Orientador: Marcelo Carnier Dornelas / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-17T13:26:59Z (GMT). No. of bitstreams: 1 Oliveira_RaphaelRiconde_M.pdf: 18901083 bytes, checksum: be7da78a89962bc71a77edca29ef7399 (MD5) Previous issue date: 2011 / Resumo: A família dos genes MADS-box codifica fatores de transcrição que atuam como reguladores importantes em muitas etapas no desenvolvimento de diversos organismos. Em plantas, estes genes estão envolvidos na determinação da identidade dos meristemas reprodutivos e dos órgãos florais, bem como no controle de diversos processos durante o desenvolvimento. O presente trabalho teve como objetivo estudar o padrão de expressão dos prováveis ortólogos dos genes do modelo ABC (APETALA1, APETALA3, PISTILATA e AGAMOUS de Arabidopsis thaliana, e do gene TM6 de Solanum lycopersicum) em Coffea arabica L. Estes genes pertencem à família MADS-box e estão relacionados à determinação da identidade dos órgãos florais na planta-modelo A. thaliana. A partir do banco de dados de sequências expressas de cafeeiro (CAFEST), foram identificados 23 possíveis homólogos de genes MADS-box em cafeeiro. Perfis de expressão por RT-PCR indicaram que a maioria destes genes são expressos em flor e fruto. A análise dos dados gerados pelo uso de microscopia óptica e de varredura permitiu estabelecer uma sequência de desenvolvimento para estabelecimento dos órgãos florais em cafeeiro, facilitando a identificação dos locais de expressão dos ortólogos do modelo ABC pela técnica de hibridização in situ. Sendo C. arabica uma espécie relativamente recente e com características peculiares, foi proposto um mecanismo de atuação dos genes do modelo ABC. Dessa forma, os resultados obtidos contribuem para a compreensão do estabelecimento dos órgãos florais em C. arabica. Adicionalmente, pela caracterização de um número elevado de genes da família MADS, foram identificados outros genes potencialmente envolvidos em outros processos de desenvolvimento, que futuramente poderão ser utilizados para incremento da indústria cafeeira. / Abstract: The MADS-box gene family encodes transcription factors that act as key regulators in many steps in the development of various organisms. In plants, these genes are involved in determining the identity of reproductive meristems and floral organs as well as in controlling several processes during development. This work aimed to study the expression patterns of putative orthologs of the ABC model genes (APETALA1, APETALA3, AGAMOUS and PISTILATA from Arabidopsis thaliana, and TM6 from Solanum Lycopersicum) in Coffea arabica L. These genes belong to the MADS-box family and are related to the determination of floral organ identity in the model plant A. thaliana. From the CAFEST database of expressed sequence tags, 23 MADS-box gene sequences were identified in coffee. Expression profiles of these genes, determined by RT-PCR, indicated that most of these genes are expressed in flowers and fruits. The analysis of data from optical microscopy and scanning electron microscopy allowed the establishment of a developmental sequence for the establishment of floral organ, facilitating the characterization of the spatial expression patterns of orthologs of the ABC genes by in situ hybridization. A diversified role of conserved genes of the ABC model was proposed for the relatively recent and peculiar specie that is C. arabica. The obtained results aid the understanding of the establishment of floral organs in C. Arabica. Additionally, as many other coffee MADS-box genes were also characterized, other genes, potentially involved in other developmental processes that could be of interest to the industry in the future were also identified. / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal

