caa a22 4500 475768426 CHVBK 20180406123613.0 cr unu---uuuuu 170329e20001001xx s 000 0 eng 10.1007/s004270000100 doi (NATIONALLICENCE)springer-10.1007/s004270000100 Programmed cell death triggered by insect steroid hormone, 20-hydroxyecdysone, in the anterior silk gland of the silkworm, Bombyx mori [Elektronische Daten] [J. Terashima, Noriko Yasuhara, Masafumi Iwami, Sho Sakurai, S. Sakurai] Abstract : Silk gland is a larval specific tissue of lepidopteran insects and begins to degenerate shortly before pupation. Programmed cell death (PCD) of the anterior silk gland of Bombyx mori last instar larvae was studied in vivo and in vitro, focusing on the effects of 20- hydroxyecdysone (20E). The glands began to exhibit signs of PCD in vivo 2 days after gut purge and comp-leted PCD by 48 h. In vitro, 20E prematurely induced PCD, and its completion took 144 h (6 days). An oligo-nucleosomal ladder pattern was observed in DNA extracted at the end of PCD. Caspase 3 inhibitor inhibited attainment of full PCD, but it did not block chromatin condensation as revealed by acridine orange staining. α-Amanitin inhibited the PCD induced by 20E in vitro if added to the culture in the first 8 h. Similarly, cycloheximide and emetine completely blocked PCD when applied in the first 18 h of culture with 20E. These results indicate that 20E-stimulated transcription and protein synthesis for PCD are completed in 8 h and 18 h, respectively. Nevertheless, withdrawal of 20E from the medium at different times showed that 20E must be present in vitro for 42 h to elicit full PCD. Current results indicate that the effects of 20E on the progression of PCD are mediated by two distinct processes - one through nuclear hormone receptors, and the other independent from de novo gene expression. Springer-Verlag Berlin Heidelberg, 2000 Key words Ecdysteroid nationallicence Nuclear condensation nationallicence DNA fragmentation nationallicence α-amanitin nationallicence Cycloheximide nationallicence Terashima J. Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan, JP aut Yasuhara Noriko Department of Biology, Faculty of Science, Kanazawa University, Kanazawa 920-1192, Japan e-mail: ssakurai@kenroku.kanazawa-u.ac.jp Tel.: +81-76-2645713, Fax: +81-76-2645977, JP aut Iwami Masafumi Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan, JP aut Sakurai Sho Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan, JP aut Sakurai S. Department of Biology, Faculty of Science, Kanazawa University, Kanazawa 920-1192, Japan e-mail: ssakurai@kenroku.kanazawa-u.ac.jp Tel.: +81-76-2645713, Fax: +81-76-2645977, JP aut https://doi.org/10.1007/s004270000100 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s004270000100 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Terashima J. Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan, JP aut NATIONALLICENCE 700 1- Yasuhara Noriko Department of Biology, Faculty of Science, Kanazawa University, Kanazawa 920-1192, Japan e-mail: ssakurai@kenroku.kanazawa-u.ac.jp Tel.: +81-76-2645713, Fax: +81-76-2645977, JP aut NATIONALLICENCE 700 1- Iwami Masafumi Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan, JP aut NATIONALLICENCE 700 1- Sakurai Sho Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan, JP aut NATIONALLICENCE 700 1- Sakurai S. Department of Biology, Faculty of Science, Kanazawa University, Kanazawa 920-1192, Japan e-mail: ssakurai@kenroku.kanazawa-u.ac.jp Tel.: +81-76-2645713, Fax: +81-76-2645977, JP aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer