1,721,109 research outputs found
Conserved but flexible: Genetic control of mimicry in Heliconius butterfly wing patterns
No full textStructural Variants and Speciation: Multiple Processes at Play
No full textResearch on the genomic architecture of speciation has increasingly revealed the importance of structural variants (SVs) that affect the presence, abundance, position, and/or direction of a nucleotide sequence. SVs include large chromosomal rearrangements such as fusion/fissions, inversions and translocations, as well as smaller variants such as duplications, insertions, and deletions (CNVs). Although we have ample evidence that SVs play a key role in speciation, the underlying mechanisms differ depending on the type and length of the SV, as well as the ecological, demographic and historical context. We review predictions and empirical evidence for classic processes such as underdominance due to meiotic aberrations and the coupling effect of recombination suppression before exploring how recent sequencing methodologies illuminate the prevalence and diversity of SVs. We discuss specific properties of SVs and their impact throughout the genome, highlighting that multiple processes are at play, and possibly interacting, in the relationship between SVs and speciation.Fil: Berdan, Emma L.. University Goteborg; SueciaFil: Aubier, Thomas G.. Université Paul Sabatier Toulouse III; ArgentinaFil: Cozzolino, Salvatore. University Of Naples Federico II; ItaliaFil: Faria, Rui. Universidade Do Porto; PortugalFil: Feder, Jeffrey L.. University of Notre Dame; Estados UnidosFil: Giménez, Mabel Dionisia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Provincia de Misiones. Ministerio de Salud de la Provincia de Misiones. Instituto de Genética Humana;Fil: Joron, Mathieu. Universite de Montpellier; FranciaFil: Searle, Jeremy Byron. Cornell University; Estados UnidosFil: Mérot, Claire. Universite de Rennes I; Franci
Convergent Evolution in the Genetic Basis of Mullerian Mimicry in Heliconius Butterflies
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Gene annotation in Heliconius numata colouring the black box
No full textTese de mestrado, Biologia (Biologia Evolutiva e do Desenvolvimento, Universidade de Lisboa, Faculdade de Ciências, 2010O presente projecto teve por objectivo a identificação e anotação de genes que se sabe estarem ligados num arranjo de genes inquebrável por recombinação e que controla a padronização das asas da borboleta Heliconius numata. Este complexo é homologo posicional de complexos em outras espécies de Heliconius, nomeadamente o complexo Yb/Sb em H. melpomene e Cr em H. erato. Este “supergene” é visto como um hotspot de desenvolvimento (sensu Richardson & Brakefield 2003) que controla divergência fenotípica entre espécies próximas e convergência fenotípica entre espécies mais distantes. Em H. numata o supergene sofreu rearranjos genómicos que se pensa estarem correlacionados com a preservação das combinações alélicas necessárias para manter os fenótipos discretos característicos das relações miméticas locais (mimicry rings) que estes organismos estabelecem na natureza. Estes rearranjos podem estar a modificar ou perturbar expressão genica e é, portanto, de extrema importância identificar tais genes bem como compreender a sua estrutura, nomeadamente no que diz respeito a eventuais eventos de clivagem alternativa que possam estar correlacionados com as diferentes raças locais observáveis na natureza. Usando uma combinação de ferramentas bioinformáticas e sequências de transcriptoma de raças com fenótipos diferentes, modelos de genes serão estabelecidos para desenhar primers específicos de modo a amplificar os genes modelizados e testar hipóteses relativamente a diferenças na sua estrutura e distribuição na região de interesse.The present project aims at the identification and annotation of the specific genes known to be in a cluster of tighly linked genes known to control wing patterning in H. numata. This cluster is positionally homologous with cluster in other species of Heliconius, namely Yb/Sb in H. melpomene and Cr in H. erato. This “supergene” is seen as a developmental hotspot (sensu Richardson and Brakefield 2003) controlling both phenotypic divergence between closely related species and convergence between more distantly related species. In H. numata the supergene suffered genomic rearrangements that are thought to be preserving the necessary combination of loci to attain the concrete phenotypes typical in mimicry relations these butterflies establish in nature. These rearrangements may be disturbing or modifying gene expression. Therefore, it is extremely valuable to identify the genes in the genomic region of interest, and address eventual alternative splicing events that could be associated with the different locally adapted races. Using a combination of bioinformatics’ tools and transcriptome sequences from two phenotypically different races, I generated gene models in order to design primers and amplify these genes, testing hypothesis regarding splice variants and validating the models
Gene annotation in Heliconius numata colouring the black box
