Spray application of 5­azacytidine on established plant seedlings was tested for its demethylating efficiency, as it represents a novel method for plant experimental demethylation with a potentially lower negative impact on plant development compared to the traditional application of the demethytaling agent through germination of seeds in its solution. Further, the 5­azacytidine spray application was used in practice to erase the epigenetic memory in offspring of Taraxacum brevicorniculatum plants from different competitive conditions. The impact of parental competition on the juvenile phenotype was estimated by measuring growth related traits, while the experimental demethylation allowed for evaluating the significance of DNA methylation marks in bioticaly induced transgenerational effects in T. brevirorniculatum.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-05-03T18:25:52Z No. of bitstreams: 1 2016 - Camila Mendon?a Netto Jobim.pdf: 2312664 bytes, checksum: b9e51b7bf56f9bfc3fabc284e20448e8 (MD5) / Made available in DSpace on 2017-05-03T18:25:52Z (GMT). No. of bitstreams: 1 2016 - Camila Mendon?a Netto Jobim.pdf: 2312664 bytes, checksum: b9e51b7bf56f9bfc3fabc284e20448e8 (MD5) Previous issue date: 2016-05-25 / Anxiety is one of the most common psychiatric disorder in society. This disorders may occur as a result of an individual?s inability to face a stress event (physical or emotional), which can happen in youth or adulthood. The exposure to stressors during the perinatal period can cause consequences for life. Thus environmental enrichment is used either as preventive or attenuating stressor events. The aim of this study was to evaluate the behavioural response related to anxiety on the offspring of females mice raised in an enriched environment during their perinatal period. Experimentally was created male and female groups during tree generation (F0, F1 and F2). Animals was raised in standard environment (P) and enriched environment (E) in F0. In the next generation (F1), females that was born in E was placed to P and composed the E-P group. Therefore, in F2 we had the P, E-P and E group. This group had their maternal behavior observed, submitted to behavioral models, plasmatic corticosterone assayed as well the expression of the AVP1a, AVP1b, CRH1, CRH2 and OT receptors. As results, we verify that the enriched environment only in F0 changed the maternal behavior (46,8?8,9% P; 77,8?5,4% E; p=0,0138). The anxiolytic effect was noted in all the models applied. In elevated plus maze it was observed in E group during all the generation. Only in F2, the E group showed anxiolytic effect in open field test. On light-dark box, the E-P and E group was different of P in latency to explore the light part in F1 and F2. The last generation, F2, was tested and showed a different latency to eat the pellet in novelty suppressed feeding test. The E group had the shortest time to eat the pellet, followed by E-P and P had the biggest (147,7?15,7s; 101,4?8,8s; 62,8?9,4s; F=13,0700 p=0,0001 - male) (143,7?11,4s; 93,7?20,4s; 38,3?5,3s; F=16,1900 p<0,0001 - female). The transgeracional effect could be visualized in light-dark box and novelty suppressed feeding tests because the E-P group had their behavior similar to E even that had not been directly exposed to the enriched environment. There is no difference between sexes in results of the models. The neuroendocrine analyzes there no significate result. Then, we suggest that transgenerational effect is due to exposure of the dams to the environmental enrichment during perinatal period. / Os transtornos de ansiedade est?o entre as doen?as psiqui?tricas mais comuns na sociedade. Eles se d?o pela incapacidade do indiv?duo em lidar com um evento estressor (f?sico ou emocional), podendo acometer desde a inf?ncia at? a idade adulta. O desencadeamento da ansiedade