粘虫不同发育期体内储存蛋白的检测及苦皮藤素Ⅴ对其含量的影响

采用PAGE和SDS-PAGE以及Western blot 的方法，分析了粘虫Mythimna separata幼虫、蛹及成虫体内的储存蛋白。结果表明，粘虫体内存在两种储存蛋白，其中一种为SP-1,即幼虫特异性储存蛋白,从6龄粘虫幼虫的2日龄开始出现在血淋巴中，到末日龄时达到峰值，停止取食后从血淋巴中消失；另一种为SP-3,在化蛹时开始出现在脂肪体中，一直到成虫期仍可持续表达，因此属于持续性储存蛋白。SP-1为分子量约94 kD和100 kD的2种亚基组成的蛋白质，而SP-3为分子量约94 kD的1种亚基组成的蛋白质。SP-1含8.16%的芳香类氨基酸，3.06%的甲硫氨酸。经苦皮藤素Ⅴ亚致死剂量处理5龄粘虫幼虫后的6龄2、3、4日龄粘虫幼虫体内储存蛋白的含量明显低于对照组，对5日龄后粘虫处理组和对照组体内储存蛋白的含量及雌性成虫产卵量没有明显影响。

Detection of storage proteins in different developmental stages of Mythimna separata and the effect of celangulin V on their content

The storage proteins in Mythimna separata were studied by means of native PAGE, SDS-PAGE and Western blot. The results indicated that there were two storage proteins (SP-1 and SP-3) in M. separata. SP-1 was detected on the 2nd day of the 6th instar of M. separata, and its concentration in the hemolymphincreased with the age and reached to a peak on the last day of the 6th instar. SP-1 disappeared in the hemolymph when the larva ceased feeding. In the adult stage only SP-3 was found. SP-3 as persistent storage protein appeared in the fat body of pupa, and was continuously expressed till the adult stage. SP-1 was composed of two subunits of the molecular size of 94 kD and 100 kD respectively. SP-3 was composed of one subunit in size of 94 kD. The native molecular weights of these two storage proteins were all 550 kD. Analysis of the amino acid compositions of SP-1 showed that the content of aromatic acids (Phe and Tyr) was 8.16% and the content of methionine 3.06%. The contents of the storage proteins in 2nd, 3rd, 4th day of the last instar larvae treated with celangulin Ⅴ in the sublethal dosage were markedly lower than that in the control group. But beyond the 5th day of the last instar, no difference was tested in the contents of the storage proteins and the number of eggs laid per female adult between the group treated with celangulin Ⅴ and the control.