Estima de l'heretabilitat d'alguns caràcters mètrics d'una població de drosophila melanogaster del Prat de Llobregat

Hem calculat l'heretabilitat de les microquetes interocel·lars,esternopleurals i abdominals, i de la longitud de la tíbia d'una soca de Drosophila melanogaster del Prat de Llobregat. El metode de calcul utilitzat és el de la regressió de la progenie sobre el progenitor. Llevat de les particularitats relatives a cadascun dels caracters, els valors obtinguts són els que cabia esperar d'acord amb la naturalesa poligenica dels caracters estudiats, i les diferencies deuen tenir, fonamentalment, una base genètica. El fet que els nostres valors siguin intermedis pot ésser degut que la soca estudiada sigui heterozigdtica per a un gran nombre de loci. Les heretabilitats obtingudes fan suposar que els caracters estudiats són determinants poc importants de l'eficacia biologica.The heritability of interocellar, sternopleural and abdominal bristles, and tibia length, was estimated in a natural populations of Drosophila melanogaster from Prat de Llobregat (Barcelona) by the method of parent-offspring regression. The values of the estimated heritability are similar and the differences found must have a genetical basis. Our results are similar to the ones found by other authors witht different polygenic traits and they agree with the nature of the characters. The reason why the found heritabilities are intermediates may be because'the studied population is heterozygotic for a lot of loci

Contribució cromosòmica a la resposta a la selecció de les microquetes interocel.lars de Drosophila Melanogaster

Hem analitzat la importancia que tenen els diferents cromosomes de Drosophila melanogaster en la manifestació del nombre de microquetes interocel·lars i hem evaluat l'efecte de les interaccions cromosomiques. L'experiment s'ha realitzat sobre vuit línies seleccionades, emprant l'analisi substitucional. Els resultats obtinguts indiquen que, malgrat que els tres cromosomes majors són portadors d'agents amb efecte sobre el caracter, la seva importancia relativa depen del tipus de selecció practicada. Així, mentre que a les línies per disminució trobem efecte clar i positiu dels cromosomes X i III, i molt poc efecte del cromosoma Il. a les línies per augment trobem que els cromosomes II i III tenen efecte clar i positiu i que, en canvi, el cromosoma X te efecte negatiu molt fort.The importance of the different chromosomes in the manifestation of interocellar bristles in Drosophila melanogaster has been analysed. This study has been carried out on eight selection lines by means of substitucional analysis. The resultats found show that although on the three major chromosomes are located agents with effect on the studied trait, their relative importance depends on the selection applied. Thus, while in the low lines there is a clear and positive effect in first and third chromosomes, and a mild effect in second chromosome, in the high lines the second and third chromosomes have a clear and positive effect and the first chromosome a very significant and negative effect

Analysis of glutathione and vitamin C effects

The alkaline single-cell gel electrophoresis (or Comet) assay was applied to evaluate the eventual DNA damage induced by the triphenolic metabolite of benzene, 1,2,4-benzenetriol (BT), in isolated human lymphocytes. Prior to BT treatment, ranging from 5 to 50 μM, a supplementation with glutathione (GSH, 350 μg/ml) was carried out to assess whether GSH may have a modulating effect on the Comet response. The effect of a fixed dose of BT was also evaluated in the presence of the exogenous antioxidant vitamin C (40 and 200 μM). Additionally, we investigated whether the polymorphism of glutathione S-transferase T1 (GSTT1) gene may affect the individual level of BT-induced DNA damage in vitro. For all donors included in the present study, BT produced a significant dose-response relationship. No clear effect of GSH preincubation was seen on the BT-induced response. On the contrary, a significant reduction of DNA damage was observed in the presence of vitamin C (at least at 200 μM). Although our data suggest some individual differences according to the GSTT1 genotype in the outcome of the Comet assay, a large number of individuals should be studied in further investigations to obtain reliable conclusions

Genomic Instability in Newborn with Short Telomeres

Telomere length is considered to be a risk factor in adults due to its proved association with cancer incidence and mortality. Since newborn present a wide interindividual variation in mean telomere length, it is relevant to demonstrate if these differences in length can act also as an early risk indicator. To answer this question, we have measured the mean telomere length of 74 samples of cord blood from newborns and studied its association with the basal genetic damage, measured as the frequency of binucleated cells carrying micronuclei. In addition, we have challenged the cells of a subgroup of individuals (N = 35) against mitomycin-C (MMC) to establish their sensitivity to induced genomic instability. Results indicate that newborn with shorter telomeres present significantly higher levels of genetic damage when compared to those with longer telomeres. In addition, the cellular response to MMC was also significantly higher among those samples from subjects with shorter telomeres. Independently of the causal mechanisms involved, our results show for the first time that telomere length at delivery influence both the basal and induced genetic damage of the individual

Sister chromatid exchanges and micronuclei in peripheral lymphocytes of shoe factory workers exposed to solvents.

