The pleiotropic effects of ftn2 and ftn6 mutations in cyanobacterium Synechococcus sp PCC 7942
The pleiotropic effects of ftn2 and ftn6 mutations in cyanobacterium Synechococcus sp PCC 7942
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DOI：
10.1007/s00709-012-0479-2
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发表时间：
2013-08-01
期刊：
影响因子：
2.9
通讯作者：
Koksharova, O. A.
中科院分区：
文献类型：
--
作者：
Gorelova, O. A.;Baulina, O. I.;Koksharova, O. A.
蓝藻聚球藻的两个细胞分裂突变体（Ftn2 和 Ftn6）。使用扫描电子显微镜和透射电子显微镜方法研究了 PCC 7942。这包括负染色和超薄切片分析。鉴定了突变细胞的不同形态和超微结构特征。 Ftn2 和 Ftn6 突变体表现出特别细长的细胞，其特征是与野生型相比，形状显着改变。有不规则的弯曲、弯曲、螺旋化、凸起以及细胞分支。伸长的突变细胞能够在沿着细胞不规则定位的几个分裂位点同时启动胞质分裂。细胞壁刚性受损是这两种突变体的许多细胞的典型特征。突变体的类囊体显示出排列和超微结构的改变。在突变体中经常检测到没有壳和/或没有精确的多面体包装蛋白颗粒的羧基体样结构。然而，就 Ftn2 和 Ftn6 而言，每个切片的平均羧基数分别比野生型少 4 倍和 2 倍。突变细胞中的这些多种形态和超微结构变化表现出由细胞分裂基因 ftn2 和 ftn6 突变诱导的多效性反应。 Ftn2 和 Ftn6 突变体的超微结构异常与其蛋白质组的差异一致。这些结果可以支持 FTN2 和 FTN6 蛋白对于蓝藻细胞分裂和细胞生理学的重要性。
Two cell division mutants (Ftn2 and Ftn6) of the cyanobacterium Synechococcus sp. PCC 7942 were studied using scanning electron microscopy and transmission electron microscopy methods. This included negative staining and ultrathin section analysis. Different morphological and ultrastructural features of mutant cells were identified. Ftn2 and Ftn6 mutants exhibited particularly elongated cells characterized by significantly changed shape in comparison with the wild type. There was irregular bending, curving, spiralization, and bulges as well as cell branching. Elongated mutant cells were able to initiate cytokinesis simultaneously in several division sites which were localized irregularly along the cell. Damaged rigidity of the cell wall was typical of many cells for both mutants. Thylakoids of mutants showed modified arrangement and ultrastructural organization. Carboxysome-like structures without a shell and/or without accurate polyhedral packing protein particles were often detected in the mutants. However, in the case of Ftn2 and Ftn6, the average number of carboxysomes per section was less than in the wild type by a factor of 4 and 2, respectively. These multiple morphological and ultrastructural changes in mutant cells evinced pleiotropic responses which were induced by mutations in cell division genes ftn2 and ftn6. Ultrastructural abnormalities of Ftn2 and Ftn6 mutants were consistent with differences in their proteomes. These results could support the significance of FTN2 and FTN6 proteins for both cyanobacterial cell division and cellular physiology.