INTRODUÇÃO: A deleção do cromossomo 9p tem sido encontrada em 14 a 36% dos pacientes com carcinoma renal tipo células claras (CRCC) e está associado a tumores de alto grau, estágio avançado, presença de metástases linfonodais e sistêmicas. OBJETIVOS: Avaliar se a deleção do cromossomo 9p é fator preditor independente de pior sobrevida livre de recorrência e câncer-específica em pacientes com CRCC localizado. MÉTODOS: Neste estudo de coorte retrospectivo, amostras tumorais de 94 pacientes com CRCC NX-0 M0, submetidos à nefrectomia radical ou cirurgia renal conservadora, foram analisadas através das técnicas de microarranjo tecidual e hibridização in situ com fluorescência. RESULTADOS: O tempo de seguimento médio foi de 11,6 anos e a deleção do 9p foi encontrada em cerca de 15% dos casos. A sobrevida câncer específica estimada em 5 e 10 anos foi respectivamente de 99% e 96% nos pacientes sem a referida perda cromossômica e de 71% e 57% naqueles com perda do 9p (p < 0,001). A deleção do cromossomo 9p foi fator prognóstico independente na análise multivariada, aumentando o risco de morte pela doença em 28x (IC 95% 5-155, p < 0,001). Tal deleção foi o preditor mais importante de mortalidade câncer específica, superior a qualquer fator patológico analisado, inclusive ao tamanho tumoral. Em pacientes com baixo risco de progressão, isto é, baixo escore SSIGN (0-2), baixo risco segundo a UISS e baixo risco segundo a Tríade Patológica da USP, tumores deletados do 9p estão significativamente associados com pior sobrevida câncer-específica em 10 anos: respectivamente 70%, 67% e 67% versus 98%, 97% e 98% naqueles sem a perda do 9p. CONCLUSÃO: A deleção do cromossomo 9p estabelece independentemente um pior prognóstico para pacientes com CRCC localizado, fornece informação clínica relevante adicional e pode aperfeiçoar a habilidade preditora dos principais sistemas prognósticos atuais / INTRODUCTION: Deletion of chromosome 9p has been found in 14-36% of patients with clear cell renal cell carcinoma (ccRCC) and is associated with high grade tumors, advanced tumor stage, presence of lymph node involvement and metastases. OBJECTIVES: To assess whether deletion of chromosome 9p is an independent predictor of worse recurrence-free and cancer-specific survival in patients with localized ccRCC. METHODS: In this retrospective cohort study, tumor samples of 94 patients with NX-0 M0 ccRCC undergoing radical nephrectomy or renal conservative surgery, were analyzed using tissue microarray and fluorescence in situ hybridization. RESULTS: Mean follow-up was 11.6 years and 9p deletion was found in near 15% of cases. Estimated cancer-specific survival at 5 and 10 years was, respectively, 99% and 96% in patients without such chromosomal loss and 71% and 57% in those with 9p loss (p < 0.001). Deletion of chromosome 9p is an independent prognostic factor in multivariate analysis, increasing the risk of disease-specific death in 28x (95% CI 5-155, p < 0.001). This deletion was the strongest predictor of cancer-specific mortality, superior to any analysed pathological factor, including tumor size. In patients at low risk of progression, namely low score (0-2) SSIGN, low risk UISS and low risk USP Pathological Triad, 9p-deleted tumors were associated with worse 10 years cancer-specific survival: respectively 70%, 67% and 67% versus 98%, 97% and 98% in those with no 9p loss. CONCLUSIONS: Deletion of chromosome 9p independently establishes a worse prognosis for patients with localized ccRCC, provides relevant additional clinical information and can improve the predictive ability of the main current prognostic models

As ações cardiovasculares decorrentes do tabagismo devem-se principalmente à nicotina. O alcalóide exerce suas funções quando na corrente sangüínea, mas também atravessa a barreira hemato-encefálica onde pode participar da regulação de sistemas de neurotransmissão importantes para o controle central da pressão arterial e, eventualmente, desenvolvimento da hipertensão. Portanto, o abuso à nicotina pode ser especialmente relevante para indivíduos com predisposição genética à hipertensão. Desta forma, os objetivos do presente trabalho foram o de estudar os sistemas de neurotransmissão em núcleos encefálicos envolvidos no controle cardiovascular após tratamento crônico periférico com nicotina, assim como avaliar a influência da nicotina sobre o desenvolvimento da hipertensão essencial em ratos espontaneamente hipertensos (SHR) e compará-los a ratos normotensos (WKY). Para isso, utilizaram-se técnicas como a