U7 small nuclear RNA （snRNA） sequences have been described only for a handful of animal species in the past. Here we describe a computational search for functional U7 snRNA genes throughout vertebrates including the...U7 small nuclear RNA （snRNA） sequences have been described only for a handful of animal species in the past. Here we describe a computational search for functional U7 snRNA genes throughout vertebrates including the upstream sequence elements characteristic for snRNAs transcribed by polymerase Ⅱ. Based on the results of this search, we discuss the high variability of U7 snRNAs in both sequence and structure, and report on an attempt to find U7 snRNA sequences in basal deuterostomes and non-drosophilids insect genomes based on a combination of sequence, structure, and promoter features. Due to the extremely short sequence and the high variability in both sequence and structure, no unambiguous candidates were found. These results cast doubt on putative U7 homologs in even more distant organisms that are reported in the most recent release of the Rfam database.展开更多
We propose a program for a computational analysis,based on large scale datasets,of deep conceptual and formal structures,representing the mechanisms of historical transformations in different domains ranging from biol...We propose a program for a computational analysis,based on large scale datasets,of deep conceptual and formal structures,representing the mechanisms of historical transformations in different domains ranging from biological to social,cultural,and knowledge systems.We conceptualize such systems as consisting of complex multi-layer networks.Structural properties of such networks may explain the spreading of innovations.Temporal relations between the dynamics of interacting networks may help to identify causalities.Complex systems may show path and context dependencies.We illustrate our approach by case studies from all those types of systems.展开更多
文摘U7 small nuclear RNA （snRNA） sequences have been described only for a handful of animal species in the past. Here we describe a computational search for functional U7 snRNA genes throughout vertebrates including the upstream sequence elements characteristic for snRNAs transcribed by polymerase Ⅱ. Based on the results of this search, we discuss the high variability of U7 snRNAs in both sequence and structure, and report on an attempt to find U7 snRNA sequences in basal deuterostomes and non-drosophilids insect genomes based on a combination of sequence, structure, and promoter features. Due to the extremely short sequence and the high variability in both sequence and structure, no unambiguous candidates were found. These results cast doubt on putative U7 homologs in even more distant organisms that are reported in the most recent release of the Rfam database.
文摘We propose a program for a computational analysis,based on large scale datasets,of deep conceptual and formal structures,representing the mechanisms of historical transformations in different domains ranging from biological to social,cultural,and knowledge systems.We conceptualize such systems as consisting of complex multi-layer networks.Structural properties of such networks may explain the spreading of innovations.Temporal relations between the dynamics of interacting networks may help to identify causalities.Complex systems may show path and context dependencies.We illustrate our approach by case studies from all those types of systems.
