No description available.

Amphibian populations are declining world-wide and one of the suggested reasons is environmental pollutants. Studies of long-term effects on the reproductive system in frogs following larval exposure to environmental pollutants are scarce. It is therefore important to develop methods to study developmental reproductive toxicity in amphibians. In this thesis the usefulness of Xenopus tropicalis (the West African clawed frog) as a model species for a test system was investigated. Effects on the reproductive system after larval exposure to the pharmaceuticals ethynylestradiol (EE2) and clotrimazole were evaluated. The susceptibility to EE2 exposure was compared between the model species and a wild species, the European common frog (Rana temporaria). Larval exposure to EE2 caused female-biased sex ratios in both examined frog species, indicating male-to-female sex-reversal. In adult Xenopus tropicalis, male frogs that were not sex-reversed had reduced fertility and decreased amount of mature spermatozoa in the seminiferous tubules. The proportion of frogs with ovaries but lacking oviducts increased with increasing EE2-concentrations. A female frog without oviducts is sterile. The development of ovaries in sex-reversed male frogs was implied to be similar to control females. The combination of a reduced number of males, due to sex-reversal, and impaired fertility could have severe effects on frog populations. Larval exposure to clotrimazole modulated aromatase activity in gonads and brain in Xenopus tropicalis. Brain aromatase activity was decreased at the time for gonadal differentiation and gonadal aromatase activity was increased at metamorphosis. The findings in this thesis indicate that reproduction in wild frogs might be impaired by estrogenic compounds in the environment. The results combined with the short generation time supports the use of Xenopus tropicalis as a model species when evaluating long term effects of endocrine disruptors on the reproductive system in amphibians.

The study emerges against a global and local backdrop of longstanding oppression and stigmatization of gays and lesbians, due to their sexual orientation. Regardless of transformative policies in South Africa which declare equal acceptance, treatment and inclusion of gay and lesbian citizens, prejudice and unfair discrimination still exists. The study investigates the experiences of gays and lesbians living in the Inanda area of Durban, KwaZulu-Natal in South Africa with the view to developing a greater understanding of their experiences and realities of ‘otherness’ and oppression. The conceptual model which frames the study is based on the generic model of social identity development and general model of oppression put forward by Hardiman and Jackson (1997), offering a useful lens through which to better identify oppression in the experiences and realities of gays and lesbians. The focus on understanding human experiences locates the study firmly within a qualitative research design. This focus also led to the selection of personal narratives as the strategy of inquiry, thereby allowing the researcher to enter worlds of experiences different from her own. Face- to- face, semi-structured interviews with eight participants (four gays and four lesbians, between the ages of twenty one and twenty five) comprised the method of data generation. The participants were selected as a result of a snowballing sample method. All live near each other in the Inanda area and are in regular social contact with each other. While research using a small sample of eight participants from the Inanda area cannot claim to be a comprehensive study into the experiences of gays and lesbians in all South African communities, these narratives reflect to a large degree, experiences of ‘otherness’ and oppression common to all gay and lesbian people. / M. Ed. University of KwaZulu-Natal, Durban 2014.

