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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Diversidade genética, sistema de reprodução e fluxo de pólen e sementes em uma população fragmentada de Myracrodruon urundeuva (F.F. & M.F. Allemão) para fins de conservação genética

Gaino, Ana Paula Silva Campos [UNESP] 30 October 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-10-30Bitstream added on 2014-06-13T20:06:58Z : No. of bitstreams: 1 gaino_apsc_dr_ilha.pdf: 1851631 bytes, checksum: 30c3df7caf28f5a913484aa675c16225 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os objetivos deste estudo foram investigar por locos microssatélites, a diversidade genética, o sistema de reprodução, a distribuição espacial de genótipos, a distância e os padrões de dispersão de pólen e sementes, e a dinâmica da endogamia entre gerações, em uma população fragmentada da espécie arbórea dióica Myracrodruon urundeuva (F.F. & M.F. Allemão). O estudo foi conduzido na Estação Ecológica de Paulo de Faria (435,73 ha), onde a população da espécie em estudo ocupa uma área aproximada de 142 ha. Todas as 467 árvores adultas encontradas foram amostradas, tiveram o diâmetro à altura do peito (DAP a 1,3 m) medido e foram mapeadas. Adicionalmente amostraram-se 149 regenerantes e 514 progênies de polinização aberta, coletadas de 30 árvores matrizes da população. Sobre a amostra total de cinco locos em 1130 genótipos (adultos + regeneração + progênies) foram observados 60 alelos, o que sugere um nível de polimorfismo relativamente alto. O número de alelos por loco variou de 7 a 25, com média de 12 alelos por loco. A heterozigosidade esperada média em equilíbrio de Hardy-Weinberg foi de 0,662, enquanto que a heterozigosidade observada foi de 0,713. O índice de fixação variou de -0,348 a 0,215 entre locos, com média de -0,076, sugerindo excesso de heterozigotos. A análise da distribuição espacial dos genótipos indicou a presença de estrutura genética espacial (EGE) na população adulta até aproximadamente 40 m e nos regenerantes até aproximadamente 30 m. Foram detectados cruzamentos entre parentes, pela diferença entre a unidade e a taxa de cruzamento uniloco (st1=0,019, P<0,05). A estimativa da correlação de paternidade ()(mpr) indicou que as progênies são compostas por misturas de meios-irmãos e irmãos-completos, embora estes últimos em menor proporção (média de 0,158) O coeficiente de coancestria (Θxy) dentro das progênies... / The aims of this study were to investigate for microsatellites loci the genetic diversity, mating system, the intrapopulational spatial genetic structure, the distance and patterns of pollen dispersal, and the dynamics of inbreeding among generations, in a fragmented population of the dioicious tropical tree Myracrodruon urundeuva (F.F. & M.F. Allemão). The study was carried out in the Paulo de Faria Ecological Station (435.73 ha), where the studied population occupies about 142 ha. All 467 adult trees found in the stand were sampled, have the diameter at breast height (D.B.H of 1.3 m) measured and were mapped. Additionally 149 juveniles and 514 open-pollinated offspring from 30 seed-trees were sampled in the population. On the total of five loci sampled in 1135 genotypes (adults + juveniles + offspring), 60 alelos were detected, suggesting a relative high level of polimorphis. The number of alleles per locus ranged from 7 to 25 alleles, with average of 12 alleles. The average expected heterozygositys in Hardy-Weinberg equilibrium was of 0.662, were the average observed heterozygosity was of 0.713. The fixation index ranged among locus from -0.348 to 0.215, with average of -0.076, suggesting excess of heterozygous. The analysis of the intra-population spatial genetic structure (SGS) detected the presence of SGS in adults until about 40 m and in juveniles until about 30 m. Mating among relatives were also detected by the difference between the unit and the single-locus outcrossing rate ( s t 1 =0.019; P<0.5). The paternity correlation ( p (m ) r ) indicated that the offspring were composed by mixtures of half-sibs and full-sibs, where the last one occurred in low frequency (average of 0.158). The coancestry coefficient (Θxy) within families was larger than expected in half-sibs (Θxy=0.125), with population average of 0.150. The variance effective population size (eN) within... (Complete abstract click electronic access below)
62

