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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.
1

Citogenética de 13 espécies de aranhas haploginas pertencentes às famílias Pholcidae, Sicariidae e Scytodidae (Araneomorphae) : evolução cromossômica, sistema cromossômico de determinação sexual e citotaxonomia /

Araujo, Douglas de. January 2007 (has links)
Orientador: Doralice Maria Cella / Banca: Carlos Ribeiro Vilela / Banca: Claudio Juan Bidau / Banca: Francisco de Assis Ganeo de Mello / Banca: Luciana Bolsoni Lourenço / Resumo: Dentre todas as ordens de aracnideos conhecidas taxonomicamente, Araneae e a segunda mais diversa, com numero de especies menor somente em relacao a Acari. Atualmente, 39.725 especies ja foram descritas, sendo que centenas de novas descricoes sao feitas a cada ano em diversas familias de aranhas. O conhecimento citogenetico sobre a ordem restringe-se a analise de 638 especies (ca 2%) do total descrito do ponto de vista taxonomico. Este trabalho tem como objetivos fornecer uma compilacao dos dados citogeneticos existentes para a ordem na literatura ate a presente data, bem como caracterizar e estabelecer as estrategias de diferenciacao cromossomica em 13 especies de aranhas pertencentes ao grupo das haploginas, clado que corresponde a somente 3.257 especies (ca 8%) do total da ordem e a apenas 41 especies (ca 6%) do total cariotipado ate os dias atuais. Aliado a baixa representatividade dos dados cariologicos, outros pontos que fazem das haploginas um grupo interessante para estudos sao a predominancia de cromossomos meta/submetacentricos e de sistemas cromossomicos de determinacao sexual simples e multiplos, muitas vezes incluindo um cromossomo Y, ambas caracteristicas raras entre os outros clados de Araneae. As especies analisadas pertencem a tres familias de haploginas, Pholcidae (Mesabolivar luteus e Micropholcus fauroti), Sicariidae (Loxosceles amazonica, Loxosceles gaucho, Loxosceles hirsuta, Loxosceles intermedia, Loxosceles laeta, Loxosceles puortoi, Loxosceles similis e Sicarius tropicus) e Scytodidae (Scytodes fusca, Scytodes globula e Scytodes itapevi). Em Pholcidae, os resultados ineditos para os dois generos mostraram ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Mesabolivar luteus (Keyserling 1891) and Micropholcus fauroti (Simon 1887) specimens were collected in Ubatuba and Rio Claro, both in the state of São Paulo, Brazil. Mesabolivar luteus showed 2n(.) = 15 = 14 + X and 2n(.) = 16 = 14 + XX in mitotic metaphases and 7II + X in diplotenic cells. During late prophase I, all bivalents presented a ring shape, evidencing two chiasmata per bivalent. In this species, some diplotenic cells appear in pairs, maybe due to specific characteristics of the intercellular bridges. The metaphases II showed n = 7 or n = 8 = 7 + X chromosomes. Micropholcus fauroti evidenced 2n(.) = 17 = 16 + X in spermatogonial metaphases and 8II+X in diplotenic cells, with only one chiasma per bivalent, contrasting with M. luteus. In both species, all chromosomes were metacentrics. The X sexual chromosome was the largest element and appeared as a univalent during meiosis I. These are the first cytogenetical data for the genera Mesabolivar and Micropholcus. Additionally, M. luteus is the first chromosomally analyzed species of the New World clade and the observed diploid number for M. fauroti had not yet been recorded in Pholcidae. / Doutor
2

INFERÊNCIAS EVOLUTIVAS PARA DUAS ESPÉCIES DO GÊNERO Omophoita (COLEOPTERA, CHRYSOMELIDAE): DIFERENCIAÇÃO CARIOTÍPICA E MOLECULAR