We examined sister chromatid exchanges (SCEs) and micronuclei (MN; cytokinesis-block method) in cultured peripheral lymphocytes from 52 female workers of two shoe factories and from 36 unexposed age- and sex-matched referents. The factory workers showed an elevated level of urinary hippuric acid, a biomarker of toluene exposure, and workplace air contained high concentrations of various organic solvents such as toluene, gasoline, acetone, and (in one of the plants only) ethylacetate and methylenediphenyl diisocyanate. The shoe factory workers showed a statistically significant higher frequency of micronucleated binucleate lymphocytes in comparison with the referents. This finding agreed with three preliminary MN determinations (each comprising 27-32 shoe workers and 16-20 controls) performed in one of the plants 2-5 years earlier. The shoe factory workers also had a lower average level of blood hemoglobin than the referents. In contrast, no difference was found between the groups in SCE analysis. Smokers showed significantly higher mean frequencies of SCEs per cell and high frequency cells (HFC) than nonsmokers. Aging was associated with increased MN rates and reduced cell proliferation. Polymorphism of the glutathione S-transferase M1 gene (GSTM1) did not affect the individual level of SCEs; but in smoking shoe workers an effect of the occupational exposure on the frequency of micronucleated cells could be seen only in GSTM1 null subjects. The low prevalence of the glutathione S-transferase T1 (GSTT1) null genotype precluded the evaluation of the influence of GSTT1 polymorphism. Our results show that the shoe factory workers have experienced genotoxic exposure, which is manifest as an increase in the frequency of MN, but not of SCEs, in peripheral lymphocytes. The exposures responsible for the MN induction could not be identified with certainty, but exposure to benzene in gasoline and methylenediphenyl diisocyanate may explain some of the findings

Contribució cromosòmica a la resposta a la selecció de les microquetes interocel·lars de Drosophila melanogaster

Hem analitzat la importancia que tenen els diferents cromosomes de Drosophila melanogaster en la manifestació del nombre de microquetes interocel·lars i hem evaluat l'efecte de les interaccions cromosomiques. L'experiment s'ha realitzat sobre vuit línies seleccionades, emprant l'analisi substitucional. Els resultats obtinguts indiquen que, malgrat que els tres cromosomes majors són portadors d'agents amb efecte sobre el caracter, la seva importancia relativa depen del tipus de selecció practicada. Així, mentre que a les línies per disminució trobem efecte clar i positiu dels cromosomes X i III, i molt poc efecte del cromosoma Il. a les línies per augment trobem que els cromosomes II i III tenen efecte clar i positiu i que, en canvi, el cromosoma X te efecte negatiu molt fort.The importance of the different chromosomes in the manifestation of interocellar bristles in Drosophila melanogaster has been analysed. This study has been carried out on eight selection lines by means of substitucional analysis. The resultats found show that although on the three major chromosomes are located agents with effect on the studied trait, their relative importance depends on the selection applied. Thus, while in the low lines there is a clear and positive effect in first and third chromosomes, and a mild effect in second chromosome, in the high lines the second and third chromosomes have a clear and positive effect and the first chromosome a very significant and negative effect

Titanium Dioxide and Zinc Oxide Nanoparticles Are Not Mutagenic in the Mouse Lymphoma Assay But Modulate the Mutagenic Effect of Uv-C-Light Post Treatment

WOS: 000395724300055There are no studies in the literature on nanomaterials (NMs) using gene mutation approaches in mammalian cells, which represents an important gap for genotoxic risk estimations. To fill this gap, mouse lymphoma L5178Y Tk(+/-) assay (MLA) was used to evaluate the mutagenic effect of titanium dioxide and zinc oxide nanoparticles (NPs). Two different NP sizes (between 1-50 and 50-100 nm) of each NP were used. The results indicate that both the selected NMs and their microparticulated forms do not have mutagenic effects. Nevertheless, pre-exposure to these NMs reduce the mutagenic effect of posterior UVC-light exposure, in an indirect concentration-effect relationship. As such, cells previously exposed to low concentrations of the selected NPs show better protective effects against posterior exposure to UVC-light. These in vitro results, obtained from mouse lymphoma cells, support the reproduction of the current literature date on these NPs' genotoxic potential as well as to focus on the discussion on the benefits/risks associated with their use in photo protection sunscreens.Scientific and Technological Research Council of Turkey (TUBITAK), Science Fellowships and Grant Programmes Department (BIDEB), International Post Doctoral Research Fellowship Programme, Ankara (Turkey) [2219]; Generalitat de Catalunya (CIRIT)Generalitat de Catalunya [2014SGR-202]Esref Demir was supported by a postdoctoral fellowship from the Scientific and Technological Research Council of Turkey (TUBITAK), Science Fellowships and Grant Programmes Department (BIDEB), 2219-International Post Doctoral Research Fellowship Programme, Ankara (Turkey). This investigation has been supported in part by the Generalitat de Catalunya (CIRIT, 2014SGR-202). We wish to thank Gloria Umbert for her excellent technical assistance