Diversidade genética, sistema de reprodução e fluxo de pólen e sementes em uma população fragmentada de Myracrodruon urundeuva (F.F. & M.F. Allemão) para fins de conservação genética /

Gaino, Ana Paula Silva Campos. January 2009 (has links)
Orientador: Alexandre Magno Sebbenn / Banca: Mario Luiz Teixeira de Moraes / Banca: Pedro Cesar dos Santos / Banca: Rinaldo César de Paula / Banca: Edwin Camacho Palomino / Resumo: Os objetivos deste estudo foram investigar por locos microssatélites, a diversidade genética, o sistema de reprodução, a distribuição espacial de genótipos, a distância e os padrões de dispersão de pólen e sementes, e a dinâmica da endogamia entre gerações, em uma população fragmentada da espécie arbórea dióica Myracrodruon urundeuva (F.F. & M.F. Allemão). O estudo foi conduzido na Estação Ecológica de Paulo de Faria (435,73 ha), onde a população da espécie em estudo ocupa uma área aproximada de 142 ha. Todas as 467 árvores adultas encontradas foram amostradas, tiveram o diâmetro à altura do peito (DAP a 1,3 m) medido e foram mapeadas. Adicionalmente amostraram-se 149 regenerantes e 514 progênies de polinização aberta, coletadas de 30 árvores matrizes da população. Sobre a amostra total de cinco locos em 1130 genótipos (adultos + regeneração + progênies) foram observados 60 alelos, o que sugere um nível de polimorfismo relativamente alto. O número de alelos por loco variou de 7 a 25, com média de 12 alelos por loco. A heterozigosidade esperada média em equilíbrio de Hardy-Weinberg foi de 0,662, enquanto que a heterozigosidade observada foi de 0,713. O índice de fixação variou de -0,348 a 0,215 entre locos, com média de -0,076, sugerindo excesso de heterozigotos. A análise da distribuição espacial dos genótipos indicou a presença de estrutura genética espacial (EGE) na população adulta até aproximadamente 40 m e nos regenerantes até aproximadamente 30 m. Foram detectados cruzamentos entre parentes, pela diferença entre a unidade e a taxa de cruzamento uniloco (st1=0,019, P<0,05). A estimativa da correlação de paternidade ()(mpr) indicou que as progênies são compostas por misturas de meios-irmãos e irmãos-completos, embora estes últimos em menor proporção (média de 0,158) O coeficiente de coancestria (Θxy) dentro das progênies... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aims of this study were to investigate for microsatellites loci the genetic diversity, mating system, the intrapopulational spatial genetic structure, the distance and patterns of pollen dispersal, and the dynamics of inbreeding among generations, in a fragmented population of the dioicious tropical tree Myracrodruon urundeuva (F.F. & M.F. Allemão). The study was carried out in the Paulo de Faria Ecological Station (435.73 ha), where the studied population occupies about 142 ha. All 467 adult trees found in the stand were sampled, have the diameter at breast height (D.B.H of 1.3 m) measured and were mapped. Additionally 149 juveniles and 514 open-pollinated offspring from 30 seed-trees were sampled in the population. On the total of five loci sampled in 1135 genotypes (adults + juveniles + offspring), 60 alelos were detected, suggesting a relative high level of polimorphis. The number of alleles per locus ranged from 7 to 25 alleles, with average of 12 alleles. The average expected heterozygositys in Hardy-Weinberg equilibrium was of 0.662, were the average observed heterozygosity was of 0.713. The fixation index ranged among locus from -0.348 to 0.215, with average of -0.076, suggesting excess of heterozygous. The analysis of the intra-population spatial genetic structure (SGS) detected the presence of SGS in adults until about 40 m and in juveniles until about 30 m. Mating among relatives were also detected by the difference between the unit and the single-locus outcrossing rate ( s t 1 =0.019; P<0.5). The paternity correlation ( p (m ) r ) indicated that the offspring were composed by mixtures of half-sibs and full-sibs, where the last one occurred in low frequency (average of 0.158). The coancestry coefficient (Θxy) within families was larger than expected in half-sibs (Θxy=0.125), with population average of 0.150. The variance effective population size (eN) within... (Complete abstract click electronic access below) / Doutor
63