imunohistoquímica, análise da ligação de receptores, hibridização in situ, cultura de células neuronais e gliais, PCR em tempo Real e Western Blotting. Nossos resultados demonstraram que o tratamento crônico com nicotina não só antecipou o desenvolvimento como também intensificou a hipertensão nos animais SHR. Os ratos WKY não tiveram a pressão arterial alterada. De modo geral, o efeito do alcalóide sobre os sistemas catecolaminérgico e do neuropeptídeo Y não parece ter relação com a antecipação e a intensificação da hipertensão nos ratos SHR. O sistema glutamatérgico está, pelo menos em parte, relacionado à antecipação e intensificação da hipertensão em ratos SHR após exposição crônica à nicotina. O tratamento com nicotina gerou evidências de que o alcalóide interage com o sistema angiotensinérgico a fim de promover a hipertensão em ratos SHR. Por fim, os resultados apresentados aqui indicam que a nicotina modula diferentes sistemas de neurotransmissão, os quais podem estar envolvidos na antecipação e intensificação da hipertensão em ratos SHR submetidos ao tratamento com nicotina. / Nicotine is one of the most important agents for cardiovascular diseases in tobacco smoking. This alkaloid acts in the blood stream, but it also crosses the blood-brain-barrier and participate in the regulation of pivotal neurotransmitter systems for the blood pressure control and, eventually, for hypertension development. In this context, nicotine abuse could be very relevant to individuals carrying genetic factors to hypertension. The objectives of the present work were to study neurotransmitter system in brain cardiovascular areas involved in the control of blood pressure after chronic peripheral nicotine exposure, as well as to evaluate nicotine influence on essential hypertension development in spontaneously hypertensive (SHR) and normotensive rats (WKY). By means of immunohistochemistry, binding, in situ hybridization, neuron and glial culture, real time PCR and Western Blotting, we have demonstrated that chronic treatment with nicotine not only anticipated but also intensified hypertension on SHR. WKY rats did not showed any change on blood pressure. We observed no evidences of the involvement of neuropeptide Y and catecolamines systems in the development of hypertension after nicotine treatment. However, it seems that the glutamatergic system is, at least in part, responsible for the hypertension development after chronic nicotine exposure. To study the angiotensinergic system we cultivated neuron and glial cells from SHR and WKY rats and treated them with nicotine. The responses of this system agree with the hypothesis that nicotine interacts with angiotensin to promote hypertension only in the hypertensive strain. In conclusion, results presented herein support the hypothesis that nicotine modulates neurotransmitter systems that might have relevant functions in the development and intensification of hypertension in SHR.

O benzeno é um hidrocarboneto aromático produzido pela combustão de produtos naturais. A exposição ocupacional ao benzeno é caracterizada por ambientes industriais que o empregam em seus processos produtivos. Nos laboratórios de indústria do petróleo ele é utilizado em forma pura para análise, e está presente como contaminante em derivados, como gasolina, hexano, querosene, tolueno, entre outros. No Brasil o valor recomendado pela legislação como limite de exposição ambiental ao benzeno é de 1ppm. O câncer hematológico é considerado um dos principais fatores de risco para a saúde dos trabalhadores expostos ao benzeno e a utilização de biomarcadores no monitoramento destes profissionais tem sido sugerida em diferentes países. O presente trabalho teve como objetivo avaliar diferentes biomarcadores em sangue periférico de trabalhadores homens, cronicamente expostos ao benzeno em refinarias e siderurgia (18 deles com diagnóstico de intoxicação), que estavam afastados de suas funções por períodos que variaram de cinco meses a 27 anos, com idade média de 46,8 ± 9,33 anos comparado com um grupo controle composto também de 20 homens, selecionados em Bancos de Sangue (idade média de 45,7 ± 8,00 anos), com