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机械感觉毛细胞对于脊椎动物的听力和平衡能力至关重要,低等脊椎动物毛细胞在遭受损伤后具有很强的再生能力。鱼类侧线神经丘毛细胞与内耳毛细胞具有相似的结构、功能、发育和再生过程。我们将受精后5~6 d的斑马鱼仔鱼置于400μmol/L新霉素溶液中处理1 h破坏神经丘毛细胞。分别对处理后2、4、8、12及24 h的斑马鱼仔鱼进行组织学切片及功能基因eya1和six1b的整体原位杂交。组织学切片结果显示:对照组神经丘毛细胞与支持细胞形态及排布都很规则,毛细胞和支持细胞分别位于上层和下层;处理后2~4 h,上层毛细胞数量显著下降;处理后8~12h,支持细胞和毛细胞之间界限模糊,部分支持细胞变长,且与基膜脱离;处理后24 h,部分神经丘内毛细胞及支持细胞数量、形态及排布接近对照组水平。整体原位杂交结果显示:eya1和six1b在对照组斑马鱼仔鱼整个神经丘都有表达;处理后4 h内神经丘中央毛细胞中eya1和six1b的表达量显著下降,周围的支持细胞中仍保持一定量的表达;这两个基因的表达量从处理后8 h起逐渐提高,在处理后12~24 h恢复甚至超过对照组。综上结果表明:神经丘毛细胞再生过程中可能有支持细胞的参与,且重启了神经丘毛细胞发育过程中的功能基因eya1和six1b。
The mechanical sensation of hair cells is crucial for vertebrate hearing and balance, and lower vertebrate hair cells have strong regenerative capacity after being damaged. The fish’s lateral neurovascular cells have similar structure, function, development and regeneration processes with inner ear hair cells. We put the zebra fish 5 ~ 6 d after fertilization in 400μmol / L neomycin solution for 1 h to destroy the neurovascular cells. Histological sections and functional in situ hybridization of eya1 and six1b were performed on zebrafish larvae at 2, 4, 8, 12 and 24 h after treatment respectively. The results of histological sections showed that the shape and arrangement of neuronal hair follicle cells and supporting cells in the control group were regular, the hair cells and supporting cells were located in the upper and lower layers, and the numbers of upper hair cells decreased significantly after 2-4 h of treatment. 8 ~ 12h, the boundaries between the supporting cells and hair cells were blurred, some of the supporting cells became longer and detached from the basement membrane. At 24 h after treatment, the number, shape and arrangement of hair cells and supporting cells in the part of the neuron were close to those of the control group . Whole-mount in situ hybridization showed that eya1 and six1b were expressed in the neuronal cortex of zebra fish in the control group. The expression of eya1 and six1b in the central hair cells of the neurovascular dune decreased significantly within 4 h after treatment, and remained in the surrounding supporting cells A certain amount of expression; The expression of these two genes gradually increased from 8 h after treatment, recovered or even exceeded the control group 12 to 24 h after treatment. Taken together, the results show that there may be supportive cells involved in the regeneration of neuronal hair follicles, and eya1 and six1b functional genes in the development of neuronal hair follicles are restarted.