Variação genética para caracteres silviculturais e marcador molecular em uma população base de Eucalyptus camaldulensis Dehnh

Alves, Patrícia Ferreira [UNESP] 27 February 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-27Bitstream added on 2014-06-13T19:39:04Z : No. of bitstreams: 1 alves_pf_me_ilha.pdf: 1156996 bytes, checksum: b15b4fc65711b183e64e0ad1b0e86836 (MD5) / O Eucalyptus camaldulensis destaca-se pelo potencial de utilização de sua madeira, como também pela sua plasticidade de adaptação a diferentes condições ambientais brasileiras. Dessa forma, se utilizou duas metodologias, para avaliar uma população base de E. camaldulensis, originária da Austrália, e instalada em Selvíria-MS em abril de 1986. A primeira procurou avaliar a variação genética para os caracteres silviculturais: altura total, altura comercial, altura da primeira bifurcação, diâmetro a altura do peito e volume; como também da qualidade da madeira como a resistência à penetração e a densidade básica da madeira. Para tanto, utilizou-se um delineamento em blocos casualizados com 25 progênies, 4 repetições e 1 planta por parcela. As estimativas de componentes de variância e parâmetros genéticos foram obtidas pelo método da máxima verossimilhança restrita e melhor predição linear não viciada (REML/BLUP). Verificou-se que: i) não se detectou variação genética para os caracteres silviculturais e da qualidade da madeira; ii) o caráter mais indicado para a seleção foi à altura comercial (HC) em função dos maiores coeficientes de variação relativa ( = 0,32), herdabilidade (rCV2mhˆ = 0,28) e da acurácia ( = 0,54) encontrados; iii) a população de E. camaldulensis apresenta bom desenvolvimento silvicultural (HT = 25,36m) na região do bolsão sul-matogrossense; iv) a alta densidade básica da madeira (DBM = 0,74) desta população de E. camaldulensis indica este material para uso em serraria e energia (carvão e lenha). A segunda metodologia procurou avaliar a diversidade genética e o sistema reprodutivo desta população, por meio de marcador microssatélite. Para tanto, foram amostrados tecidos foliares em 100 árvores de uma população de E. camaldulensis localizada na Fazenda de Ensino e Pesquisa da UNESP de Ilha Solteira, situada... / The Eucalyptus camaldulensis is distinguished for the potential of use of its wood, as well as for its plasticity of adaptation the different Brazilian ambient conditions. Of this form, if it used two methodologies, to evaluate a population base of E. camaldulensis, originary of Australia, and installed in Selvíria-MS in April of 1986. The first one looked for to evaluate the genetic variation for the silvicultural traits: total height, commercial height, height of the first bifurcation, breast height diameter and volume; as well as of the wood quality as the resistance to the penetration and the wood density. The experimental design utilized was a randomized block with 25 progenies, four replications and one plant for plot was used. The genetic estimates of variance components and parameters had been gotten by the method of the restricted maximum likelihood and best linear unbiased prediction (REML/BLUP). It was verified that: i) did not detect genetic variation for the silvicultural traits and of the quality of the wood; ii) the indicated trait more for the election was to the commercial height (HC) in function of the biggest coefficients of relative variation ( = 0,32), heritability (rCV2mhˆ = 0,28) and of the accuracy ( = 0,54) found; iii) the population of E. camaldulensis presents good aarˆsilvicultural development (HT = 25,36m) in the region of the south-matogrossense; iv) the high wood density (DBM = 0,74) of this population of E. camaldulensis indicates this material for use in would saw and energy (coal and firewood). The second methodology looked for to evaluate the genetic diversity and the mating system of this population, by means of marking microsatellite. For in such a way, they had been showed leaves in 100 E. camaldulensis trees of a population located in the Farm of Education and Research of the UNESP in Selvíria-MS. It was observed that the nine evaluated locos... (Complete abstract click electronic access below)
64