Orientadores: Maricilda Palandi de Mello, Celso Eduardo Benedetti, Fernanda Caroline Soardi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T21:27:39Z (GMT). No. of bitstreams: 1 CunhaJunior_JoseLuizRosenberis_M.pdf: 3002580 bytes, checksum: 1980aba7f72fdfd74e758a924771c055 (MD5) Previous issue date: 2010 / Resumo: A expressão do gene SRY (Sex Determining Region in chromosome Y) é responsável por desencadear a determinação testicular durante o desenvolvimento embrionário, a partir das gônadas ainda indiferenciadas. Mutações nesse gene são encontradas em muitos casos de anomalias do desenvolvimento gonadal. O projeto teve por objetivo principal a análise funcional do efeito de uma mutação na região promotora do gene SRY, sendo que essa mutação consiste em uma deleção de 3 pares de base em um dos sítios consenso de ligação do fator de transcrição Sp1 ao promotor do gene. O portador dessa mutação é um indivíduo com disgenesia gonadal pura 46,XY, sendo que outros membros da família apresentavam ambiguidade genital e o pai, também portador da mutação, possuía grave hipospadia ao nascimento. Para tentar esclarecer os efeitos desta mutação nos mecanismos moleculares de regulação da expressão do gene SRY, este trabalho primeiramente analisou a interação da proteína Sp1 com os sítios localizados na região promotora de SRY e o efeito da mutação nesta interação, através de ensaios de EMSA (Electrophoretic Mobility Shift Assay). Concluiu-se que os sítios Sp1A e Sp1B se ligam a duas moléculas de Sp1 e que a mutação no Sp1A praticamente abole esta ligação. Possivelmente a ausência dessa ligação impediu a formação de um complexo de transcrição, causando uma diminuição na expressão do gene SRY e levando à ausência de formação dos testículos e reversão sexual completa na paciente. Complementando, foi analisado o efeito dessa mutação na expressão através de ensaio de expressão com gene repórter, no qual o promotor normal se mostrou em média duas vezes mais eficiente na ativação da expressão da luciferase que o promotor mutante. Entretanto, mais experimentos de transfecção, inclusive com outras linhagens celulares, devem ser realizados para confirmação desse resultado. Além disso, foi analisado o efeito de uma nova mutação (localizada na região codificante do gene SRY) na ligação da proteína SRY com o DNA, através de ensaios de EMSA. Concluiu-se que a mutação E89K, associada com disgenesia gonadal pura 46,XY, reduziu em alto nível a atividade de ligação in vitro da proteína SRY mutante ao DNA, o que representa um forte indício de que atividade reduzida da proteína mutante não foi suficiente para desencadear o processo de determinação testicular. Paralelamente, foi feito o rastreamento de mutações no gene SRY e sua região promotora em novos casos de disgenesia gonadal, não tendo sido encontradas, porém, alterações nos pacientes analisados / Abstract: The SRY (Sex Determining Region in chromosome Y) gene expression is responsible for testicular determination during embrionary development. Mutations in SRY are found in many cases of anomalies of gonadal development. This project analyzed the functional effect of a mutation in SRY promoter region; the mutation is a 3-bp deletion in a consensus binding site for Sp1 transcription factor. The patient presented 46,XY pure gonadal dysgenesis, and a family history of relatives with different levels of genital ambiguity. Her father shares the same mutation in the SRY promoter region. In order to investigate the effects of the mutation upon the molecular mechanisms that regulate SRY gene expression, the interaction of the Sp1 transcription factor with normal and mutant binding sites was analyzed by EMSA (Electrophoretic Mobility Shift Assay). Each of Sp1A and Sp1B normal sites binds to a single Sp1 molecule, whereas the 3-bp deletion in Sp1A abolishs the binding to this site. Probably, the lack of Sp1 binding to the Sp1A site prevented the formation of a stable transcription complex, reducing the level of SRY expression and leading to the absence of testicles and complete sex reversal in the patient. Parallely, the effect of the mutation was analyzed by a reporter gene assay, indicating that the normal promoter is almost two times more efficient than the mutant promoter in the activation of luciferase gene expression using HeLa cells. However, further transfection experiments with other cell lineages must be performed to confirm this result. In addition, the effect of a new mutation (E89K, located in the SRY gene coding region) was analyzed by testing the ability of the SRY mutant protein to bind its DNA consensus sequence. EMSA assays revealed that the E89K mutation, which is associated with 46,XY pure gonadal dysgenesis, strongtly reduced the SRY protein binding activity in vitro. This result is a strong evidence that the reduced activity of SRY mutant protein was not sufficient to trigger the testicular determination in the patient, leading to the pure gonadal dysgenesis phenotype. Screening of mutations in the SRY gene coding and promoter regions was also performed in six diferent patients with 46,XY gonadal dysgenesis. However, other mutations have not been identified / Mestrado / Genetica Animal e Evolução / Mestre em Genética e Biologia Molecular

No description available.

Anti-müllerian hormone (AMH) is expressed in male embryos and represses development of müllerian ducts during testis differentiation in mammals, birds and reptiles. Amh orthologues have been identified in teleosts despite them lacking müllerian ducts. Previously we found sexually dimorphic aromatase activity in tilapia brains before ovarian differentiation. This prompted us to search for further dimorphisms in tilapia brains during sex differentiation and see whether amh is expressed. We cloned the tilapia amh gene and found that it contains 7 exons but no spliced forms. The putative protein presents highest homologies with Amh proteins of pejerrey and medaka as compared to other Perciformes. We analysed amh expression in adult tissues and found elevated levels in testes, ovary and brain. Amh expression was dimorphic with higher levels in XY male brains at 10–15 dpf, when the gonads were still undifferentiated and gonadal amh was not dimorphic. Male brains had 2.7-fold higher amh expression than gonads. Thereafter, amh levels decreased in the brain while they were up-regulated in differentiating testes. Our study indicates that amh is transcribed in male brains already at 10 dpf, suggesting that sexual differentiation may be occurring earlier in tilapia brain than in gonads. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

