Immersing anemones in calcium-free seawater disorganizes hair bundle mechanoreceptors on tentacles of sea anemones while causing a loss of vibration sensitivity. Remarkably, anemone hair bundles recover after being returned to calcium-containing seawater. Reorganization of actin in stereocilia likely follows during the recovery of normal morphology of hair bundles after such immersion. Previous studies have reported that Rho G-proteins are located in the stereocilia of hair bundles in sea anemones where they participate in polymerizing actin in stereocilia upon activation of specific chemoreceptors. We here find that immersing anemones in calcium-free seawater significantly reduces the abundance of hair bundles. A partial recovery of abundance of hair bundles occurs within 3 h post-immersion, but a full recovery of abundance does not occur even 6 h after specimens are returned to calcium-containing seawater. Anemones recovering from immersion in calcium-free seawater feature hair bundles that are significantly wider at their tips than in controls. The hair bundles subsequently narrow at their tips, becoming comparable to those of untreated controls within 6 h. Stereocilia of hair bundles are significantly longer in experimental animals than in controls at 2 h of recovery before shortening to lengths comparable to untreated controls at 6 h. In the presence of Rho inhibitors, the recovery in abundance of hair bundles through 6 h is delayed or inhibited. Likewise, in the presence of Rho inhibitors, stereocilia fail to significantly elongate within 2 h of recovery. These data suggest that Rho G-proteins participate in the normal recovery of abundance and recovery of normal morphology of experimentally damaged hair bundle mechanoreceptors.

中文翻译：

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Rho家族G蛋白是恢复海葵Nematostella vectensis中受损的发束机械感受器所必需的。

将海葵浸入无钙海水中会使海葵触角上的发束机械感受器混乱，同时导致振动敏感性降低。值得注意的是，海葵发束在返回到含钙的海水后会恢复。浸没后，发束的正常形态恢复期间，可能会在立体纤毛中发生肌动蛋白重组。先前的研究已经报道，Rho G蛋白位于海葵的发束的立体纤毛中，在特定化学感受器激活后，它们参与立体纤毛中的聚合肌动蛋白。我们在这里发现，将海葵浸入无钙海水中会显着减少发束的丰度。浸没后3小时内发束恢复丰满，但即使将标本放回含钙的海水中6小时也无法完全恢复到丰度。从浸泡在无钙海水中恢复的海葵，其发束的顶端比对照组的发束要宽得多。随后，发束在其尖端变窄，在6小时内可与未处理的对照组相比。在恢复2小时后，实验动物的发束的立体定向明显长于对照组，而在6小时之前缩短到与未处理的对照组相当的长度。在Rho抑制剂的存在下，到6 h大量发束的恢复被延迟或抑制。同样，在存在Rho抑制剂的情况下，立体纤毛在恢复后2小时内也无法显着延长。