盐度骤变对金钱鱼幼鱼鳃线粒体丰富细胞形态结构的影响

文章采用显微技术研究了盐度骤降(20盐度组投入5盐度组)、盐度骤升(20盐度组投入35盐度组)胁迫下,金钱鱼(Scatophagus argus)幼鱼鳃线粒体丰富细胞(Mitochondria-rich cells,MRCs)形态结构的变化。结果显示,低盐胁迫3 h MRCs长径(9.517±1.390)μm]和短径(7.150±1.448)μm]较对照组长径(7.317±0.986)μm]和短径(5.067±0.467)μm]显著增大(P<0.05),高盐胁迫6 h MRCs数量显著增加。显微结果表明,胁迫24 h鳃丝处于渗透机制的主动调节阶段;超微结构观察发现鳃丝分化出2种类型的MRCs:1)Ⅰ型MRCs,椭圆形,胞核形状不规则,内脊发达,顶端开口处于关闭或开放状态,主要存在于低盐环境;2)Ⅱ型MRCs,圆形,胞核规则呈圆形,具有多个顶端开口。具不同形状的线粒体,a型线粒体着色较浅,呈短粗状;b型线粒体着色较深,呈小的颗粒状,主要存在于高盐环境。综上所述,金钱鱼幼鱼对盐度骤变产生应答反应机制,通过MRCs体积、数量、形状结构,以及线粒体的形状结构变化共同维持内环境稳定。

Effect of abrupt salinity change on morphology and structure of mitochondria-rich cells in Scatophagus argus

The morphological changes of mitochondria rich cells(MRCS)in gills of juvenile goldfish(Scatophagus argus)were studied by microscopic technique under the stress of sudden salinity drop(20 salinity group put into 5 salinity group)and salinity sudden rise(20 salinity group put into 35 salinity group).The results show that the long and short diameters of MRCs were(9.517±1.390)μm and(7.150±1.448)μm,respectively,significantly higher than those of the control which were(7.317±0.986)μm and(7.317±0.986)μm(P<0.05),respectively;and the MRCs number increased significantly at 6^thhour.Two types of MRCs were discovered:Type I MRCs,oval in shape with irregular nuclei,well-developed inner ridges and closed or open apical openings;Type II MRCs,round,with regular round nuclei and multiple apical openings.With different shapes of mitochondria,Type a mitochondria were slightly stained,showing short and thick shape;Type b mitochondria were more deeply stained,showing small granular.The results indicate that juvenile S.argus will produce a response mechanism through the changes of MRCs volume,quantity,shape and structure,as well as the shape and structure of mitochondria in order to maintain the stability of internal environment.