1,721,417 research outputs found
Pattern of gene flow across chromosomal hybrid zones in the house mouse Mus musculus domesticus
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Divergent allometric trajectories in gene expression and coexpression produce species differences in sympatrically speciating Midas cichlid fish
Full text linkThe mechanisms of speciation without geographic isolation (i.e., sympatric speciation) remain debated. This is due in part to the fact that the genomic landscape that could promote or hinder species divergence in the presence of gene flow is still largely unknown. However, intensive research is now centered on understanding the genetic architecture of adaptive traits associated with this process as well as how gene expression might affect these traits. Here, using RNA-Seq data, we investigated gene expression of sympatrically speciating benthic and limnetic Neotropical cichlid fishes at two developmental stages. First, we identified groups of coexpressed genes (modules) at each stage. Although there are a few large and well-preserved modules, most of the other modules are not preserved across life stages. Second, we show that later in development more and larger coexpression modules are associated with divergence between benthic and limnetic fish compared with the earlier life stage. This divergence between benthic and limnetic fish in coexpression mirrors divergence in overall expression between benthic and limnetic fish, which is more pronounced later in life. Our results reveal that already at 1-day posthatch benthic and limnetic fish diverge in (co)expression, and that this divergence becomes more substantial when fish are free-swimming but still unlikely to have divergent swimming and feeding habits. More importantly, our study describes how the coexpression of several genes through development, as opposed to individual genes, is associated with benthic–limnetic species differences, and how two morphogenetic trajectories diverge as fish grow older
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
Permanent draft genome sequence of sulfoquinovose-degrading Pseudomonas putida strain SQ1
Full text linkPseudomonas putida SQ1 was isolated for its ability to utilize the plant sugar sulfoquinovose (6-deoxy-6-sulfoglucose) for growth, in order to define its SQ-degradation pathway and the enzymes and genes involved. Here we describe the features of the organism, together with its draft genome sequence and annotation. The draft genome comprises 5,328,888 bp and is predicted to encode 5,824 protein-coding genes; the overall G + C content is 61.58 %. The genome annotation is being used for identification of proteins that might be involved in SQ degradation by peptide fingerprinting-mass spectrometry
Morpohological variation between chromosomal races of Mus musculus domesticus in Central Italy
No full textCapturing the rapidly evolving study of adaptation
Full text linkResearch on the genomics of adaptation is rapidly changing. In the last few decades, progress in this area has been driven by methodological advances, not only in the way increasingly large amounts of molecular data are generated (e.g. with high-throughput sequencing), but also in the way these data are analysed. This includes a growing appreciation and quantitative treatment of covariation among units within the same data type (e.g. genes) or across data types (e.g. genes and phenotypes). The development and adoption of more and more integrative tools have resulted in richer and more interesting empirical work. This special issue – comprising methodological, empirical, and review papers – aims to capture a ‘snapshot’ of this rapidly evolving field. We discuss in particular three important themes in the study of adaptation: the genetic architecture of adaptive variation, protein-coding and regulatory changes, and parallel evolution. We highlight how more traditional key themes in the study of genetic architecture (e.g. the number of loci underlying adaptive traits and the distribution of their effects) are now being complemented by other factors (e.g. how patterns of linkage and number of loci interact to affect the ability to adapt). Similarly, apart from addressing the relative importance of protein-coding and regulatory changes, we now have the tools to look in-depth at specific types of regulatory variation to gain a clearer picture of regulatory networks. Finally, parallel evolution has always been central to the study of adaptation, but now we are often able to address the question of whether – and to what extent – parallelism at the organismal or phenotypic level is matched by parallelism at the genetic level. Perhaps most importantly, we can now determine what mechanisms are driving parallelism (or lack thereof) across levels of biological organization. All these recent methodological developments open up new directions for future studies of adaptive changes across traits, levels of biological organization, demographic contexts and time scales
Arvicanthis e Tatera (Rodentia, Murinae) come indicatori per la determinazione di aree filogeografiche di rilevanza conservazionistica nelle savane dell’Africa orientale
No full textVariations 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
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