Seleção sexual e evolução do dimorfismo sexual em duas espécies de opiliões (Arachnida: Opiliones) / Sexual selection on male weaponry in two neotropical harvestmen (Arachnida: Opiliones)

Camila Zatz de Oliveira Santos 15 April 2010 (has links)
Ainda que existam diversos registros de formas extremas de dimorfismo sexual, a função do alongado quarto par de pernas nos machos de muitas espécies de opiliões permanece desconhecida. Neste estudo, testamos quatro previsões sobre a hipótese de que a seleção sexual está direcionando o alongamento do quarto par de pernas nos machos de Longiperna zonata e Promitobates ornatus: (1) o coeficiente alométrico do comprimento do fêmur IV em machos será maior do que o das fêmeas; (2) machos com pernas IV mais compridas vão residir próximos a grupos de fêmeas; (3) machos envolvidos em interações agressivas terão fêmures mais compridos do que o tamanho médio da população; (4) a diferença de tamanho de perna entre os oponentes será menor do que a diferença esperada entre pares de machos escolhidos ao acaso na população. Como o previsto, o coeficiente alométrico do fêmur IV foi significativamente maior em machos do que em fêmeas nas duas espécies. O comprimento do fêmur IV está positivamente relacionado à chance de um macho ser encontrado próximo a um grupo de fêmeas. Finalmente, a média do comprimento do fêmur IV dos machos envolvidos em brigas foi significativamente maior que a de machos selecionados ao acaso da população. Adicionalmente, a média da diferença de tamanho entre pares de machos que brigaram foi significativamente menor que a média da diferença de tamanho de perna entre pares de machos selecionados ao acaso na população. Assim, a seleção sexual na forma de competição entre machos parece estar direcionando o dimorfismo sexual extremo no comprimento do fêmur nessas duas espécies de opiliões. / Although there are many reports of extreme forms of sexual dimorphism in harvestmen, the function of the elongated fourth pair of legs in males of many species remains unknown. We tested four predictions to address the hypothesis that sexual selection is driving the enlargement of the fourth pair of legs in males of Longiperna zonata and Promitobates ornatus: (1) the allometric coefficient of femur IV length in males will be higher than in females; (2) males with longer legs IV will reside closer to groups of females; (3) males involved in aggressive interactions will have longer femur IV than the population average size; (4) the size difference between contenders will be smaller than the difference expected between randomly chosen pairs of males in the population. As predicted, the allometric coefficient of femur IV length was significantly higher in males than in females of both species. Femur IV length was positively related to the chance of a male being found close to a group of females. Finally, the mean femur IV length of the males involved in fights was significantly larger than the mean of random samples of males from the population, and the average difference between male contenders was smaller than the average random expected difference of the population. Therefore, sexual selection in the form of male-male competition seems to be driving the extreme sexual dimorphism in femur length in these species.
65

Sistema reprodutivo e fluxo gênico via pólen em uma coleção de germoplasma de Eugenia dysenterica DC. / Mating system and pollen-mediated gene flow in a germplasm collection of Eugenia dysenterica DC.

