Identification and Differential Expression of MicroRNAs during Metamorphosis of the Japanese Flounder (Paralichthys olivaceus)

BACKGROUND: MicroRNAs (miRNAs) are a class of endogenous small non-coding RNAs of 20-25 nucleotides that play a key role in diverse biological processes. Japanese flounder undergo dramatic metamorphosis in their early development. The metamorphosis is characterized by morphological transformation from a bilaterally symmetrical to an asymmetrical body shape concomitant with extensive morphological and physiological remodeling of organs. So far, only a few miRNAs have been identified in fish and there are very few reports about the Japanese flounder miRNA. METHODOLOGY/PRINCIPAL FINDINGS: Solexa sequencing technology was used to perform high throughput sequencing of the small RNA library from the metamorphic period of Japanese flounder. Subsequently, aligning these sequencing data with metazoan known miRNAs, we characterized 140 conserved miRNAs and 57 miRNA: miRNA* pairs from the small RNA library. Among these 57 miRNA: miRNA* pairs, twenty flounder miRNA precursors were amplified from genomic DNA. We also demonstrated evolutionary conservation of Japanese flounder miRNAs and miRNA* in the animal evolution process. Using miRNA microarrays, we identified 66 differentially expressed miRNAs at two metamorphic stages (17 and 29 days post hatching) of Japanese flounder. The results show that miRNAs might play a key role in regulating gene expression during Japanese flounder metamorphosis. CONCLUSIONS/SIGNIFICANCE: We identified a large number of miRNAs during flounder metamorphosis, some of which are differentially expressed at two different metamorphic stages. The study provides an opportunity for further understanding of miRNA function in the regulation of flounder metamorphosis and gives us clues for further studies of the mechanisms of metamorphosis in Japanese flounder

The ‘New’ Heidegger

If discussion of “new” approaches to Martin Heidegger contradicts Heidegger’s own indictment of the passion for “novelty” in philosophy, today’s Black Notebooks scandal reminds us of the ontic problem of new news. Indeed the backwards working evidence of the notebooks kept before, during, and after WWII both vindicates and problematizes his notion of temporality temporalizing from the future -- lapsing into the past -- setting up what is now regarded as patent in the present. Simultaneously, we see that if heretofore many philosophers of technology sought to dismiss engagement with Heidegger’s critique of technology, these critical contributions turn out to bear on current issues of transhumanism, technoscience, time, even death (the overcoming of which we eagerly anticipate). Heidegger’s thinking remains to be appropriated