MicroRNA Genes Derived from Repetitive Elements and Expanded by Segmental Duplication Events in Mammalian Genomes

MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression by targeting mRNAs for translation repression or mRNA degradation. Many miRNAs are being discovered and studied, but in most cases their origin, evolution and function remain unclear. Here, we characterized miRNAs derived from repetitive elements and miRNA families expanded by segmental duplication events in the human, rhesus and mouse genomes. We applied a comparative genomics approach combined with identifying miRNA paralogs in segmental duplication pair data in a genome-wide study to identify new homologs of human miRNAs in the rhesus and mouse genomes. Interestingly, using segmental duplication pair data, we provided credible computational evidence that two miRNA genes are located in the pseudoautosomal region of the human Y chromosome. We characterized all the miRNAs whether they were derived from repetitive elements or not and identified significant differences between the repeat-related miRNAs (RrmiRs) and non-repeat-derived miRNAs in (1) their location in protein-coding and intergenic regions in genomes, (2) the minimum free energy of their hairpin structures, and (3) their conservation in vertebrate genomes. We found some lineage-specific RrmiR families and three lineage-specific expansion families, and provided evidence indicating that some RrmiR families formed and expanded during evolutionary segmental duplication events. We also provided computational and experimental evidence for the functions of the conservative RrmiR families in the three species. Together, our results indicate that repetitive elements contribute to the origin of miRNAs, and large segmental duplication events could prompt the expansion of some miRNA families, including RrmiR families. Our study is a valuable contribution to the knowledge of evolution and function of non-coding region in genome

Genome-wide microRNA screening in Nile tilapia reveals pervasive isomiRs’ transcription, sex-biased arm switching and increasing complexity of expression throughout development

MicroRNAs (miRNAs) are key regulators of gene expression in multicellular organisms. The elucidation of miRNA function and evolution depends on the identification and characterization of miRNA repertoire of strategic organisms, as the fast-evolving cichlid fishes. Using RNA-seq and comparative genomics we carried out an in-depth report of miRNAs in Nile tilapia (Oreochromis niloticus), an emergent model organism to investigate evo-devo mechanisms. Five hundred known miRNAs and almost one hundred putative novel vertebrate miRNAs have been identified, many of which seem to be teleost-specific, cichlid-specific or tilapia-specific. Abundant miRNA isoforms (isomiRs) were identified with modifications in both 5p and 3p miRNA transcripts. Changes in arm usage (arm switching) of nine miRNAs were detected in early development, adult stage and even between male and female samples. We found an increasing complexity of miRNA expression during ontogenetic development, revealing a remarkable synchronism between the rate of new miRNAs recruitment and morphological changes. Overall, our results enlarge vertebrate miRNA collection and reveal a notable differential ratio of miRNA arms and isoforms influenced by sex and developmental life stage, providing a better picture of the evolutionary and spatiotemporal dynamics of miRNAs

- Kant-Index, Band 30, Teilband I

Il primo volume della prima edizione critica attendibile del Naturrecht Feyerabend, il manoscritto relativo ad un corso di lezioni sul diritto naturale tenuto da Kant nel 1784. Si tratta dell’unica trascrizione manoscritta da noi posseduta di un corso di Kant sull’argomento, a cura di uno studente di nome appunto Feyerabend. Essa era stata edita nel vol. XXVII, 2,2 dell’edizione dell’Accademia delle opere kantiane (Berlin, 1979), ma con una trascrizione rivelatasi molto imprecisa. L’edizione è prevista in due volumi. L’edizione critica del testo tedesco (rivista sul manoscritto) è accompagnata da note, da indici e concordanze, dall’indicazione dei paralleli con la coeva Fondazione della metafisica dei costumi di Kant.[...

The Kwawu resilient entrepreneurial ecosystems: A complex adaptive systems approach to achieving the Sustainable Development Goals

.CC-BY https://www.taylorfrancis.com/chapters/kwawu-resilient-entrepreneurial-ecosystems-eben-anuwa-amarh-christoph-hinske-nana-kwabena-bamfo-debrah-david-sefa-sheriff-amarh-stephen-nassam/e/10.4324/9781003000365-3

Let the play set come alive: Supporting playful learning through the digital augmentation of a traditional toy environment

The Augmented Knight's Castle (AKC) comprises traditional play figures and scenery embedded with radio frequency identification (RFID) technology to enhance user experience by triggering various forms of audio output. In this paper we present the results of a user study with over 100 children to evaluate the AKC in terms of playful learning, compared with an identical, non-augmented version. Findings suggest that children who played with the AKC remembered facts about the Middle Ages that were presented to them in the form of verbal commentaries, both immediately after the play session as well as in a post-test two months later. 2010 IEEE