Rodrigues, Eduardo Borges 03 September 2012 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-26T13:04:27Z No. of bitstreams: 2 Dissertação - Eduardo Borges Rodrigues - 2012.pdf: 6019074 bytes, checksum: f7a43bf329af77b351ce74ec756dc615 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-26T13:04:48Z (GMT) No. of bitstreams: 2 Dissertação - Eduardo Borges Rodrigues - 2012.pdf: 6019074 bytes, checksum: f7a43bf329af77b351ce74ec756dc615 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-26T13:04:48Z (GMT). No. of bitstreams: 2 Dissertação - Eduardo Borges Rodrigues - 2012.pdf: 6019074 bytes, checksum: f7a43bf329af77b351ce74ec756dc615 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2012-09-03 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The success of any breeding program or genetic resources conservation depends on the knowledge about gene flow, reproductive system and genetic variability in the studied populations. For perennial plants, germplasm collection maintained ‘in vivo’ and ‘ex situ’ can be an efficient method for conserving the genetic variability of a species is maintained outside its original habitat. This study aimed to evaluate the reproductive system and pollen-mediated gene flow in one generation of Eugenia dysenterica DC. from the germoplasma collection of the Escola de Agronomia e Engenharia de Alimentos from Universidade Federal de Goiás. We collected leaves from 404 adult plants and seeds from 23 mother-trees in the germplasm collection. Genotypes were obtained using eight microsatellite loci, four of them developed for E. dysenterica, and four transferred from Eucalyptus spp. The total number of alleles was 88, ranging from 4 to 20 for the eight loci analyzed (mean of 11 alleles per locus). The mean expected (He) and observed (Ho) heterozygosity were equal to 0.646 and 0.423, respectively. Additionally, the high combined paternity exclusion probability (QC= 0.99579), and the low combined probability of identity (IC = 7.9 x10-5) indicate that markers can be reliable for this kind of analysis. Multilocus outcrossing rates (t ̂_m= 0.957) and single locus outcrossing rates (t ̂_s= 0.848) were high. Biparental inbreeding (t_m-t_s =0,109) ) combined for all families analyzed was also high and significant, sugesting the occurrence of 10.9% of cross-fertilization between related individuals. Paternity correlation was also low (r ̂_p=0,119), with 11.9% of the progeny sired by cross-fertilization with the same pollen donor. On average 10.79% of the progeny analyzed were derived by biparental cross, whereas 84.70% were formed by multi-parental crosses, being related to the degree of half-sibs. Only 4.6% of the seeds were formed by selfing. Paternity was successfully assigned with 95% of confidence to 32% (171) of the seeds analyzed, most likely due to non-sampled candidate pollen donors or because the loci battery could not demonstrated the optimal values for the combined exclusion. The maximum pollen dispersal distance (224 m) corresponded to the length of the orchard. The “big-bang” flowering pattern and the aggregated spatial distribution of adults may have favored short distance pollen dispersal at the germplasm collection of E. dysenterica. Our results show that the E. dysenterica germplasm collection preserves the genetic diversity present in natural populations of southeastern Goiás and can be a reliable approach for maintenance of genetic diversity of the species for the future. / A definição de qualquer programa de melhoramento ou de conservação de recursos genéticos depende, inicialmente, do conhecimento do fluxo gênico, do sistema reprodutivo e da variabilidade genética existente nas populações. Nesse sentido, as coleções de germoplasma podem funcionar como um método de conservação in vivo e ex situ, em que amostras da variabilidade genética de determinada espécie é conservada fora do habitat da espécie. O objetivo geral desse estudo foi avaliar o fluxo via pólen de uma geração, o sistema reprodutivo e caracterizar molecularmente os indivíduos que compõem a coleção de germoplasma in vivo e ex situ de Eugenia dysenterica DC., mantida pela Escola de Agronomia e Engenharia de Alimentos da Universidade Federal de Goiás. Para tanto, foram coletadas folhas das 404 árvores e frutos de 23 árvores (matrizes) que compõem a coleção de germoplasma. Para a obtenção dos genótipos das árvores e das progênies foram utilizados oito locos microssatélites, quatro desenvolvidos para espécie e os outros quatro desenvolvidos para Eucalyptus ssp. e transferidos para E. dysenterica. Com base nos genótipos foram realizadas as análises descritivas de variabilidade genética, testes de paternidade, distância de dispersão de pólen e taxa de fecundação cruzada para todas as progênies. Para os oito locos analisados, o número de alelos foi igual a 88, variando entre 4 e 20 com uma média igual a 11 alelos por loco. Os valores médios de heterosigozidade esperada (He) e observada (Ho) foram iguais a 0,646 e 0,423. Avaliada a variabilidade genética nas duas gerações foi possível concluir que a coleção de germoplasma de E. dysenterica está preservando bem a diversidade genética oriunda das populações naturais da região sudeste do Estado de Goiás. Adicionalmente, a probabilidade de exclusão combinada (QC) foi igual a 0,99579 e a probabilidade de identidade combinada (IC) foi igual a 7,9x10-5. As taxas de cruzamento multiloco (t ̂_m) e uniloco (t ̂_s) foram altas e iguais a 0,957 e 0,848, respectivamente. A diferença da taxa de cruzamento multiloco e uniloco (t_m-t_s ) combinada para todas as famílias analisadas também foi positiva e significativa, indicando a ocorrência de 10,9% (t_m-t_s=0,109) de fecundação cruzada entre indivíduos aparentados. A correlação de paternidade foi baixa (r ̂_p=0,119) sugerindo que 11,9% dos indivíduos das progênies são filhos do mesmo doador de pólen. Em média 10,79% das progênies analisadas foram originadas por cruzamentos biparentais, sendo aparentados no grau de irmãos germanos, 84,70% foi formada por cruzamentos, sendo aparentados no grau de meios-irmãos e somente 4,6% das sementes foram formadas por autofecundação. Na análise de paternidade, apenas 32% (171) das sementes tiveram seus doadores de pólen atribuídos para um nível de confiança de 95%, o que pode ser explicado por três fatores: a presença de indivíduos juvenis não amostrados; a presença de outros indivíduos de E. dysenterica em outras estações experimentais próximas a coleção de germoplasma; ou pela bateria de locos, que não apresentou os valores considerados ótimos para a probabilidade de exclusão combinada. O efeito da floração “big-bang” e a distribuiçao agregada dos indivíduos adultos torna predominante os eventos de fecundação cruzada em curtas distâncias na coleção de germoplasma de E. dysenterica. O alcance máximo de dispersão de pólen foi de 224 m, esse valor abrange quase toda a área experimental da coleção de germoplasma.
66

