论文部分内容阅读
采用扫描电镜观察了不同碱度(0、2、4 g/L Na HCO_3)胁迫对尼罗罗非鱼(Oreochromis niloticus)鳃离子细胞形态变化的影响,并采用免疫组化技术观察了鳃、肾、肠中4个HCO_3~-转运因子碳酸酐酶(CAⅡ、CAⅣ)、碳酸氢钠协同转运载体(SLC4A4)、Cl~-/HCO_3~-离子交换体(SLC26A6)的阳性反应变化。扫描电镜结果表明,鳃离子细胞分布在鳃小片基部。根据其表面开孔形状和尺寸,可分为Ⅰ型、Ⅱ型、Ⅲ型和Ⅳ型4种亚型,各亚型离子细胞的开孔尺寸随碱度胁迫强度增高呈正比增大,Ⅲ型离子细胞开孔尺寸变化最明显(P<0.01);离子细胞总数目也随碱度升高而增加,Ⅲ型离子细胞数目上升最为显著(P<0.01)。免疫组化结果表明,在淡水、碱水组中,CAⅡ、CAⅣ、SLC4A4、SLC26A6在鳃小片基部和肾中均有阳性反应,且随着碱度升高,阳性反应增强,但在肠道中未观察到阳性反应。本研究结果初步表明,尼罗罗非鱼可通过鳃离子细胞形态和数量调节适应碱度变化,鳃和肾为主要应答调节器官。
The morphological changes of gill ion of Nile tilapia (Oreochromis niloticus) under different alkalinity (0, 2, 4 g / L Na HCO 3) stress were observed by scanning electron microscopy. Immunohistochemistry was used to observe the changes of gill, (CⅡ, CA Ⅳ), sodium bicarbonate synergistic transporter (SLC4A4) and Cl ~ - / HCO 3 - ion exchanger (SLC26A6) in intestine. Scanning electron microscopy results showed that gill ion cells distributed at the base of gill platelets. According to the shape and size of the surface openings, it can be divided into four subtypes of type Ⅰ, type Ⅱ, type Ⅲ and type Ⅳ. The size of open pores of each subtype of ion cells increases proportionally with the increase of alkalinity, (P <0.01). The total number of ionic cells also increased with the increase of alkalinity, and the number of type Ⅲ ion cells increased most significantly (P <0.01). The results of immunohistochemistry showed that CAⅡ, CAⅣ, SLC4A4 and SLC26A6 had positive reaction in the base of gill and the kidney in fresh water and alkaline water group, and the positive reaction was enhanced with the increase of alkalinity, but not in the intestinal tract A positive reaction was observed. The preliminary results of this study showed that Nile tilapia could regulate the adaptation of alkalinity by the morphology and quantity of gill ion cells, with gills and kidneys as the major regulatory organs.