no per?odo perinatal pode acarretar em mudan?as comportamentais ao longo da vida. Neste sentido, o enriquecimento ambiental ? utilizado tanto como atenuante dos efeitos estressores quanto como preventivo. Sendo assim, buscou-se avaliar comportamentos relacionados ? ansiedade de filhotes de f?meas expostas ao enriquecimento ambiental durante per?odo perinatal. Para isso foram criados grupos de machos e f?meas ao longo de tr?s gera??es-F0, F1 e F2. Em F0 foram montados 2 grupos, o padr?o (P) e o enriquecido (E). Em F1 f?meas que estavam em ambiente enriquecido durante o per?odo perinatal foram passadas para o ambiente padr?o formando o grupo enriquecimento-padr?o (E-P). F2 ent?o passou a ter grupos dos tr?s grupos, P, E-P e E. Estes grupos foram submetidos a observa??es do comportamento materno, modelos de ansiedade, dosagem de corticosterona plasm?tica e a avalia??o da express?o dos genes para os receptores AVP1a, AVP1b, CRH1, CRH2 e OT. Como resultados verificamos que o comportamento materno em F0 foi maior no grupo enriquecido (E) (46,8?8,9% P; 77,8?5,4% E; p=0,0138), por?m n?o em F1 (68,4?4,1% P; 71,1?6% E-P; 78,1?3,1% E; F=0,8120 p=0,4689). Foi constatado o efeito ansiol?tico nos modelos comportamentais utilizados. No labirinto em cruz elevado-LCE, este efeito pode ser notado apenas no grupo E das tr?s gera??es avaliadas. No campo aberto CA, apenas o grupo E de F2 apresentou comportamentos relacionados a ansiedade significativamente diferentes dos demais grupos. O teste da caixa claro-escuro-CCE mostrou diferen?a entre os grupos E-P e E em rela??o ao grupo P na lat?ncia para explorar o ambiente claro em F1 e F2. E o teste da supress?o da alimenta??o pela novidade-NSF indicou que os grupos s?o diferentes entre si na lat?ncia para se alimentar, o maior tempo foi de P, seguido de E-P e depois de E (147,7?15,7s; 101,4?8,8s; 62,8?9,4s; F=13,0700 p=0,0001 - Machos) (143,7?11,4s; 93,7?20,4s; 38,3?5,3s; F=16,1900 p<0,0001 - F?meas). Pode ser constado o efeito transgeracional em CCE e NSF, onde a exposi??o da m?e ao enriquecimento influenciou o comportamento dos filhotes que n?o foram diretamente expostos ao ambiente enriquecido. Todos os resultados dos modelos comportamentais valem para machos e f?meas e n?o h? diferen?as em rela??o ao g?nero. Os par?metros neuroend?crinos analisados n?o mostraram diferen?a significativa entre os grupos. Sugere-se ent?o que o efeito transgeracional se deu apenas pela exposi??o das m?es ao ambiente enriquecido no per?odo perinatal e manifestou-se comportamentalmente.

Environmental conditions can influence epigenetic variability of clonal organisms. These environmentally induced changes have potential to persist in following generations. In theory, this transgenerational memory could allow clonal (and especially apomictic) plants to partly compensate reduced genetic variability and could enhance adaptative ability of apomictic populations. According to Muller's ratchet model, asexual organisms amass deleterious mutations, which could lead to their extinction. Possible transgenerational memory could partly compensate for this. It could also account for longtime survivorship of asexual organisms in environment. This thesis deals with transgenerational memory of triploid apomictic populations of Hieracium alpinum, with completely missing sexuality and thus genetically uniform offspring. Transgenerational effect in Hieracium alpinum was studied on clonal lineages originated from 5 populations (Norway, Austria, Bosnia and Herzegovina and Slovakia). Seeds were planted in cultivation experiment I in 3 treatments (control, added nutrients, added salicylic acid) and vegetative and generative traits were measured. Plants responded to nutrient addition but not to salicylic acid. Treatment with nutrient addition increased biomass, number of leaves and SLA (specific leaf...