Wolski, Michele Andressa Vier 25 February 2014 (has links)
Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2017-10-31T12:38:31Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO michele.pdf: 3067898 bytes, checksum: 4e684091426aed5eb28e585d5db27abb (MD5) / Made available in DSpace on 2017-10-31T12:38:31Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO michele.pdf: 3067898 bytes, checksum: 4e684091426aed5eb28e585d5db27abb (MD5) Previous issue date: 2014-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Alticinae apresenta características cariotípicas muito interessantes quanto a variação do número diplóide, do sistema de determinação sexual e irregularidades meióticas. O número cromossômico mais frequente é de 11 ou 12 pares. As espécies de Oedionychina estudadas citogeneticamente possuem 2n= 22,10II+X+Y com cromossomos sexuais gigantes. No que se refere à posição sistemática existem muitas divergências entre os estudos e problemas de identificação das espécies pertencentes aos vários gêneros. O estudo com técnicas mais refinadas e o mapeamento do DNA r 5S é recente em Coleoptera, e as poucas espécies de Alticinae estudadas mostram a presença de dois ou três pares autossômicos. Assim, este trabalho tem o objetivo de analisar citogeneticamente e propor as estratégias de diferenciação cariotípica para as espécies de Omophoita communis e Omophoita sexnotata. A análise citogenética dos indivíduos de duas populações de O. communis estudadas mostrou a ocorrência de grande variação no número diploide e morfologia cromossômica, sendo possível separá-las em dois citótipos. O citótipo I possui 2n= 22 e o citótipo II 2n= 12, sendo essa variação é descrita pela primeira vez no gênero. Adicionalmente, o estudo da morfologia do edeago mostrou diferenças, indicando um provável padrão de diferenciação das duas espécies. A análise da árvore consenso da reconstrução filogenética também evidencia que os citótipos mostram agrupamentos diferentes e reforçam a hipótese de duas espécies. O estudo do mapeamento do gene DNAr 5S em O. sexnotata evidenciou a presença desse cluster em todos os cromossomos autossômicos, sendo esse padrão de dispersão nunca descrito em Coleoptera. Na literatura, a dispersão dos genes ribossomais está sempre relacionada com a presença de elementos transponíveis. O resultado do sequenciamento dos fragmentos de 5S ribossomal obtidos de cada cromossomo de O. sexnotata resultaram em sequencias similares a RNAr 5S de Drosophila melanogaster, elemento transponível EnSpm, retropseudogene de 5S e microssatélite. Adicionalmente, a analise da estrutura secundaria do RNAr 5S, mostrou que as sequencias obtidas não são funcionais quando comparadas seus percentuais de energia livre em relação ao percentual da sequencia original do RNAr 5S. / Alticinae presents karyotypic characteristics very interesting as the variation of the diploid number, sex determination system and meiotic irregularities. The most frequent chromosome number is 11 or 12 pairs. The species cytogenetically studied Oedionychina have 2n = 22,10 II + X + Y with giant sex chromosomes. In relation to the systematic position there are many divergence between the studies and problems of identification of species belonging to several genera. The study with more refined techniques and rDNA 5s mapping is recent in Coleoptera , and the few Alticinae species studied show the presence of two or three autosomal pairs. Thus, this study aims to analyze cytogenetically and propose strategies for the species karyotype differentiation of Omophoita communis and Omophoita sexnotata. Cytogenetic analysis of individuals of both populations of O. communis showed the existence of a large variation in diploid number and chromosome morphology, being possible to separate them into two cytotypes. Cytotype I presented 2n = 22 and cytotype II 2n = 12, this variation is described for the first time in the genus. Additionally, the study of the morphology of the aedeagus showed differences, indicating a likely pattern of differentiation of the two species. The phylogenetic reconstruction consensus tree analysis also presented that cytotypes show different groupings and reinforce the hypothesis of two species. The 5S rDNA gene mapping of O. sexnotata showed the presence of this cluster in all autosomes, this dispersal pattern was never described in Coleoptera before. In the literature, the dispersion of ribosomal genes is always associated with the presence of transposable elements. The sequencing of 5S rRNA fragments obtained from each chromosome of O. sexnotata resulted in similar to 5S rRNA sequences of Drosophila melanogaster transposable element EnSpm, retropseudogene 5S and microsatellite. Additionally, analysis of the secondary structure of 5S rRNA showed that the sequences obtained are not functional compared their percentage of free energy with the percentage of the original sequence of the 5S rRNA .
3

Citogenética de 13 espécies de aranhas haploginas pertencentes às famílias Pholcidae, Sicariidae e Scytodidae (Araneomorphae): evolução cromossômica, sistema cromossômico de determinação sexual e citotaxonomia

