Altuntaş H, Kılıç A Y, Uçkan F, Ergin E
Department of Biology, Faculty of Science, Anadolu University, Eskişehir, Turkey.
Environ Entomol. 2012 Jun;41(3):688-96. doi: 10.1603/EN11307.
The impacts of different doses of the plant growth regulator gibberellic acid (GA(3)) in diet on the number of total and differential hemocytes, frequency of apoptotic, and necrotic hemocytes, mitotic indices, encapsulation, and melanization responses were investigated using the greater wax moth Galleria mellonella L. (Lepidoptera: Pyralidae) larvae. Total hemocyte counts increased in G. mellonella larvae at all treatment doses whereas GA(3) application had no effect on the number of different hemocyte types. The occurrence of apoptosis, necrosis and mitotic indices in GA(3) treated and untreated last instars were detected by acridine orange or ethidium bromide double staining by fluorescence microscopy. While the ratio of necrotic hemocytes increased at all GA(3) treatments, that of late apoptotic cells was only higher at doses >200 ppm when compared with untreated larvae. The percentage of mitotic index also increased at 5,000 ppm. Positively charged DEAE Sephadex A-25 beads were used for analysis of the levels of encapsulation and melanization in GA(3) treated G. mellonella larvae. At four and 24 h posttreatments with Sephadex A-25 bead injection, insects were dissected under a stereomicroscope. Encapsulation rates of larval hemocytes were dependent on the extent of encapsulation and time but not treatment groups. While the extent of melanization of hemocytes showed differences related to time, in general, a decrease was observed at all doses of GA(3) treated larvae at 24 h. We suggest that GA(3) treatment negatively affects hemocyte physiology and cell immune responses inducing cells to die by necrosis and apoptosis in G. mellonella larvae.
利用大蜡螟幼虫（鳞翅目：螟蛾科），研究了日粮中不同剂量的植物生长调节剂赤霉酸（GA(3)）对总血细胞和不同类型血细胞数量、凋亡和坏死血细胞频率、有丝分裂指数、包囊化和黑化反应的影响。在所有处理剂量下，大蜡螟幼虫的总血细胞计数均增加，而GA(3)处理对不同类型血细胞的数量没有影响。通过荧光显微镜用吖啶橙或溴化乙锭双重染色检测GA(3)处理和未处理的末龄幼虫中凋亡、坏死和有丝分裂指数的发生情况。虽然在所有GA(3)处理中坏死血细胞的比例都增加了，但与未处理的幼虫相比，晚期凋亡细胞的比例仅在剂量>200 ppm时更高。有丝分裂指数百分比在5000 ppm时也增加。使用带正电荷的DEAE葡聚糖A-25珠子分析GA(3)处理的大蜡螟幼虫的包囊化和黑化水平。在用葡聚糖A-25珠子注射处理后4小时和24小时，在体视显微镜下解剖昆虫。幼虫血细胞的包囊化率取决于包囊化程度和时间，而不是处理组。虽然血细胞的黑化程度显示出与时间相关的差异，但总体而言，在24小时时，所有剂量GA(3)处理的幼虫中均观察到黑化程度降低。我们认为，GA(3)处理对血细胞生理和细胞免疫反应有负面影响，导致大蜡螟幼虫细胞通过坏死和凋亡死亡。