No full textTese de mestrado, Biologia (Biologia Evolutiva e do Desenvolvimento, Universidade de Lisboa, Faculdade de Ciências, 2010O presente projecto teve por objectivo a identificação e anotação de genes que se sabe estarem ligados num arranjo de genes inquebrável por recombinação e que controla a padronização das asas da borboleta Heliconius numata. Este complexo é homologo posicional de complexos em outras espécies de Heliconius, nomeadamente o complexo Yb/Sb em H. melpomene e Cr em H. erato. Este “supergene” é visto como um hotspot de desenvolvimento (sensu Richardson & Brakefield 2003) que controla divergência fenotípica entre espécies próximas e convergência fenotípica entre espécies mais distantes. Em H. numata o supergene sofreu rearranjos genómicos que se pensa estarem correlacionados com a preservação das combinações alélicas necessárias para manter os fenótipos discretos característicos das relações miméticas locais (mimicry rings) que estes organismos estabelecem na natureza. Estes rearranjos podem estar a modificar ou perturbar expressão genica e é, portanto, de extrema importância identificar tais genes bem como compreender a sua estrutura, nomeadamente no que diz respeito a eventuais eventos de clivagem alternativa que possam estar correlacionados com as diferentes raças locais observáveis na natureza. Usando uma combinação de ferramentas bioinformáticas e sequências de transcriptoma de raças com fenótipos diferentes, modelos de genes serão estabelecidos para desenhar primers específicos de modo a amplificar os genes modelizados e testar hipóteses relativamente a diferenças na sua estrutura e distribuição na região de interesse.The present project aims at the identification and annotation of the specific genes known to be in a cluster of tighly linked genes known to control wing patterning in H. numata. This cluster is positionally homologous with cluster in other species of Heliconius, namely Yb/Sb in H. melpomene and Cr in H. erato. This “supergene” is seen as a developmental hotspot (sensu Richardson and Brakefield 2003) controlling both phenotypic divergence between closely related species and convergence between more distantly related species. In H. numata the supergene suffered genomic rearrangements that are thought to be preserving the necessary combination of loci to attain the concrete phenotypes typical in mimicry relations these butterflies establish in nature. These rearrangements may be disturbing or modifying gene expression. Therefore, it is extremely valuable to identify the genes in the genomic region of interest, and address eventual alternative splicing events that could be associated with the different locally adapted races. Using a combination of bioinformatics’ tools and transcriptome sequences from two phenotypically different races, I generated gene models in order to design primers and amplify these genes, testing hypothesis regarding splice variants and validating the models
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Gene annotation in Heliconius numata colouring the black box
No full textTese de mestrado, Biologia (Biologia Evolutiva e do Desenvolvimento, Universidade de Lisboa, Faculdade de Ciências, 2010O presente projecto teve por objectivo a identificação e anotação de genes que se sabe estarem ligados num arranjo de genes inquebrável por recombinação e que controla a padronização das asas da borboleta Heliconius numata. Este complexo é homologo posicional de complexos em outras espécies de Heliconius, nomeadamente o complexo Yb/Sb em H. melpomene e Cr em H. erato. Este “supergene” é visto como um hotspot de desenvolvimento (sensu Richardson & Brakefield 2003) que controla divergência fenotípica entre espécies próximas e convergência fenotípica entre espécies mais distantes. Em H. numata o supergene sofreu rearranjos genómicos que se pensa estarem correlacionados com a preservação das combinações alélicas necessárias para manter os fenótipos discretos característicos das relações miméticas locais (mimicry rings) que estes organismos estabelecem na natureza. Estes rearranjos podem estar a modificar ou perturbar expressão genica e é, portanto, de extrema importância identificar tais genes bem como compreender a sua estrutura, nomeadamente no que diz respeito a eventuais eventos de clivagem alternativa que possam estar correlacionados com as diferentes raças locais observáveis na natureza. Usando uma combinação de ferramentas bioinformáticas e sequências de transcriptoma de raças com fenótipos diferentes, modelos de genes serão estabelecidos para desenhar primers específicos de modo a amplificar os genes modelizados e testar hipóteses relativamente a diferenças na sua estrutura e distribuição na região de interesse.The present project aims at the identification and annotation of the specific genes known to be in a cluster of tighly linked genes known to control wing patterning in H. numata. This cluster is positionally homologous with cluster in other species of Heliconius, namely Yb/Sb in H. melpomene and Cr in H. erato. This “supergene” is seen as a developmental hotspot (sensu Richardson and Brakefield 2003) controlling both phenotypic divergence between closely related species and convergence between more distantly related species. In H. numata the supergene suffered genomic rearrangements that are thought to be preserving the necessary combination of loci to attain the concrete phenotypes typical in mimicry relations these butterflies establish in nature. These rearrangements may be disturbing or modifying gene expression. Therefore, it is extremely valuable to identify the genes in the genomic region of interest, and address eventual alternative splicing events that could be associated with the different locally adapted races. Using a combination of bioinformatics’ tools and transcriptome sequences from two phenotypically different races, I generated gene models in order to design primers and amplify these genes, testing hypothesis regarding splice variants and validating the models
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