Polymorphism of glutathione transferase Omega 1 in a population exposed to a high environmental arsenic burden

OBJECTIVES AND METHODS: The aim of this study was to investigate genetic variation in glutathione transferase omega 1 (GSTO1-1) in Atacameños, an indigenous population from Chile that has been exposed to environmental arsenic for many generations. GSTO1

DNA-damage induction by eight metal compounds in TK6 human lymphoblastoid cells: Results obtained with the alkaline Comet assay

Metal compounds are long-lived and can react with different macromolecules, producing a wide range of biological effects, includingDNA damage. Since their reactivity is associated with their chemical structure, it is important to obtain information on more than one compound from the same metal. In this study, the DNA-damaging potential of two mercury compounds (mercury chloride and methyl mercury chloride), two nickel compounds (nickel chloride and potassium hexafluoronickelate), two palladium compounds (ammonium tetrachloropalladate and ammonium hexachloropalladate), and two tellurium compounds (sodium tellurite and sodium tellurate) was evaluated in human lymphoblastoid TK6 cells by use of the alkaline version of the Comet assay. As the use of computerized image-analysis systems to collect comet data has increased, the metric used for quantifying DNA damage was the Olive tail moment. Treatments lasted for 3 h and the range of concentrations tested was different for each metal compound, depending on its toxicity. Both mercury agents produced DNA damage in TK6 cells, with mercury chloride producing considerably more DNA damage than methyl mercury chloride. Of the two nickel compounds, only nickel chloride (a Ni(II) compound) induced DNA breaks. Similarly, of the two palladium compounds, only the Pd(II) compound (ammonium tetrachloropalladate) was positive in the assay. Sodium tellurite was clearly positive, producing concentration-related increases in DNA damage, while sodium tellurate gave a negative response. In conclusion, the ability of inducing DNA damage by the selected metal compounds in human TK6 cells, when measured with the Comet assay, was dependent on the chemical form and, in general, compounds containing the metal in the lower valence state displayed the greater DNA-damaging abilityJRC.F.1-Health in Societ

In vitro DNA damage by arsenic compounds in a human lymphoblastoid cell line (TK6) assessed by alkaline Comet assay

This work focuses on the analysis of genotoxic effects on human peripheral lymphocytes exposed in vitro to arsenic compounds by means of the cytokinesis-block micronucleus assay (CBMN). The study was carried out on three non-smoker healthy males challenged with six arsenic compounds, in trivalent or pentavalent formsuch as sodium arsenite (NaAsO2) and sodium arsenate (NaHAsO4*7H2O) and organoarsenic species such as monomethylarsonous acid (MMAsIII), monomethylarsonic acid (MMAsV), dimethylarsonous acid (DMAsV) and trimethyl arsine oxide (CH3)3AsO (TMAO). For AsIII and AsV at the concentration of 4 M and 32 M respectively an increase of micronuclei (MN) frequency was found. MMAsIII and MMAsV induced a statistically significant increase of MN frequency at the dose of 2 and 500 M respectively. For DMAsV no significant increase of MN was observed, although a decrease of the cytokinesis block proliferation index (CBPI) was evident, indicating a cytotoxic effect. Since the knowledge on the genotoxic effects of the trivalent monomethylated compound is rare or even missing we decided also to evaluate the genotoxic mechanism of action of MMAIII by means of FISH analysis. Due to higher percentage of centromeres positive MN, MMAIII showed a clear aneuploidogenic properties. Finally for TMAO no toxicity was observed up to 1 mM. These results show how speciation is a key factor in determining the cytotoxic effects of As compounds in human peripheral lymphocytes bringing into highlight the need to better understand the molecular mechanisms involved in arsenic poisoning.JRC.I.2-Public Health Policy Suppor