Year: 1971
Type: article
Abstract: Embryos were excised from the seeds of naked barley after 24 hours soaking and were irradiated with 1, 2 and 3 kR of 137Cs γ-rays. Microsomal fractions of these embryos were separated by sucrose gradient centrifugation. Cells of germinating seed embryo have contained both free and bound ribosomes. The ratio of bound to free ribosomes decreased with an increase in dose. There was no significant difference in the yield of microsomal fraction between the nonirradiated and the irradiated except 3 kR. Thus, it was concluded that the yield of free ribosomes increased at the expense of the bound ribosomes by 1 and 2 kR irradiation, and that at 3 kR the degradation of ribosomes per se, in addition to detachment of bound ribosomes from the membranes, occurred. For only irradiated samples, membrane-like substance was found visibly floating in ethanol solution during the process of extracting RNA from the 105, 000 × g supernatant.オオムギ種子を24時間浸漬したのち, 1, 2, 3kRの137Csγ線を照射し, ただちにミクロゾーム画分を分離した。オオムギ種子胚の細胞には遊離型と膜付着型との2種類のリボゾームが存在し, 膜付着型/遊離型の量比は照射線量の増加とともに減少した。ミクロゾーム量の回収率は3kR照射の場合を除いて照射と無照射との間に有意な差異が認められなかった。膜付着型/遊離型の量比の減少は膜付着型リボゾームが照射によって遊離型リボゾームに変化したためと思われる。3kR照射ではこのような変化のほかにリボゾームそのものも分解することが示唆された。照射試料由来の105, 000×g上澄み画分からRNAを抽出する過程でエタノール中に膜様物質の浮遊が可視的に認められた。
Source: RADIOISOTOPES
Authors: Tadao NAITO, Hatsue TOKUDA, Hikoyuki YAMAGUCHI
Institution: The University of Tokyo
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W2073477618