Mitochondrial dynamics in plant male gametophyte visualized by fluorescent live imaging
Mitochondrial dynamics in plant male gametophyte visualized by fluorescent live imaging
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DOI：
10.1093/pcp/pcn084
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发表时间：
2008-07-01
影响因子：
4.9
通讯作者：
Sakamoto, Wataru
中科院分区：
文献类型：
--
作者：
Matsushima, Ryo;Hamamura, Yuki;Sakamoto, Wataru
活细胞细胞器的可视化是研究其动态行为的有力方法。在这里，我们试图可视化由一个营养细胞（VC）和两个精子细胞（SCs）组成的被子植物雄性配子体（拟南芥花粉粒）的线粒体。将线粒体靶向荧光蛋白与VC或sc特异性表达相结合，使我们能够观察到线粒体在各自细胞类型中的精确数量和动态行为。此外，双受精过程中SC线粒体的实时成像证实了先前在其他物种中通过电子显微镜证实的观察结果，即精子线粒体进入卵子和中心细胞。我们还试图可视化由于线粒体分裂缺陷而被拉长的突变线粒体。该突变型确实在杂合的F-1植株的VC线粒体中检测到，表明雄性配子体线粒体分裂活跃。最后，我们进行了突变体筛选，并分离出一个假定的线粒体蛋白转运突变体，其表型仅在单倍体细胞中可检测到。这项工作中提出的转基因材料不仅对实时成像有用，而且对通过突变分析研究线粒体功能也很有用。
Visualization of organelles in living cells is a powerful method for studying their dynamic behavior. Here we attempted to visualize mitochondria in angiosperm male gametophyte (pollen grain from Arabidopsis thaliana) that are composed of one vegetative cell (VC) and two sperm cells (SCs). Combination of mitochondria-targeted fluorescent proteins with VC- or SC-specific expression allowed us to observe the precise number and dynamic behavior of mitochondria in the respective cell types. Furthermore, live imaging of SC mitochondria during double fertilization confirmed previous observations, demonstrated by electron microscopy in other species, that sperm mitochondria enter into the egg and central cells. We also attempted to visualize mutant mitochondria that were elongated due to a defect in mitochondrial division. This mutant phenotype was indeed detectable in VC mitochondria of a heterozygous F-1 plant, suggesting active mitochondrial division in male gametophyte. Finally, we performed mutant screening and isolated a putative mitochondrial protein transport mutant whose phenotype was detectable only in haploid cells. The transgenic materials presented in this work are useful not only for live imaging but also for studying mitochondrial functions by mutant analysis.