diferentes ocupações não correlacionadas ao agente em estudo. Em ambos os grupos foram realizados hemograma completo, teste do micronúcleo em linfócitos com bloqueio da citocinese (CBMN), teste de FISH em linfócitos para a translocação t(15;17), bem como testes moleculares para avaliação de polimorfismos em genes envolvidos na metabolização do benzeno (MPO, NQO1, CYP1A1 e CYP2E1) e na eliminação de xenobióticos (GSTM1/GSTT1). Quanto ao hemograma à análise estatística realizada pelo teste t-Student revelou que os expostos ao benzeno apresentavam leucopenia com diferença altamente significante na contagem de leucócitos (p<0,001), neutrófilos (p<0,001), segmentados (p<0,001), linfócitos (p=0,013) e monócitos (p=0,010). A avaliação da série eritrocitária também revelou diferenças estatísticas entre os grupos para os índices de RDW-CV (p= 0,031) e RDW-SD (p=0,008), assim como para o VPM (p=0,001). Não foi verificada diferença entre os grupos quanto à frequência de polimorfismos nos genes CYP1A1, CYP2E1, MPO, NQO1, GSTM1, GSTT1. No teste do CBMN a contagem de células com MN e pontes núcleoplasmáticas foi três vezes maior nos expostos (1,95 ± 2,37) que nos controles (0,65 ± 0,75), diferença essa considerada estatisticamente significante (t=2,33; 38gl; p=0,024). Na análise de FISH para o rearranjo PML/RAR? os trabalhadores expostos também apresentaram frequência três vezes maior de células com pelo menos uma fusão gênica (9,79 ± 9,54) em comparação aos controles (3,95 ± 3,17), diferença essa considerada estatisticamente significante pelo teste t-Student (p=0,019). Os resultados obtidos na presente investigação parecem estar de acordo com os dados da literatura que revelam alteração nas células primordiais da medula, decorrente da exposição ocupacional ao benzeno, bem como ação genotóxica, identificada pelos testes do CBMN e FISH em linfócitos de sangue periférico. Embora o número de trabalhadores estudados seja reduzido, e a exposição ocupacional possivelmente inclua outros agentes potencialmente genotóxicos que não só o benzeno é interessante ressaltar que os resultados positivos foram observados após em média nove anos de afastamento profissional. A utilização do teste do CBMN e o estudo de outras translocações, que não só a PML/ RAR?, em linfócitos de trabalhadores expostos pode representar um biomonitoramento importante e menos invasivo no acompanhamento destes trabalhadores. A análise de um grupo maior de trabalhadores, inclusive expostos a baixas concentrações de benzeno pode ser fundamental na validação destes biomarcadores. / Benzene is an aromatic hydrocarbon produced by the burning of natural products. The occupational exposure to benzene is characterized by industrial environments that use in their production processes. In the laboratories of Petroleum industry it is used in the pure form for analysis, and it is present as a contaminant in other products like gasoline, hexane, kerosene, toluene, etc. In Brazil the threshold limit value recommended by law in environmental exposure to benzene is 1 ppm. The hematological cancer is considered one of the main risk factors for the health of workers occupationally exposed to benzene and the use of biomarkers in monitoring these professionals has been suggested in different countries. The aim of this study was to assess different biomarkers in peripheral blood lymphocytes from 20 men workers chronically exposed to benzene in Petroleum Refinery and Steel Industry (18 workers with poisoning diagnosis), who were removed from workplace for periods ranging from five months to 27 years, with average age 46.8 ± 9.33 years old compared to a control group consisting also of 20 men, selected in Blood Banks (average age 45.7 ± 8.00 years old), with different occupations unrelated to the agent under study. In both groups were performed blood cell counts, cytokinesis-block micronucleus assay (CBMN), FISH assay in peripheral blood lymphocytes for translocation t(15;17), and molecular tests for evaluation of genetic polymorphisms in genes involved in benzene metabolism (MPO, NQO1, CYP1A1 e CYP2E1) and detoxification (GSTM1/GSTT1). Despite blood cell counts the