The PIWI-interacting RNA pathway, one of the major eukaryotic small RNA silencing pathways, is a genome surveillance system that silences selfish genes in animal gonads. piRNAs guide PIWI protein to target genes through Watson–Crick RNA–RNA base-parings. Loss of piRNA function causes genome instability, inducing failure in gametogenesis and infertility. Studies using fruit flies and mice as key experimental models have resulted in tremendous progress in understanding the mechanism underlying the piRNA pathway. Recent work using cultured silkworm germline cells has also (...) expanded our knowledge of piRNA biogenesis in particular, since these silkworm cells are the only cells of germline origin that can be cultured. In this review, we describe elucidation of the piRNA pathway using cultured silkworm cells as an experimental model by focusing on recent work in biochemistry and structural biology. Earlier studies that made important contributions to the field are also described. PIWI-interacting RNAs are germline-enriched small RNAs that silence transposons to maintain genome integrity. Recently, cultured silkworm germline cells such as BmN4 made great contributions to understand the mechanism underlying piRNA biogenesis in particular. In this review, we highlight the recent progress in biochemical and structural biology. (shrink)

Der Artikel untersucht das Konzept des „Neuen Menschen“ am Beispiel der Ästhetik und Anthropologie des Bauhauses. Maßgeblich ist dafür das Verhältnis von Körper und Technik, wie es auf der Bauhausbühne für den Tanz insbesondere durch Oskar Schlemmer konzipiert, bildlich und tänzerisch dargestellt und in seinem Unterricht systematisch ausgebaut wurde. Die Idee von „Mensch und Kunstfigur“, die Relation von Mensch, Material, Umraum und Praxis wird modellhaft umgesetzt in Schlemmers „Triadischem Ballett“ und den „Bauhaustänzen“. Ausgehend von diesem Beispiel aus der Avantgarde des (...) 20. Jahrhunderts wird in dem Artikel gefragt, wie sich diese Idee des Menschen als „Gefüge“ von Körper, Technik, Umwelt im zeitgenössischen Tanz weiterentwickelt: am Beispiel von Choreographien von Gerhard Bohner („Im goldenen Schnitt“), Ola Maciejewska („Bombyx Mori“) und William Forsythe („Black Flags“). (shrink)

Japanese agricultural scientist Toyama Kametaro's report about the Mendelian inheritance of silkworm cocoon color in Studies on the Hybridology of Insects (1906) spurred changes in Japanese silk production and thrust Toyama and his work into a scholarly exchange with American entomologist Vernon Kellogg. Toyama's work, based on research conducted in Japan and Siam, came under international scrutiny at a time when analyses of inheritance flourished after the "rediscovery" of Mendel's laws of heredity in 1900. The hybrid silkworm studies in Asia (...) attracted the attention of Kellogg, who was concerned with how experimental biology would be used to study the causes of natural selection. He challenged Toyama's conclusions that Mendelism alone could explain the inheritance patterns of silkworm characters such as cocoon color because they had been subject to hundreds of years of artificial selection, or breeding. This examination of the intersection of Japanese sericulture and American entomology probes how practical differences in scientific interests, societal responsibilities, and silkworm materiality were negotiated throughout the processes of legitimating Mendelian genetics on opposite sides of the Pacific. The ways in which Toyama and Kellogg assigned importance to certain silkworm properties show how conflicting intellectual orientations arose in studies of the same organism. Contestation about Mendelism took place not just on a theoretical level, but the debate was fashioned through each scientist's rationale about the categorization of silkworm breeds and races and what counted as "natural." This further mediated the acceptability of the silkworm not as an experimental organism, but as an appropriately "natural" insect with which to demonstrate laws of inheritance. All these shed light on the challenges that came along with the use of agricultural animals to convincingly articulate new biological principles. (shrink)