Flowering time and natural selection in <em>Arabidopsis lyrata</em>

Riihimäki, M.-A. (Mona-Anitta) 12 August 2005 (has links)
Abstract Arabidopsis lyrata is a close outcrossing relative of Arabidopsis thaliana, the model organism of plant physiology and molecular biology. I studied variation in flowering time and the factors shaping the variation within and between A. lyrata populations in different environments. The role of the two important proximate factors determining flowering time, day length and temperature, were studied in climate chambers. The southern A. lyrata populations were found to flower in high frequency and quicker than northern A. lyrata populations in all studied environments, but the reaction of northern populations on long day length was found to be stronger than that of southern populations. Differences in vernalization requirement between A. lyrata populations were found in outdoor common garden, but in the climate chambers the results of vernalization experiments were not consistent. Strength and direction of selection on flowering time and other life history traits were studied in alpine and lowland A. lyrata populations in Scandinavia. Differences in selection were found both between populations and between years. Grazing sheep caused high levels of damage in inflorescences in the alpine population. In the lowland population there was less herbivory, caused by insects and hares. The difference in selection on flowering traits in the two study populations might be partly caused by selective grazing. Completely outcrossing mating system in A. lyrata is due to well developed self-incompatibility system. However, biparental inbreeding is likely to exist in natural populations and it may lead to spatial structuring of genetic variation within populations. I studied the effects of biparental inbreeding on components of fitness in A. lyrata in three different environments. I found inbreeding depression after sib-mating to be substantial. Stressful environment reduced the overall performance of the plants, but had no effect on the magnitude of inbreeding depression. A literature survey indicates that the observed levels of inbreeding depression in self-incompatible A. lyrata were higher than those of self-compatible species. This suggests that self-compatible species have purged some of their genetic load. The genetic basis of flowering time variation in A. lyrata can be further studied by using A. thaliana molecular tools.
67

Evolução em Cycloramphidae : diversidade e especiação na Mata Atlântica brasileira /