statistical analysis performed by t-Student test revealed that workers exposed to benzene had leukopenia with a highly significant difference in leukocyte count (p<0.001), neutrophils (p<0.001), segmented (p<0.001), lymphocytes (p=0.013) and monocytes (p=0.010). The evaluation of red blood cells also revealed statistically significant differences between groups for RDW-CV (0.031), RDW-SD (0.008) and MPV (0.001). There were no differences between groups regarding the frequency of genetic polymorphisms in CYP1A1, CYP2E1, MPO, NQO1, GSTM1, and GSTT1. In the CBMN test the cell counts with MN and nucleoplasmic bridges was three times higher in exposed (1.95 ± 2.37) than in controls (0.65 ± 0.75), and the difference was considered statistically significant (t=2.33;38gl;p=0.024). In the FISH analysis for the PML/RAR? rearrangement the exposed workers also showed three times higher frequency of cells with at least one signal fusion (9.79 ± 9.54) in comparison to controls (3.95 ± 3.17), and the difference was statistically significant by the t-Student test (p=0.019). The results obtained in this study seem to agree with the literature data that show alterations in the stem cells of the bone marrow, resulting from occupational exposure to benzene, as well genotoxicity, identified by CBMN and FISH assay in peripheral blood lymphocytes. Although the number of subjects evaluated is reduced, and the occupational exposure includes other potentially genotoxic agents not only benzene, it is interesting to note that positive results were observed after an average of nine years of removal professional. The use of the CBMN test and the study of other translocations, not only PML/ RAR?, in lymphocytes of workers exposed may represent an important biomonitoring and less invasive monitoring of workers. The analysis of a major number of individuals, including those exposed to low concentrations of benzene, may be essential in validation of these biomarkers.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-01T12:31:29Z No. of bitstreams: 1 grazielatoledocostamayrink.pdf: 5985830 bytes, checksum: 06ca10d53dd3ecb4c31ad3500ea80e8c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-02T15:13:59Z (GMT) No. of bitstreams: 1 grazielatoledocostamayrink.pdf: 5985830 bytes, checksum: 06ca10d53dd3ecb4c31ad3500ea80e8c (MD5) / Made available in DSpace on 2017-06-02T15:13:59Z (GMT). No. of bitstreams: 1 grazielatoledocostamayrink.pdf: 5985830 bytes, checksum: 06ca10d53dd3ecb4c31ad3500ea80e8c (MD5) Previous issue date: 2016-08-10 / Introdução: A associação entre Linfoma de Hodgkin clássico e o status tumoral do vírus Epstein- Barr é bem definida. Entretanto, a expressão da positividade do vírus Epstein-Barr nas células de Reed-Sternberg/Hodgkin e o impacto dessa relação na sobrevida do Linfoma de Hodgkin clássico permanecem controversos e apresentam resultados conflitantes em estudos de diversas regiões do mundo. Considera-se essencial o entendimento fisiopatogênico desse vírus no prognóstico dos pacientes com Linfoma de Hodgkin clássico. Objetivo: Correlacionar o status do vírus Epstein Barr com os fatores de risco desfavoráveis e fatores prognósticos do Linfoma de Hodgkin clássico em uma população brasileira. Métodos: A positividade do vírus Epstein-Barr foi determinada pelo método de Hibridização in situ para o ácido ribonucleico viral e pela imuno-histoquímica para proteína de membrana latente viral 1. A revisão histopatológica das amostras e a análise dos testes de identificação foram realizadas por uma hematopatologista experiente. Avaliou-se o impacto prognóstico do status do vírus Epstein-Barr em 29 pacientes com Linfoma de Hodgkin clássico. Os fatores prognósticos do Escore Prognóstico Internacional para estadio avançado e os fatores de risco desfavoráveis instituídos pelo Grupo Alemão de Estudos em Hodgkin para estadio limitado foram correlacionados com o status viral nas células tumorais. Para as associações entre presença do vírus Epstein-Barr e outras variáveis categóricas, aplicaram-se os testes de Qui-quadrado ou exato de Fisher. A Sobrevida Global e a Sobrevida Livre de Eventos foram analisadas pelo método de Kaplain-Meier