Araujo, Douglas de [UNESP] 27 April 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-04-27Bitstream added on 2014-06-13T21:01:36Z : No. of bitstreams: 1 araujo_d_dr_rcla.pdf: 1858376 bytes, checksum: dbeb43d42be45d0e0d9524437faa5d74 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Dentre todas as ordens de aracnideos conhecidas taxonomicamente, Araneae e a segunda mais diversa, com numero de especies menor somente em relacao a Acari. Atualmente, 39.725 especies ja foram descritas, sendo que centenas de novas descricoes sao feitas a cada ano em diversas familias de aranhas. O conhecimento citogenetico sobre a ordem restringe-se a analise de 638 especies (ca 2%) do total descrito do ponto de vista taxonomico. Este trabalho tem como objetivos fornecer uma compilacao dos dados citogeneticos existentes para a ordem na literatura ate a presente data, bem como caracterizar e estabelecer as estrategias de diferenciacao cromossomica em 13 especies de aranhas pertencentes ao grupo das haploginas, clado que corresponde a somente 3.257 especies (ca 8%) do total da ordem e a apenas 41 especies (ca 6%) do total cariotipado ate os dias atuais. Aliado a baixa representatividade dos dados cariologicos, outros pontos que fazem das haploginas um grupo interessante para estudos sao a predominancia de cromossomos meta/submetacentricos e de sistemas cromossomicos de determinacao sexual simples e multiplos, muitas vezes incluindo um cromossomo Y, ambas caracteristicas raras entre os outros clados de Araneae. As especies analisadas pertencem a tres familias de haploginas, Pholcidae (Mesabolivar luteus e Micropholcus fauroti), Sicariidae (Loxosceles amazonica, Loxosceles gaucho, Loxosceles hirsuta, Loxosceles intermedia, Loxosceles laeta, Loxosceles puortoi, Loxosceles similis e Sicarius tropicus) e Scytodidae (Scytodes fusca, Scytodes globula e Scytodes itapevi). Em Pholcidae, os resultados ineditos para os dois generos mostraram... / Mesabolivar luteus (Keyserling 1891) and Micropholcus fauroti (Simon 1887) specimens were collected in Ubatuba and Rio Claro, both in the state of São Paulo, Brazil. Mesabolivar luteus showed 2n(.) = 15 = 14 + X and 2n(.) = 16 = 14 + XX in mitotic metaphases and 7II + X in diplotenic cells. During late prophase I, all bivalents presented a ring shape, evidencing two chiasmata per bivalent. In this species, some diplotenic cells appear in pairs, maybe due to specific characteristics of the intercellular bridges. The metaphases II showed n = 7 or n = 8 = 7 + X chromosomes. Micropholcus fauroti evidenced 2n(.) = 17 = 16 + X in spermatogonial metaphases and 8II+X in diplotenic cells, with only one chiasma per bivalent, contrasting with M. luteus. In both species, all chromosomes were metacentrics. The X sexual chromosome was the largest element and appeared as a univalent during meiosis I. These are the first cytogenetical data for the genera Mesabolivar and Micropholcus. Additionally, M. luteus is the first chromosomally analyzed species of the New World clade and the observed diploid number for M. fauroti had not yet been recorded in Pholcidae.
4

Analýza diferenciace karyotypů a pohlavních chromozómů u afrických anuálních halančíků rodu Nothobranchius (Teleostei: Nothobranchiidae) / Analysis of karyotype and sex chromosome differentiation in African annual killifish of the genus Nothobranchius (Teleostei: Nothobranchiidae)

Lukšíková, Karolína January 2021 (has links)
Teleost fishes (Teleostei) encompass more than half of the extant vertebrate biodiversity. Their genomes display considerable plasticity and flexibility, going hand in hand with polyploidization events and repetitive DNA dynamics. Teleosts also display a striking diversity in mechanisms of sex determination and differentiation. The aim of the present thesis was to study the mechanisms underlying the karyotype and sex chromosome differentiation through cytogenetic mapping of repetitive DNA (by fluorescence in situ hybridization, FISH) in selected representatives of the African annual killifishes of the genus Nothobranchius (Teleostei: Nothobranchiidae). Nothobranchius spp. evolved a unique adaptation to freshwater temporary water pools whose existence is limited to periods of rainy season in African savannahs. Recent diversification, allopatric speciation in non-overlapping generations and small-sized populations together with known cytogenetics collectively suggest fast dynamics of chromosomal changes in Nothobranchius killifishes. The study took advantage of the availability of i) more populations of several closely related species for analysis and ii) data on specific repetitive DNA composition in selected Nothobranchius genomes as revealed by RepeatExplorer analysis. My work showed considerable...
5

Cytogenetika vybraných skupin paprskoploutvých ryb (Actinopterygii): Evolučně -ekologické aspekty spjaté s dynamikou repetitivních sekvencí a s výskytem polyploidie / Cytogenetics of selected groups of ray-finned fishes (Actinopterygii): Evolutionary-ecological questions associated with the dynamics of repetitive sequences and the occurrence of polyploidy

Sember, Alexandr January 2016 (has links)
Ray-finned fishes (Actinopterygii) exhibit the greatest biodiversity among vertebrates. The vast majority of extant actinopterygian fish species belong to clade Teleostei - a lineage whose significant evolutionary success might have resulted from a teleost specific whole- genome duplication (TSGD) that occurred at the onset of this group, subsequent to its divergence from the rest of actinopterygian lineages. Despite the growing body of sequenced fish genomes and analyses of their transcriptomes, the largest contribution to understanding fish genomes comes from analyses of DNA content and from cytogenetics. Genomes of ray-finned fishes and especially those of Teleostei exhibit vast diversity and rapid dynamics of repetitive DNA sequences whose variability is reflected in a wide range of fish genome sizes and in the dynamics behind karyotype differentiation. Therefore, ray-finned fishes offer a unique opportunity to study genome variability as a driving force underlying morphological and ecological diversification, evolution and adaptation. Particularly, the mapping of repetitive DNA sequences by means of fluorescence in situ hybridization (FISH) has proven to be a very useful and informative approach during the last two decades and contributed greatly to our understanding of the fish genome...

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