A investigação do sexo é uma das análises mais importantes na identificação humana. Este trabalho teve como objetivo a determinação do sexo em crânios humanos utilizando três métodos de Antropologica Física, duas quantitativas (Forensic Data Anthropolgy Bank, FDB, 1986 e Oliveira, 1995) e uma qualitativa, (Walker, 2008), e a análise genética pela amelogenina. A amostra foi composta de 66 crânios (34 homens e 32 mulheres) do Centro de Estudo e Pesquisa em Ciências Forenses, Guarulhos, SP. As metodologias foram aplicadas por duas pesquisadoras, que desconheciam o sexo dos crânios. Para o estudo estatístico realizaram-se análise descritiva, média, desvio padrão, análise discriminante linear e logística e regressão logística. A metodologia quantivativa apresentou um acerto de 89,52%. O Método FBD teve uma acurácia de 92,31%, com a elaboração de uma fórmula utilizando as medidas Largura Bizigomática, Altura Nasal, as quais apresentaram o maior dimorfismo entre os sexos, e Altura Básio-bregma e Máximo Comprimento do Crânio. A metodologia de Oliveira et al. (1995) necessitou de ajuste para a população estudada (nova fórmula com acurácia de 76,47% em homens e 78,13% em mulheres). Para o DNA, foi possível determinar o sexo em 86,15% da amostra. Pode-se afirmar que as diferentes metodologias comportaram-se de modo semelhante e com alta acurácia para determinação do sexo. A antropologia física apresenta as vantagens de facilidade de aplicação, reprodutibilidade e baixo custo, porém, necessita de ajustes populacionais. O DNA é mais complexo, necessita de infraestrutura e insumos específicos e pode ter interferência da condição ambiental, fatores que dificultam as análises, entretanto, não precisa ser ajustado á população. / The investigation of the sex is one of the most important analyzes in the human identification. This study aimed to determine the sex in human skulls using three methodologies of Physical Anthropology, two quantitative (Forensic Data Anthropology Bank, FDB, 1986 e Oliveira, 1995) and one qualitative (Walker, 2008) and genetic analysis by amelogenin. The sample was composed by 66 skulls (34 men and 32 women) from the Center for Study and Research in Forensic Science, Guarulhos, SP. The methodologies were applied by two researchers who were unaware of the craniums sexes. For the statistical analysis, there were performed descriptive analysis, average, standard deviation, linear discriminant analysis and logistic and logistic regression. The quantitative methodology presented an accuracy of 89.52%. The FBD method had an accuracy of 92.31%, with the development of a mathematical model using the measures Bizygomatic breadth, Nasal heigh, which showed the biggest dimorphism between the sexes, and Basion-bregma height and Maximum Cranial Length. The Oliveiras et al. (1995) methodology required adjustment for the studied population (new formula with an accuracy of 76.47% in men and 78.13% in women). For the DNA, it was possible to determine the sex in 86.15% of the sample. The different methodologies behaved similarly and with high accuracy in sex determination. Physical anthropology has the advantages of being easy to use, reliability and low cost, but needs population adjustments. The DNA is more complex, requires specific reagents and structure and may have interference from environmental condition, however, does not need to be adjusted to the population.