e Modelo de Regressão Proporcional de Cox. Resultados: A média de idade ao diagnóstico foi 33 anos. O status do vírus Epstein-Barr nas células tumorais foi positivo em 37,9%. As células tumorais positivas para o vírus foram mais frequentes em pacientes com idade maior que 45 anos, sem diferença estatística. O subtipo celularidade mista foi o mais frequente (p = 0,02) e o tamanho de efeito desse teste foi de moderada magnitude. Na análise univariada, as sobrevidas Livre de Eventos e Global não apresentaram significância estatística para idade, sexo, estadio clínico, hemoglobina, leucocitose, linfocitopenia, albumina, envolvimento nodal, sintomas B, doença extranodal e doença Bulky entre os pacientes positivos e negativos para o vírus Epstein-Barr (p > 0,05). Os pacientes positivos apresentaram maior Sobrevida Livre de Eventos quando comparados aos pacientes negativos, embora a diferença não apresentasse significância (p = 0,07). Na análise multivariada, a positividade ao vírus Epstein-Barr não demonstrou fator prognóstico significante. Conclusões: Apesar do status do vírus Epstein-Barr nas células tumorais não ter revelado associação com fatores prognósticos adversos e não ter influenciado a Sobrevida Global e a Sobrevida Livre de Eventos, observou-se uma associação positiva entre a presença desse vírus e o subtipo celularidade mista, demonstrando uma relação com o subtipo histológico de pior prognóstico. / Introduction: The association between classical Hodgkin’s Lymphoma and tumor Epstein-Barr virus status is well established. However, the expression of Epstein-Barr virus presence in Hodgkin/Reed-Sternberg cells and its prognosis remains controversial and presentes conflicting results in studies worldwide. Understanding the pathophysiological role of this virus in the prognosis of patients with classical Hodgkin’s Lymphoma is essential. Objective: The aim of this study is to correlate the clinical outcome with Epstein-Barr virus status in a Brazilian population. Methods: Epstein-Barr virus positivity was determined by in situ hybridization for Epstein-Barr virus-encoded ribonucleic acid and immunohistochemistry for viral latent membrane protein-1. The histopathology review and the analysis of identification tests were performed by an hematopathologist expert. The prognostic impact of Epstein-Barr virus status in 29 patients with classical Hodgkin’s Lymphoma was evaluated. Prognostic factors from International Prognostic Score to advanced stage and risk factors from German Hodgkin Study Group to limited stage were correlated with tumor cells Epstein-Barr virus status. In order to determine associations between the presence of Epstein-Barr virus and other categorical variables, Chi-square or Fisher's exact tests were applied. Overall and event-free survivals were analyzed with Kaplan-Meier method and Cox proportional hazards regression models. Results: The mean age at diagnosis was 33 years. Tumor cells Epstein-Barr virus status was positive in 37.9%. Epstein-Barr virus-positive classical Hodgkin’s Lymphoma was more frequent in patients older than 45 years, with no statistical difference. Mixed cellularity histological subtype was more common in Epstein-Barr virus-related tumor cells (p = 0.02) and its effect-size index was medium. Univariate analysis, event-free survival and overall survival were not significantly associated to age, sex, clinical stage, hemoglobin, leukocytes, lymphocytes, albumin, nodal involvement, B symptoms, extranodal disease and Bulky disease in Epstein-Barr virus-positive and negative patients (p > 0.05). Epstein-Barr virus-positive patients had longer event free survival when compared to Epstein-Barr virus-negative ones, even though the difference was not statistically significant (p = 0.07). In multivariate analysis, Epstein Barr virus positivity was not a significant prognostic factor. Conclusions: Although the Epstein-Barr virus status in tumor cells was not associated with adverse prognostic factors and did not influence the overall and event-free survivals, a positive association between the presence of Epstein-Barr virus and Mixed-cellularity subtype was noticed.

