Recruitment and degeneration of mitochondrion-rich cells in the gills of Mozambique tilapia Oreochromis mossambicus during adaptation to a hyperosmotic environment
Recruitment and degeneration of mitochondrion-rich cells in the gills of Mozambique tilapia Oreochromis mossambicus during adaptation to a hyperosmotic environment
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DOI：
10.1016/j.cbpa.2012.03.018
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发表时间：
2012-07-01
影响因子：
2.3
通讯作者：
Kaneko, Toyoji
中科院分区：
文献类型：
--
作者：
Inokuchi, Mayu;Kaneko, Toyoji
研究了莫桑比克罗非鱼从低渗水向高渗水转化过程中鳃线粒体(MR)细胞的募集和退化情况。为了检测与盐度变化相关的鳃细胞凋亡，将罗非鱼从淡水直接转移到70%的海水中。原位末端标记法检测显示，在移植后1d，鳃中的凋亡细胞显著增加，这与电子显微镜观察到的鳃MR细胞发生了以凋亡为特征的形态变化，如形状不规则的电子致密核和肾小管系统的扩张相一致。为了进一步检测MR细胞的募集，在注入BrdU后，将淡水驯化的罗非鱼转移到淡水或70%的海水中。通过对BrdU标记的细胞核和富含Na+/K+-ATPase的MR细胞的免疫组织化学检测，我们可以将BrdU标记的MR细胞分为两种亚型：单个MR细胞和MR-细胞复合体。虽然新产生的单个MR细胞在淡水和70%海水转移鱼中都能观察到，但70%海水中MR细胞复合体的密度比淡水高得多。我们的研究结果表明，从低渗水到高渗水的转移促进了淡水型MR细胞的凋亡，导致淡水适应的高渗透调节能力降低，并刺激了MR细胞复合体的招募，以发展对海水适应的低渗透调节能力。(C)2012 Elsevier Inc.保留所有权利。
Cellular recruitment and degeneration of branchial mitochondrion-rich (MR) cells were examined in Mozambique tilapia transferred from hypoosmotic to hyperosmotic water. To examine apoptosis in the gills associated with salinity change, tilapia were directly transferred from freshwater to 70% seawater. The TUNEL assay showed that apoptotic cells in the gills were significantly increased at 1 day after transfer, which was supported by an electron-microscopic observation that gill MR cells underwent morphological changes characteristic of apoptosis such as an irregularly shaped electron-dense nucleus and distension of the tubular system. To further examine MR-cell recruitment, freshwater-acclimated tilapia were transferred either to freshwater or to 70% seawater after BrdU injection. Immunohistochemical detection of BrdU-labeled nuclei and Na+/K+-ATPase-rich MR cells allowed us to classify BrdU-labeled MR cells into two subtypes: a single MR cell and an MR-cell complex. Although newly generated single MR cells were observed similarly in both freshwater and 70% seawater-transferred fish, the density of MR-cell complexes was much higher in 70% seawater than in freshwater. Our findings indicated that transfer from hypoosmotic to hyperosmotic water enhanced apoptosis of freshwater-type MR cells, resulting in reduction in hyperosmoregulatory ability for freshwater adaptation, and stimulated the recruitment of MR-cell complexes to develop hypoosmoregulatory ability for seawater adaptation. (C) 2012 Elsevier Inc. All rights reserved.