, and four anthropometric traits in newborns) in two consecutive generations. Cohorts of mothers born in the period 1930-1949 showed high rates of acceleration. Age at menarche decreased in these cohorts at a rate of 12.5 months per 10 years, and a parallel gain in stature averaged 1.8 cm per 10 years; both rates were significantly higher than those for Western Europe. In later birth cohorts the acceleration in the maternal generation apparently ended. Anthropometric traits at birth (weight, body length, head and chest circumferences) show different patterns of secular changes from 1950 to 1990. According to multiple regression analysis, a temporal trend in the neonate body size might be mainly due to the parallel increase in mother's stature. The contribution of socioeconomic factors to the observed secular growth changes is discussed., During the past 100-150 years most industrialized countries have revealed a tendency toward increasing velocity of growth and development of children and greater adult stature (Grimm 1966; Cavalli-Sforza and Bodmer [...]

Purpose: To analyze the effects of DNA repair polymorphism and other factors on the frequency chromosome aberrations in an irradiated cohort of subjects living around the Semipalatinsk nuclear test site and non-exposed group of subjects from ecologically favorable zones of Kazakhstan. Materials and methods: Blood samples were collected in the rural areas of the East Kazakhstan district around the Semipalatinsk nuclear test site and ecologically favorable zones of Almaty region of Kazakhstan. Chromosome aberrations in the fresh and cryopreserved peripheral blood lymphocyte cultures were analyzed by Giemsa staining. Single nucleotide polymorphisms at eight DNA repair genes (XRCC1 rs1799782, XRCC1 rs25487, XRCC3 rs861539, ATM rs1801516, XPD rs1799793, XPD rs13181, APEX1 rs1130409, and hOGG1 rs1052133) were determined by PCR-RFLP method. Results: The age of donors and smoking significantly affected the frequency of chromosome aberrations among the irradiated and control subjects. In the irradiated and control cohorts, the frequency of chromosome aberrations was significantly increased in the heterozygous ATM rs1801516 (1853 Asp/Asn) individuals; for the rest of the loci no significant associations between polymorphism and the frequency of chromosome aberrations were detected. Conclusions: The age of donors, smoking, and the ATM rs1801516 polymorphism significantly affect the frequency of chromosome aberrations among individuals inhabiting contaminated area around the Semipalatinsk nuclear weapon test site, as well as among those inhabiting ecologically favorable zones of Kazakhstan. [ABSTRACT FROM AUTHOR]

The molecular basis of species-specific differences in courtship behavior, a critical factor in preserving species boundaries, is poorly understood. Genetic analysis of all but the most closely related species is usually impossible, given the inviability of hybrids. We have therefore applied interspecific transformation of a single candidate behavioral locus, no-on-transient A (nonA), between Drosophila virilis and D. melanogaster, to investigate whether nonA, like the period gene, might encode species-specific behavioral information. Mutations in nonA can disrupt both visual behavior and the courtship song in D. melanogaster. The lovesong of [nonA.sup.diss] mutant males superficially resembles that of D. virilis, a species that diverged from D. melanogaster 40-60 mya. Transformation of the cloned D. virilis nonA gene into D. melanogasterhosts carrying a synthetic deletion of the nonA locus restored normal visual function (the phenotype most sensitive to nonA mutation). However, the courtship song of transformant males showed several features characteristic of the corresponding D. virilis signal, indicating that nonA can act as a reservoir for species-specific information. This candidate gene approach, together with interspecific transformation, can therefore provide a direct avenue to explore potential speciation genes in genetically and molecularly tractable organisms such as Drosophila.

The results of recent studies have provided strong evidence for the transgenerational effects of parental exposure to ionising radiation and chemical mutagens. However, the transgenerational effects of parental exposure on survival and fertility remain poorly understood. To establish whether parental irradiation can affect the survival and fertility of directly exposed organisms and their offspring, crustacean Daphnia magna were given 10, 100, 1000 and 10,000 mGy of acute γ-rays. Exposure to 1000 and 10,000 mGy significantly compromised the viability of irradiated Daphnia and their first-generation progeny, but did not affect the second-generation progeny. The fertility of F 0 and F 1 Daphnia gradually declined with the dose of parental exposure and significantly decreased at dose of 100 mGy and at higher doses. The effects of parental irradiation on the number of broods were only observed among the F 0 Daphnia exposed to 1000 and 10,000 mGy, whereas the brood size was equally affected in the two consecutive generations. In contrast, the F 2 total fertility was compromised only among progeny of parents that received the highest dose of 10,000 mGy. We propose that the decreased fertility observed among the F 2 progeny of parents exposed to 10,000 mGy is attributed to transgenerational effects of parental irradiation. Our results also indicate a substantial recovery of the F 2 progeny of irradiated F 0 Daphnia exposed to the lower doses of acute γ-rays. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the direct and transgenerational effects of exposure to low-dose 1 GHz (mobile phone/wireless telecommunication range) and 10 GHz (radar/satellite communication range) radiofrequency electromagnetic fields (RF-EMF) on the motility of ciliates Spirostomum ambiguum. Materials and methods: S. ambiguum were exposed to 1 GHz and 10 GHz RF-EMF with power flux densities (PD) ranging from 0.05-0.5 W/m2 over a period of time from 0.05-10 h. The motility of directly exposed ciliates and their non-exposed progeny across 10-15 generations was measured. Results: Exposure to 0.1 W/m2 of either 1 or 10 GHz RF-EMF resulted in a significant decrease in the motility. The dose of exposure capable of altering the mobility of ciliates was inversely correlated with the flux density of RF-EMF. The motility of the non-exposed progeny of ciliates irradiated with 0.1 W/m2 of 10 GHz RF-EMF remained significantly compromised, at least, across 10-15 generations, thus indicating the presence of transgenerational effects. Conclusions: The results of our study show that low-dose exposure to RF-EMF can significantly affect the motility of irradiated ciliates and their non-exposed offspring, thus providing further insights into the unknown mechanisms underlying the in vivo effects of RF-EMF. [ABSTRACT FROM AUTHOR]