Axolotl uniquely generates blastema cells as a pool of progenitor/stem cells to restore an entire limb, a particular property that other organisms, such as humans, do not have. What underlies these differences? Is the main difference that cells residing at the amputation plane (in the stump) undergo reprogramming processes to re-enter the embryonic program, which allows developmental patterning to start, or are there fundamental differences? There is also a significant debate about whether regeneration occurs via stem cell differentiation or by dedifferentiation of mature limb tissue. The aim of my thesis was to address following questions: Are the cells in the blastema reprogrammed or differentiated to regenerate? Are the blastema cells genetically reactivated de novo during regeneration? How does the amputated limb exactly know which part of the limb needs to be regenerate? Using a novel technique of long-term genetic fate mapping, my team demonstrated that dedifferentiation in regenerated axolotl muscle tissue does not occur. Instead, PAX7+ satellite cells indeed play an important role during muscle regeneration in the axolotl limb. Surprisingly, this is in contrast to the newt, which regenerates muscle cells through a dedifferentiation process. Therefore, there is a fundamental difference that underlies the regenerative mechanism ((Sandoval-Guzman et al., 2014) [KR1]). This demonstrates that there is an unexpected diversity and flexibility of cellular mechanims used during limb regeneration, even among two closely related species. Finally, if one salamander species uses a mammalian regenerative strategy (Cornelison and Wold, 1997; Collins et al., 2005) involving stem cells and another uses a dedifferentiative strategy, this raises the question of whether there are other fundamental aspects of regeneration that could also be anomalous. This hypothesis is promising since there could be more than one possible mechanism to induce mammalian regeneration. The process of limb regeneration in principle seems to be more similar to those of limb development as historically assumed. We showed molecularly that embryonic players are reused during regeneration by reactivating the position- and tissue-specific developmental gene programs by using the newly isolated Twist sequences as early blastema cell markers ((Kragl et al., 2013) [KR2]). To gain insights into the molecular mechanisms of the P/D limb patterning in general, it was crucial to study the early patterning events of the resident progenitor/stem cells by using the specific blastema cell marker HoxA as a positional marker along the proximo-distal axis. Our HOXA protein analysis using high molecular and cellular resolution as well as transplantation assays demonstrated for the first time that axolotl limb blastema cells acquire their positional identity in a proximal to distal sequence. We found a hierarchy of cellular restrictions in positional identities. Amputation at the level of the upper arm showed that the blastema harbors cells, which convert to lower arm and hand. We observed ((Roensch et al., 2013) [KR3]) for the first time that intercalation- the intermediate element (lower arm) arises later from an interaction between the proximal and distal cells identities- does not occur. Intercalation, which has been an accepted model for a long time, is not the patterning mechanism underlying normal (without any manipulation) limb regeneration that is unique to axolotl. We further demonstrated, using the Hox genes as markers that positional identity is cell-type specific since their effects were confirmed to be present in the lateral plate mesoderm- derived cells of the limb. As our knowledge about limb blastemas expands concerning cell composition and molecular events controlling patterning, the similarity to development is becoming more and more clear. My work has resolved many ambiguities surrounding the molecularly identification of different types of blastema cells and how P/D limb patterning occurs during regeneration in comparison to development. It has highlighted the importance of combining high-resolution methods, such as in situ hybridizations, single-cell PCR (sc-PCR) of individual dissociated blastema cells and genetic labeling methods with grafting experiments to map cell fates in vivo. In addition to understanding the processes of regeneration, another long-term goal in the regenerative medicine field is to identify key molecules that trigger the regeneration of tissues. Recently, my colleague Takuji Sugiura (Sugiura et al., 2016) observed that an early event of blastema formation is the secretion of molecules like MLP (MARCKS-like protein), which induces wound-associated cell cycle re-entry. Such findings further increase the enthusiasm of biologists to understand the underlying principles of regeneration. By building our knowledge of the molecules and pathways that are involved in tissue regeneration, we increase the possibility of identifying a way to ‘activate’ regenerative processes in humans and thus reach the final goal of regenerative medicine, which is to use the concepts of cellular reprogramming, stem cell biology and tissue engineering to repair complex body structures.

Extensive serotonin (5-HT) fiber innervation throughout the brain corroborates 5-HT’s modulatory role in numerous behaviors including social behavior, emotion regulation, and learning and memory. Abnormal brain 5-HT levels and function are implicated in Autism Spectrum Disorder (ASD) which often co-occurs with other neuropsychiatric conditions. While 5-HT therapeutics are used to treat ASD, variable improvements in symptomatology require further investigation of 5-HT-mediated pathology. Neurexins (Nrxns) are presynaptic cell adhesion molecules that maintain synapse function for proper neural circuit assembly. Given that aberrant Nrxn and 5-HT function independently contribute to signaling pathology and behavioral impairments, it is critical to understand how Nrxn-mediated 5-HT neurotransmission participates in pathological mechanisms underlying ASD. Using fluorescence in situ hybridization, I found that the three Nrxn genes (Nrxn1, Nrxn2, and Nrxn3) are differentially expressed in 5-HT neurons in the dorsal raphe nucleus (DRN) and median raphe nucleus which contain the primary source of 5-HT neurons in the brain. Our lab generated a mouse model with selective deletion of Nrxns in 5-HT neurons to investigate the function of Nrxns in 5-HT signaling. The loss of Nrxns at 5-HT release sites reduced 5-HT release in the DRN and hippocampus and altered 5-HT innervation in specific brain regions. The lack of 5-HTergic Nrxns also reduced sociability and increased depressive-like behavior in males. This mouse model provides mechanisms to shed new light on 5-HT neurotransmission in the generation of complex behaviors.