A investigação do sexo é uma das análises mais importantes na identificação humana. Este trabalho teve como objetivo a determinação do sexo em crânios humanos utilizando três métodos de Antropologica Física, duas quantitativas (Forensic Data Anthropolgy Bank, FDB, 1986 e Oliveira, 1995) e uma qualitativa, (Walker, 2008), e a análise genética pela amelogenina. A amostra foi composta de 66 crânios (34 homens e 32 mulheres) do Centro de Estudo e Pesquisa em Ciências Forenses, Guarulhos, SP. As metodologias foram aplicadas por duas pesquisadoras, que desconheciam o sexo dos crânios. Para o estudo estatístico realizaram-se análise descritiva, média, desvio padrão, análise discriminante linear e logística e regressão logística. A metodologia quantivativa apresentou um acerto de 89,52%. O Método FBD teve uma acurácia de 92,31%, com a elaboração de uma fórmula utilizando as medidas Largura Bizigomática, Altura Nasal, as quais apresentaram o maior dimorfismo entre os sexos, e Altura Básio-bregma e Máximo Comprimento do Crânio. A metodologia de Oliveira et al. (1995) necessitou de ajuste para a população estudada (nova fórmula com acurácia de 76,47% em homens e 78,13% em mulheres). Para o DNA, foi possível determinar o sexo em 86,15% da amostra. Pode-se afirmar que as diferentes metodologias comportaram-se de modo semelhante e com alta acurácia para determinação do sexo. A antropologia física apresenta as vantagens de facilidade de aplicação, reprodutibilidade e baixo custo, porém, necessita de ajustes populacionais. O DNA é mais complexo, necessita de infraestrutura e insumos específicos e pode ter interferência da condição ambiental, fatores que dificultam as análises, entretanto, não precisa ser ajustado á população. / The investigation of the sex is one of the most important analyzes in the human identification. This study aimed to determine the sex in human skulls using three methodologies of Physical Anthropology, two quantitative (Forensic Data Anthropology Bank, FDB, 1986 e Oliveira, 1995) and one qualitative (Walker, 2008) and genetic analysis by amelogenin. The sample was composed by 66 skulls (34 men and 32 women) from the Center for Study and Research in Forensic Science, Guarulhos, SP. The methodologies were applied by two researchers who were unaware of the craniums sexes. For the statistical analysis, there were performed descriptive analysis, average, standard deviation, linear discriminant analysis and logistic and logistic regression. The quantitative methodology presented an accuracy of 89.52%. The FBD method had an accuracy of 92.31%, with the development of a mathematical model using the measures Bizygomatic breadth, Nasal heigh, which showed the biggest dimorphism between the sexes, and Basion-bregma height and Maximum Cranial Length. The Oliveiras et al. (1995) methodology required adjustment for the studied population (new formula with an accuracy of 76.47% in men and 78.13% in women). For the DNA, it was possible to determine the sex in 86.15% of the sample. The different methodologies behaved similarly and with high accuracy in sex determination. Physical anthropology has the advantages of being easy to use, reliability and low cost, but needs population adjustments. The DNA is more complex, requires specific reagents and structure and may have interference from environmental condition, however, does not need to be adjusted to the population.

Made available in DSpace on 2015-07-22T20:49:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-31 / We report here on a girl who, despite her 45,X/46,X,der(Y) karyotype, showed no signs of virilization or physical signs of the Ullrich-Turner syndrome [UTS], except for a reduced growth rate. After prophylactic gonadectomy due to the risk of developing gonadoblastoma, the gonads and peripheral blood samples were analyzed by fluorescence in situ hybridization [FISH] and polymerase chain reaction [PCR] to detect Y-specific sequences. These analyses allowed us to characterize the Yderived chromosome as being an isodicentric Yp chromosome [idic(Yp)] and showed a pronounced difference in the distribution of the 45,X/46,X,idic(Yp) mosaicism between the two analyzed tissues. It was shown that, although in peripheral blood almost all cells (97.5%) belonged to the idic(Yp) line with a duplicated SRY gene, this did not determine any degree of male sexual differentiation in the patient, as in the gonads the predominant cell line was 45,X (60%). / TEDE / BV UNIFESP: Teses e dissertações

Anti-müllerian hormone (AMH) is expressed in male embryos and represses development of müllerian ducts during testis differentiation in mammals, birds and reptiles. Amh orthologues have been identified in teleosts despite them lacking müllerian ducts. Previously we found sexually dimorphic aromatase activity in tilapia brains before ovarian differentiation. This prompted us to search for further dimorphisms in tilapia brains during sex differentiation and see whether amh is expressed. We cloned the tilapia amh gene and found that it contains 7 exons but no spliced forms. The putative protein presents highest homologies with Amh proteins of pejerrey and medaka as compared to other Perciformes. We analysed amh expression in adult tissues and found elevated levels in testes, ovary and brain. Amh expression was dimorphic with higher levels in XY male brains at 10–15 dpf, when the gonads were still undifferentiated and gonadal amh was not dimorphic. Male brains had 2.7-fold higher amh expression than gonads. Thereafter, amh levels decreased in the brain while they were up-regulated in differentiating testes. Our study indicates that amh is transcribed in male brains already at 10 dpf, suggesting that sexual differentiation may be occurring earlier in tilapia brain than in gonads. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.