Sá, Fábio Perin de. January 2019 (has links)
Orientador: Célio Fernando Baptista Haddad / Resumo: As forças de seleção natural e sexual atuam sobre os indivíduos e podem os levar ao isolamento reprodutivo. O acúmulo de modificações evolutivas pode levar ao surgimento de novas entidades. Espécie é unidade basal em biologia; assim, com sua exuberante biodiversidade, a Mata Atlântica é uma floresta neotropical fundamental para estudos de processos evolutivos em anfíbios anuros. Reunindo os gêneros Cycloramphus, Thoropa e Zachaenus, a família Cycloramphidae agrupa espécies de anuros saxícolas e terrestres, todas endêmicas da Mata Atlântica brasileira. Pelos seus hábitos especializados de vida e reprodução, os cicloramfídeos formam um grupo atrativo para estudos evolutivos. Na presente tese são apresentados quatro capítulos que abordam três escalas distintas da evolução: a diversificação entre espécies, populações e indivíduos. São abordados: (1) a filogenia molecular multilocus de Cycloramphus-Zachaenus, demonstrando que a evolução da terrestrialidade no clado se correlaciona com o dimorfismo sexual em tamanho; (2) a diversificação fenotípica associada a diversificações genéticas em populações de C. boraceiensis e C. dubius, demonstrando que estas duas espécies-irmãs saxícolas apresentam zona de contato e hibridação; (3) o sistema de acasalamento promíscuo e as relações sociais em C. boraceiensis, demonstrando que tamanho das fêmeas e dos machos e parentesco genético influenciam a formação dos casais; e (4) o sistema de acasalamento poligínico com fidelidade na espécie saxíco... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Natural and sexual selection forces act on individuals and may lead to reproductive isolation. The increase in evolutionary modifications may lead to the emergence of new entities. Species is the basal unity in biology; thus, with its exuberant biodiversity, the Atlantic rainforest is a fundamental Neotropical forest for studies of evolutionary processes in anuran amphibians. Comprising the genera Cycloramphus, Thoropa, and Zachaenus, the family Cycloramphidae gathers saxicolous and terrestrial anuran species, all endemic to the Brazilian Atlantic rainforest. Because of their specialized life and reproductive habits, cycloramphids are an attractive group for evolutionary studies. In the present thesis we show four chapters that address three distinct scales of evolution: the diversification among species, populations, and individuals. We goaled: (1) the multilocus molecular phylogeny of Cycloramphus-Zachaenus, demonstrating that the evolution of terrestriality in the clade is correlated with the sexual size dimorphism; (2) the phenotypic diversification associated with the genetic diversifications in populations of C. boraceiensis and C. dubius, demonstrating that these two saxicolous sister species show a contact zone and hybridization; (3) the promiscuous mating system and the social relations in C. boraceiensis, demonstrating that female and male sizes, and mate relatedness influence pair formation; and (4) the polygynic mating system with fidelity in the saxicolous specie... (Complete abstract click electronic access below) / Doutor
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Behavioral Ecology and Conservation Genetics of the Sister Islands Rock Iguana

Moss, Jeanette Blair 03 May 2019 (has links)
Insular fauna face disproportionate risks of extinction owing to direct human perturbation and intrinsic factors that are enhanced at small population sizes. Currently, our understanding of the processes that promote long-term persistence of naturally small populations and the cryptic processes that may contribute to accelerating their decline is limited by lack of empirical investigations across the range of natural conditions. Implementing effective protections for rare and understudied taxa requires the identification and examination of factors that limit recruitment at critical life stages. Predicting population health outcomes of future perturbations further necessitates an understanding a taxon’s behavioral ecology. Finally, cryptic threats to viability, such as inbreeding depression, must be investigated with an appreciation for taxon-specific life history, as these attributes can alter the context in which severe fitness reductions are expressed. In this project I enlist integrative and cross-disciplinary approaches to study the behavioral ecology and conservation genetics of a critically endangered West Indian Rock Iguana, Cyclura nubila caymanensis, on Little Cayman Island. I demonstrate how coastal communal nesting areas, a critical limiting resource on the island, serve a diverse population demographic and contribute to significantly enhanced nesting outcomes. These data emphasize the importance of expanding protections for major sites, as aggregative nesting appears to be perpetuated by both habitat suitability and adaptive fitness benefits. I next evaluate the possibility of evolved inbreeding avoidance strategies, including natal dispersal, non-assortative mate choice, and genetic bet-hedging. I conclude that the contribution of pre-reproductive dispersal to inbreeding avoidance likely outweighs that of active mate choice. Importantly, observed patterns of siring success imply constrained female choice and sexual conflict over genetic mating outcomes – a pattern that may extend to many territorial, male-driven mating systems and therefore should be an important consideration in genetic management. Finally, I investigate age-dependent inbreeding effects and the degree to which inbreeding depression may limit recruitment to the breeding population. I fail to reveal significant correlations of multi-locus heterozygosity with hatchling fitness; however, negative effects of parental inbreeding on fecundity and hatching success imply fitness consequences of inbreeding depression could be felt at other life stages.
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Cis-regulatory variation and divergence in Capsella