The main aim of this study was to determine the changes in neuronal activity of anterior cingulate cortex (ACC), orbitofrontal cortex (OFC) and medial prefrontal cortex (MPC) in rats sensitized to D2/D3 receptor agonist quinpirole (QNP) during exploration of enriched open field arena. During the experiment, the evaluation of behavioural changes induced by quinpirole sensitization were also assessed and compared to previous results. For the purpose of this study, twenty-two adult male Long-Evans rats were used. The half of the rats was sensitized to QNP by receiving daily subcutaneous injections of quinpirole (0,5 mg/kg) while the other half received saline. Both groups were habituated for ten days to open-field arena enriched with two metal objects. The behaviour of animals was videotaped and the data about locomotion and the number of visits of each locale was obtained. On the eleventh day, the part of saline and quinpirole treated groups explored the open-field arena (t = 5 min) while the other two subgroups were left as respective cage-controls. Immediately after the end of experiment, all rats were sacrificed, and the extracted brains were cryopreserved. To determine the changes in neuronal activity of selected brain regions, fluorescence in situ hybridization of immediate early gene Arc was...

1 Abstract: The diploma thesis focuses on study of sex chromosomes evolution and repetitive organized genes of chosen mygalomorph and araneomorph spiders. Spiders are characterized by complexicity of sex chromosome systems, their karyotypes contain multiple sex chromosomes X. Besides multiple X chromosomes they also contain a pair or two pairs of nondiferentiated sex chromosomes X and Y. The used methods include methods of classical cytogenetics (preparation of chromosome slides, C-banding) and methods of molecular cytogenetics (fluorescent in situ hybridization and comparative genome hybridization). Complex sex systems were discovered in the studied Theraphosidae spiders. In Theraphosidae spiders Atropothele socotrana and Poecilotheria vittata neo-sex chromosomes were found. Analysis of molecular differentiation of sex chromosomes suggests low differentiation of Y chromosome in neo-sex chromosomes and pair of nondifferentiated sex chromosomes XY. In haplogyne spider Kukulcania aff. hibernalis (X1X2Y), the Y chromosome was significantly differentiated, male specific signal covered the whole chromosome. Detection of 18S rDNA showed that karyotypes of majority of analysed Theraphosidae spiders and haplogyne spiders contain low number (1 or 2) of nucleolar organizing regions localized terminally, which...

Karyotypes of mygalomorph spiders are not satisfactorily known. This thesis is focused on the basic cytogenetic analysis of selected species of African clades of theraphosid mygalomorphs. It includes four subfamilies: Eumenophorinae, Harpactirinae, Ischnocolinae and Stromatopelminae. Diploid numbers, chromosome morphology, sex chromosome systems and chromosome behaviour in male germline in the selected species of African theraphosid subfamilies were studied. The findings support published results, that refer of high karyotype diversity in Theraphosidae. Diploid chromosome number reduction is probably a basic trend of theraphosid karyotype evolution. The majority of analysed species exhibited one, two or three sex chromosomes. In some species neo-sex chromosome systems were found. In some species one or two sex chromosome pairs (SCP), composed of chromosomes which lack morphological differentiation were detected. Nucleolus organizer regions were detected by fluorescent in situ hybridization in several species. Constitutive heterochromatin detection was performed by C-banding in two species. Keywords: constitutive heterochromatin, diploid number, karyotype, fluorescence in situ hybridization, Mygalomorphae, nucleolus organizer region, SCP, sex chromosome, spider, Theraphosidae