Poetsch B, Schreckenbach T, Werenskiold A K
Max-Planck-Institut für Biochemie, Martinsried, Federal Republic of Germany.
Eur J Biochem. 1989 Jan 15;179(1):141-6. doi: 10.1111/j.1432-1033.1989.tb14531.x.
Photo-induced fruiting-body formation of the slime mold Physarum polycephalum can be divided into two stages. The first stage (I) starts with the beginning of illumination (0 h) and ends with the formation of nodules (12 h). The second stage (II) is characterized by culmination, sporangiophore formation and melanization of sporangiophore heads (13-17 h). We investigated the expression of actin, alpha- and beta-tubulin during this differentiation process using Northern blot analysis and run-off transcription in isolated nuclei. Whereas actin mRNA is irreversibly lost during stage I, we observed two peaks in mRNA concentration for alpha-tubulin and one peak for that of beta-tubulin during stage I and a coordinated alpha/beta-tubulin mRNA induction during stage II. Stage II induction appears to be related to a presporangial mitosis. Transcriptional activity of the three genes studied shows two maxima, namely one in the middle of stage I and the other at the end of stage II. Our data suggest that the expression of the three cytoskeletal proteins investigated follows a distinct temporal pattern comprising changes in both mRNA synthesis and decay. We also propose a novel function of tubulin in Physarum which is not related to mitosis.
多头绒泡菌光诱导子实体形成可分为两个阶段。第一阶段（I）从光照开始（0小时）起，到结节形成（12小时）结束。第二阶段（II）的特征是 culmination、孢囊梗形成以及孢囊梗头部黑化（13 - 17小时）。我们使用Northern印迹分析和分离细胞核中的径流转录来研究肌动蛋白、α-和β-微管蛋白在该分化过程中的表达。在第一阶段，肌动蛋白mRNA不可逆地丢失，而我们观察到α-微管蛋白的mRNA浓度出现两个峰值，β-微管蛋白的mRNA浓度在第一阶段出现一个峰值，并且在第二阶段α/β-微管蛋白mRNA协同诱导。第二阶段的诱导似乎与前孢子有丝分裂有关。所研究的三个基因的转录活性显示出两个最大值，即在第一阶段中期一个，在第二阶段末期另一个。我们的数据表明，所研究的三种细胞骨架蛋白的表达遵循一种独特的时间模式，包括mRNA合成和降解的变化。我们还提出了微管蛋白在绒泡菌中的一种与有丝分裂无关的新功能。 （注：“culmination”这个词在生物学专业语境中可能有特定含义，但仅从文本看暂不太明确其准确对应中文的专业术语，这里保留英文未翻译）