The non-targeted effects of human exposure to ionising radiation, including transgenerational instability manifesting in the children of irradiated parents, remains poorly understood. Employing a mouse model, we have analysed whether low-dose acute or low-dose-rate chronic paternal γ-irradiation can destabilise the genomes of their first-generation offspring. Using single-molecule PCR, the frequency of mutation at the mouse expanded simple tandem repeat (ESTR) locus Ms6-hm was established in DNA samples extracted from sperm of directly exposed BALB/c male mice, as well as from sperm and the brain of their first-generation offspring. For acute c-irradiation from 10-100 cGy a linear dose-response for ESTR mutation induction was found in the germ line of directly exposed mice, with a doubling dose of 57 cGy. The mutagenicity of acute exposure to 100 cGy was more pronounced than that for chronic low-dose-rate irradiation. The analysis of transgenerational effects of paternal irradiation revealed that ESTR mutation frequencies were equally elevated in the germ line (sperm) and brain of the offspring of fathers exposed to 50 and 100 cGy of acute γ-rays. In contrast, neither paternal acute irradiation at lower doses (10-25 cGy), nor low-dose-rate exposure to 100 cGy affected stability of their offspring. Our data imply that the manifestation of transgenerational instability is triggered by a threshold dose of acute paternal irradiation. The results of our study also suggest that most doses of human exposure to ionising radiation, including radiotherapy regimens, may be unlikely to result in transgenerational instability in the offspring children of irradiated fathers. [ABSTRACT FROM AUTHOR]

Abstract: Germline mutation at eight minisatellite loci has been studied among the irradiated families from the Techa River population and non-exposed families from the rural area of the Chelyabinsk and Kurgan Oblasts. The groups were matched by ethnicity, parental age, occupation and smoking habit. A statistically significant 1.7-fold increase in mutation rate was found in the germline of irradiated fathers, whereas maternal germline mutation rate in the exposed families was not elevated. Most of the minisatellite loci showed an elevated paternal mutation rate in the exposed group, indicating a generalised increase in minisatellite germline mutation rate in the Techa River population. These data suggest that the elevated minisatellite mutation rate can be attributed to radioactive exposure. The spectra of paternal mutation seen in the unexposed and exposed families were indistinguishable. [Copyright &y& Elsevier]

Abstract: Mutation induction in directly exposed cells is currently regarded as the main component of the genetic risk of ionising radiation for humans. However, recent studies showing that exposure to ionising radiation results in elevated mutation rates detectable in the non-irradiated progeny of exposed cells challenge the existing paradigm in radiation biology. This review describes some recent data on radiation-induced genomic instability in vitro and mainly focuses on the in vivo phenomenon of transgenerational instability, where elevated mutation rates are detected in the non-exposed offspring of irradiated parents. The possible mechanisms and implications of transgenerational instability are also discussed. [Copyright &y& Elsevier]

To date, there has been little experimental knowledge on the genetic risks of human exposure to ionising radiation for humans. Recent data suggest that hypervariable tandem repeat minisatellite loci provide a useful and sensitive experimental approach for monitoring radiation-induced germline mutation in humans. Here, I review the results of studies on minisatellite mutation rates in human populations exposed to radioactive fallout after the Chernobyl accident and nuclear weapon tests in Kazakhstan. [Copyright &y& Elsevier]

Human minisatellite B6.7 is a highly variable locus showing extensive heterozygosity with alleles ranging from six to >500 repeat units. Paternal and maternal mutation rates to new length alleles were estimated from pedigrees at 7.0 and 3.9% per gamete, respectively, indicating that B6.7 is one of the most unstable minisatellites isolated to date. Mutation at this locus was also analysed by small pool PCR of sperm and blood DNA. Male germline instability varied from <0.8 to 14% per allele and increased with tandem array size. In contrast, the frequency of mutants in somatic (blood) DNA was far lower (<0.5%), consistent with a meiotic origin of germline mutants. Sperm mutants were further characterized by minisatellite variant repeat mapping using four major polymorphic sites within the B6.7 repeats. This highly informative system revealed a wide variety of changes in allele structure, including simple intra-allelic duplications and deletions and more complicated inter- and intra-allelic transfers of repeat blocks, as seen at other human minisatellites. The main mode of sperm mutation, however, resulted in extremely complex allele reorganization with evidence of inter-allelic transfer plus the generation of novel repeats by rearrangement at the sub-repeat level, suggesting that recombinational instability at B6.7 is a complex multistep process. [ABSTRACT FROM AUTHOR]

Analyzes the secular trend in morphophysiological variation over two generations, namely newborns and their mothers living in Moscow, Russia. Anthropometric traits at birth; Acceleration in maternal generation; Reasons for temporal trend in neonate body size.