Hasan Md Ekramul, Ahamed Saokat, Hassan Mohammad Maksudul, Amin Mohammad Tohidul, Mustary Umme Habiba, Tokumoto Toshinobu
Department of Bioscience, Graduate School of Science and Technology, National University Corporation, Shizuoka University, 836 Ohya, Suruga-Ku, Shizuoka, 422-8529, Japan.
Integrated Bioscience Section, Graduate School of Science and Technology, National University Corporation, Shizuoka University, Ohya 836, Suruga-Ku, Shizuoka, 422-8529, Japan.
Fish Physiol Biochem. 2025 Aug 29;51(5):152. doi: 10.1007/s10695-025-01563-2.
In our previous study, we generated a membrane-type progesterone receptor γ (paqr5b) knockout zebrafish line. Knocking out paqr5b by genome editing resulted in the loss of neurons in the olfactory rosette (OR). These findings indicated that Paqr5b plays an essential role in the formation of olfactory neurons. In this study, we investigated the extent to which paqr5b fish lacking olfactory neurons retain their sense of smell. We used a reported tank for zebrafish olfactory analysis with a dividing plate in the middle. The tank was divided into three zones: the right zone, where test substances were added; the neutral zone; and the left zone. The fish were released into the neutral zone at the beginning of each test, the chemical was added to the corner of the right zone, and a 3-min video was taken to track the movements of the fish. The video was then played back, and the time spent in the three zones was counted manually. Both male and female paqr5b and paqr5b zebrafish were separately analyzed for time spent in the three zones after exposure to ATP, cadaverine, and the pheromone 17α,20β-dihydroxy-4-pregnen-3-one (DHP). Both male and female paqr5b zebrafish were strongly attracted to ATP and stayed in the right zone for approximately 2 min (67%). In addition, paqr5b zebrafish avoided cadaverine and stayed longer in the left zone than in any other zone. In contrast, paqr5b zebrafish stayed in all three zones for approximately the same amount of time, even after exposure to ATP and cadaverine. The paqr5b fish were attracted to DHP and stayed in the right zone longer. Paqr5b zebrafish of either sex were not reactive to DHP exposure. These results showed that paqr5b zebrafish lacking olfactory neurons lost responsiveness to odorants and pheromones.
在我们之前的研究中，我们构建了膜型孕酮受体γ（paqr5b）基因敲除的斑马鱼品系。通过基因组编辑敲除paqr5b导致嗅球（OR）中的神经元缺失。这些发现表明Paqr5b在嗅觉神经元的形成中起重要作用。在本研究中，我们调查了缺乏嗅觉神经元的paqr5b斑马鱼保留嗅觉的程度。我们使用一个报道过的用于斑马鱼嗅觉分析的水槽，中间有一个分隔板。水槽被分为三个区域：右侧区域，用于添加测试物质；中性区域；以及左侧区域。每次测试开始时，将鱼放入中性区域，在右侧区域的角落添加化学物质，并拍摄3分钟的视频以跟踪鱼的运动。然后回放视频，并手动计算鱼在三个区域中停留的时间。分别分析了暴露于ATP、尸胺和信息素17α,20β - 二羟基 - 4 - 孕烯 - 3 - 酮（DHP）后，雄性和雌性paqr5b和paqr5b斑马鱼在三个区域中停留的时间。雄性和雌性paqr5b斑马鱼都被ATP强烈吸引，并在右侧区域停留约2分钟（67%）。此外，paqr5b斑马鱼避开尸胺，在左侧区域停留的时间比在其他任何区域都长。相比之下，即使暴露于ATP和尸胺后，paqr5b斑马鱼在所有三个区域停留的时间大致相同。paqr5b斑马鱼被DHP吸引，并在右侧区域停留更长时间。任何性别的paqr5b斑马鱼对DHP暴露均无反应。这些结果表明，缺乏嗅觉神经元的paqr5b斑马鱼对气味剂和信息素失去了反应能力。