Objective: To determine if paternal preconception exposure to ionizing radiation through uranium mining increases the risk of congenital anomaly (CA) in offspring. Methods: A population-based matched case-control study was conducted. Cases were infants with CAs recorded in the Canadian Congenital Anomalies Surveillance System and born alive in Ontario 1979-86 (ICD-9 codes 740-759); controls were liveborn infants without CAs identified from Ontario birth certificates and individually matched to cases (case-control file {CCF}). Exposed fathers were identified through the linkage of the CCF to the Mining Master File or the National Dose Registry file, which include those who worked in Ontario uranium mines 1952-1986. For men who linked with a case or control child, radon, gamma and total gonadal doses were estimated for three preconception periods: entire, 3-months and 6-months. Odds ratios were estimated using conditional logistic regression. Results: Linkage of 28,991 uranium miners and 40,482 case-control pairs of fathers and offspring in the CCF identified 431 discordant pairs. There was no evidence of increased risk of a child having a CA if the father was ever a uranium miner before conception of the child (OR=0.89, 95% CI=0.74–1.08). Since gamma radiation (especially during the 6-month preconception period) is more biologically relevant to gonads than radon, further analyses were performed on 117 discordant pairs where data on gamma exposures were available. When ever/never miner, exposed to gamma (yes/no), and gamma dose-response variables were all in the model, there was no ever/never miner effect (OR=1.20, 95% CI=0.85–1.69, p-value=0.30), an inverse association for exposure to gamma (OR=0.42, 95% CI=0.25–0.71, p-value=0.001), but most importantly, there was no statistically significant dose-response relationship between gamma dose during the 6-month preconception period and all CAs (OR=1.15 per loge {mSv+0.01}, 95% CI=0.83–1.59, p-value=0.40). Similarly, no dose-response relationship was observed for exposure to gamma radiation in the 3-month preconception period, or for radon or total gonadal radiation in the 3- or 6-month preconception periods. Conclusion: There was no increased risk of a CA among liveborn children of Ontario uranium miners who were exposed to radon, gamma or total radiation during the 3- or 6-month periods before conception.

Objective: To determine if paternal preconception exposure to ionizing radiation through uranium mining increases the risk of congenital anomaly (CA) in offspring. Methods: A population-based matched case-control study was conducted. Cases were infants with CAs recorded in the Canadian Congenital Anomalies Surveillance System and born alive in Ontario 1979-86 (ICD-9 codes 740-759); controls were liveborn infants without CAs identified from Ontario birth certificates and individually matched to cases (case-control file {CCF}). Exposed fathers were identified through the linkage of the CCF to the Mining Master File or the National Dose Registry file, which include those who worked in Ontario uranium mines 1952-1986. For men who linked with a case or control child, radon, gamma and total gonadal doses were estimated for three preconception periods: entire, 3-months and 6-months. Odds ratios were estimated using conditional logistic regression. Results: Linkage of 28,991 uranium miners and 40,482 case-control pairs of fathers and offspring in the CCF identified 431 discordant pairs. There was no evidence of increased risk of a child having a CA if the father was ever a uranium miner before conception of the child (OR=0.89, 95% CI=0.74–1.08). Since gamma radiation (especially during the 6-month preconception period) is more biologically relevant to gonads than radon, further analyses were performed on 117 discordant pairs where data on gamma exposures were available. When ever/never miner, exposed to gamma (yes/no), and gamma dose-response variables were all in the model, there was no ever/never miner effect (OR=1.20, 95% CI=0.85–1.69, p-value=0.30), an inverse association for exposure to gamma (OR=0.42, 95% CI=0.25–0.71, p-value=0.001), but most importantly, there was no statistically significant dose-response relationship between gamma dose during the 6-month preconception period and all CAs (OR=1.15 per loge {mSv+0.01}, 95% CI=0.83–1.59, p-value=0.40). Similarly, no dose-response relationship was observed for exposure to gamma radiation in the 3-month preconception period, or for radon or total gonadal radiation in the 3- or 6-month preconception periods. Conclusion: There was no increased risk of a CA among liveborn children of Ontario uranium miners who were exposed to radon, gamma or total radiation during the 3- or 6-month periods before conception.