Lima Raquel N, Kültz Dietmar
University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
J Exp Biol. 2004 Apr;207(Pt 10):1729-39. doi: 10.1242/jeb.00930.
The effects of salinity on chloride cells (CC) and Na(+)/K(+)-ATPase content in gill epithelium of euryhaline killifish Fundulus heteroclitus were analyzed using laser scanning cytometry (LSC) and tissue microarrays (TMAs). Salinity acclimations consisted of acute transfer from freshwater (FW) to 1x seawater (SW) and gradual transfer from FW to 2.4x SW. Suspensions of dissociated gill epithelial cells were stained with DASPMI and evaluated using LSC. CC number and volume are proportional to external salinity, being lower in FW (0.5+/-0.2 x 10(5) and 405+/-32 micro m(3), respectively) and higher after 5 weeks in 2.4x SW (3.7+/-0.9 x 10(5) and 2697+/-146 micro m(3), respectively). TMAs were constructed from fixed gill tissues and developed using antibody for Na(+)/K(+)-ATPase to visualize CCs in situ and compare their characteristics with isolated CCs. Na(+)/K(+)-ATPase content per CC increases transiently (from 2.2+/-0.5 x 10(6) to 4.8+/-1.1 x 10(6) relative fluorescence units, RFU) after 1 week of acute acclimation to 1x SW but returns to baseline values (2.4+/-0.5 x 10(6) RFU) within 5 weeks. In contrast, gradual acclimation to 2.4x SW permanently increases Na(+)/K(+)-ATPase content per CC (from 2.0+/-0.8 x 10(6) to 6.7+/-2.7 x 10(6) RFU after 5 weeks). CC size in situ did not correlate well to salinity because of basolateral membrane infoldings. Taken together, these data suggest that euryhaline fishes are capable of sensing environmental salinity to utilize transient short-term and permanent long-term adaptations for coping with salinity changes. These results also demonstrate the power of LSC and TMA for comparative biology.
利用激光扫描细胞术（LSC）和组织微阵列（TMA）分析了盐度对广盐性鳉鱼（Fundulus heteroclitus）鳃上皮中氯化物细胞（CC）和Na(+)/K(+)-ATP酶含量的影响。盐度驯化包括从淡水（FW）急性转移到1倍海水（SW）以及从FW逐渐转移到2.4倍SW。解离的鳃上皮细胞悬液用DASPMI染色，并使用LSC进行评估。CC的数量和体积与外部盐度成正比，在FW中较低（分别为0.5±0.2×10(5)和405±32μm(3)），在2.4倍SW中5周后较高（分别为3.7±0.9×10(5)和2697±146μm(3)）。TMA由固定的鳃组织构建而成，并使用针对Na(+)/K(+)-ATP酶的抗体进行显色，以原位观察CC，并将其特征与分离的CC进行比较。急性适应1倍SW 1周后，每个CC的Na(+)/K(+)-ATP酶含量短暂增加（从2.2±0.5×10(6)相对荧光单位，RFU增加到4.8±1.1×10(6) RFU），但在5周内恢复到基线值（2.4±0.5×10(6) RFU）。相比之下，逐渐适应2.4倍SW会使每个CC的Na(+)/K(+)-ATP酶含量永久增加（5周后从2.0±0.8×10(6)增加到6.7±2.7×10(6) RFU）。由于基底外侧膜褶皱，原位CC大小与盐度的相关性不佳。综上所述，这些数据表明广盐性鱼类能够感知环境盐度，利用短暂的短期和永久的长期适应来应对盐度变化。这些结果也证明了LSC和TMA在比较生物学中的作用。
