›› 2010, Vol. 53 ›› Issue (9): 969-977.

• 研究论文 • 上一篇    下一篇

重金属Cd2+对棕尾别麻蝇血细胞数量、包囊作用和形态结构的影响

李艳敏, 方琦, 胡萃, 叶恭银   

  • 出版日期:2010-09-20 发布日期:2010-09-20
  • 通讯作者: 叶恭银

Effects of cadmium on hemocyte number, encapsulation and morphology in Boettcherisca peregrina (Diptera: Sarcophagidae)

LI Yan-Min   

  • Online:2010-09-20 Published:2010-09-20

摘要:

为了揭示重金属对昆虫细胞免疫的影响及其机理,本文采用血细胞计数、台盼蓝染色、延展与包囊率测定, 以及显微与超微结构观察等方法,以经重金属Cd2+(浓度为150 μg/g)处理的棕尾别麻蝇Boettcherisca peregrina及其对照为研究对象,分别测定了处理组与对照组血细胞的数量与存活率、延展与包囊率,观察其形态结构,并比较了两组间的差异。结果表明: 棕尾别麻蝇初产幼虫经连续喂饲含Cd2+的饲料24,48,72和96 h后,与对照相比其血细胞总数和存活率显著下降,而血细胞的延展率和包囊作用的显著下降则分别出现于取食72和48 h之内,此后则下降不显著;由Cd2+处理幼虫发育形成蛹的血细胞包囊作用也显著低于对照。形态结构观察结果表明,Cd2+处理对幼虫的原血细胞、浆血细胞、颗粒血细胞和类绛色血细胞的显微形态影响不大,但可导致部分浆血细胞不能产生伪足;但均能导致各类血细胞的超微结构发生不同程度的变化,其中主要变化包括:细胞膜受损或破裂,染色质呈现凝聚, 线粒体和内质网等细胞器明显减少,以及胞质内出现空囊泡。结果说明重金属Cd2+对棕尾别麻蝇的血细胞可具有毒害作用。

关键词: 棕尾别麻蝇, 重金属污染, 细胞免疫, Cd离子, 血细胞, 包囊作用, 显微结构, 超微结构

Abstract:

 In order to explore the effects of heavy metals on insect cellular immunity and its related mechanism, the differences in the number, viability, spreading and encapsulation rates, and morphology of hemocytes between the Cd2+ treated (at the concentration of 150 μg/g) Boettcherisca peregrina and its control were investigated and compared, respectively, using the methods as hemocytes counting, typan blue staining, spreading and encapsulation assays, as well as microstructure and ultrastructure observations. The results indicated that at 24, 48, 72 and 96 h post feeding the neonate larvae of B. peregrina with the artificial diet containing Cd2+, both total hemocyte count and hemocytes viability in the larvae were significantly decreased compared with the control, respectively. In contrast, the in vitro spreading rate and encapsulation capability of hemocytes of the larvae exposed to Cd2+ were significantly lower than those of the control after 72 and 48 h exposure, respectively, and then showed no significant differences with the control. Additionally, the in vivo encapsulation capability of hemocytes of the pupae that developed from the larvae exposed to Cd2+ was also significantly lower than that of the control. The morphological observation results showed that compared with the control, no marked alternation in the microstructure was observed for each type of hemocytes (including prohemocyte, plasmatocyte, granulocyte and oenocytoid), except that some plasmatocytes neither spread nor extended their pseudopods. However, the ultrastructure of each type of hemocytes in the exposed larvae was found to be alternated to various degrees compared to the control, with the main ultrastructural alternation including: damage or break of cell membrane, condensation of chromatin, sharply decreasing of the number of mitochondria, endoplasmic reticulum and other organelles, and the emergence of vacuoles in cytoplasm. The results suggest that heavy metal Cd2+ may have toxic effects on hemocytes of B. peregrina.

Key words: Boettcherisca peregrina, heavy metal pollution, cellular immunity, cadmium, hemocyte, encapsulation, microstructure, ultrastructure