Steige, Kim A. January 2016 (has links)
Cis-regulatory changes in e.g. promoters or enhancers that affect the expression of a linked focal gene have long been thought to be important for adaptation. In this thesis, I investigate the selective importance and genomic correlates of cis-regulatory variation and divergence in the genus Capsella, using massively parallel sequencing data. This genus provides an opportunity to investigate cis-regulatory changes in response to polyploidization and mating system shifts, as it harbors three diploid species, the outcrosser Capsella grandiflora and the selfers Capsella orientalis and Capsella rubella, as well as the tetraploid Capsella bursa-pastoris. We first identify cis-regulatory changes associated with adaptive floral evolution in connection with the recent switch to self-fertilization in C. rubella and show that cis-regulatory changes between C. rubella and its outcrossing close relative C. grandiflora are associated with differences in transposable element content. Second, we show that variation in positive and purifying selection is important for the distribution of cis-regulatory variation across the genome of C. grandiflora. Interestingly, the presence of polymorphic transposable elements is strongly associated with cis-regulatory variation in C. grandiflora. Third, we show that the tetraploid C. bursa-pastoris is of hybrid origin and investigate the contribution of both parental species to gene expression. We show that gene expression in the tetraploid is partly explained by cis-regulatory divergence between the parental species. Nonetheless, within C. bursa-pastoris there is a great deal of variation in homeolog expression. In summary, this thesis explores the role of cis-regulatory changes for adaptive morphological changes in connection to a shift in mating system, the role of cis-regulatory divergence between progenitor species for an allopolyploid as well as the impact of positive and purifying selection on cis-regulatory variation within a species.
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Biologie de la conservation de la gorgone rouge de Méditerranée, Paramuricea clavata, dans le contexte actuel du changement climatique

Mokhtar-Jamai, Kenza 23 September 2011 (has links)
La gorgone rouge, Paramuricea clavata (Cnidaire, Octocoralliaire), est une espèce sessile, longévive à faible croissance dont les populations présentent une lente dynamique. Cette espèce est caractérisée par une phase larvaire pélagique qui représente l’unique phase de dispersion potentielle au cours du cycle de vie de cette espèce. P. clavata est une espèce clé des assemblages à coralligène de Méditerranée, qui subit les effets combinés des activités de plongée sous-marine et du changement climatique. Dans ce contexte, il était donc fondamental d’approfondir les connaissances sur les traits d’histoire de vie, la biologie et l’écologie de cette espèce. L’objectif de ce travail était d’étudier, à l’aide d’une approche génétique, les facteurs biologiques et écologiques clés qui devraient être importants pour la réponse de l’espèce aux changements environnementaux. Parmi ces facteurs, la dispersion larvaire joue un rôle fondamental dans la dynamique et la connectivité des populations marines. Dans le contexte actuel des fortes pressions anthropiques, la compréhension des degrés de connectivité entre les populations est primordiale pour évaluer le devenir des populations, face au changement climatique, et pour mettre en place des plans de conservation et des réseaux d’aires marines protégées. / The red gorgonian, Paramuricea clavata (Cnidaria, Octocorallia), is a sessile, long-lived and slow growing species which displays slow population dynamics. This species is characterized by a pelagic larval phase that represents the sole potential phase of dispersal during the life cycle of this species. P. clavata is a key species of coralligenous assemblages of the Mediterranean Sea which undergoes the combined effects of diving activities and climate change. In this context, extending the knowledge about life history traits, biology and ecology of the red gorgonian was of fundamental importance. Using a genetic approach, the goal of this work was to study some key biological and ecological factors which should be important for the response of this species to environmental changes. Among these factors, larval dispersal plays a major role in driving marine population dynamics and connectivity. In the current context of strong anthropic pressures, understanding the level of population connectivity is primordial to evaluate population outcome, facing climate change, and to develop conservation plans as well as to design marine reservenetworks.

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