• The zygnematophycean algae occupy an important phylogenetic position as the closest living relatives of land plants. Reverse genetics is quite useful for dissecting the functions of genes. However, this strategy requires genetic transformation, and there are only a few reports of successful transformation in zygnematophycean algae.
• Here, we established a simple and highly efficient transformation technique for the unicellular zygnematophycean alga Closterium peracerosum-strigosum-littorale complex using a square electric pulse-generating electroporator without the need for cell wall removal.
• Using this method, the transformation efficiency increased > 100-fold compared with our previous study using particle bombardment. We also succeeded in performing CRISPR/Cas9-based gene knockout using this new method.
• Our method requires only small amounts of labor, time and incubator space. Moreover, our technique could also be utilized to transform other charophycean algae with available genome information by optimizing the electric pulse conditions.

中文翻译：

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方脉冲电穿孔对模型接合藻类藻类Closterium peracerosum-strigosum-littorale复合物的高效转化

• 接合藻类作为陆地植物的近亲，在系统发育中占有重要的地位。反向遗传学对于剖析基因的功能非常有用。然而，这种策略需要进行基因改造，在接合藻类中成功转化的报道很少。
• 在这里，我们使用方形电脉冲产生电穿孔器为单细胞接合藻类藻类Closterium peracerosum-strigosum-littorale复合物建立了一种简单高效的转化技术，无需去除细胞壁。
• 使用这种方法，与我们之前使用粒子轰击的研究相比，转化效率提高了 > 100 倍。我们还使用这种新方法成功地进行了基于 CRISPR/Cas9 的基因敲除。
• 我们的方法只需要少量的劳动力、时间和孵化器空间。此外，我们的技术还可以通过优化电脉冲条件，利用可用的基因组信息来转化其他轮藻。