Parasite-induced enhancement of hemolymph tyrosinase activity in a selected immune reactive strain of Drosophila melanogaster.
Parasite-induced enhancement of hemolymph tyrosinase activity in a selected immune reactive strain of Drosophila melanogaster.
复制标题
在选定的黑腹果蝇免疫反应菌株中，寄生虫诱导的血淋巴酪氨酸酶活性增强。
DOI：
10.1002/arch.940180304
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发表时间：
1991
影响因子：
2.2
通讯作者：
Frey,F
中科院分区：
文献类型：
--
作者：
Nappi,AJ;Carton,Y;Frey,F
采用高效液相色谱-电化学检测法测定了果蝇幼虫血淋巴酪氨酸酶活性。该酶使L酪氨酸羟基化，氧化二酚底物L多巴和多巴胺。在一株免疫反应性品系的幼虫体内，在寄生蜂Leptopilina Boulardi的卵被黑化的早期阶段，酪氨酸羟化、多巴氧化和多巴胺氧化的速率显著增加。在被寄生的幼虫中，酪氨酸酶活性没有改变。在寄主黑腹蜂中，寄生蜂的发育没有受到干扰。在寄生的同一时期，免疫反应性幼虫体内的游离酪氨酸含量约为敏感寄主的3倍。这些数据表明，免疫反应菌株的酪氨酸酶系统在寄生过程中被激活，这导致一些前体的合成，最终在寄生虫卵周围产生黑化和硬化壳。根据已知的果蝇酶系统的遗传信息，似乎至少有两个基因参与了激活过程，一个与单酚氧化酶活性的酶原有关，另一个与二酚氧化酶的酶原活性有关。
Larval hemolymph tyrosinase activity inDrosophila melanogasterwas detected with high performance liquid chromatography with electrochemical detection. The enzyme hydroxylated L‐tyrosine, and oxidized the diphenol substrates L‐dopa and dopamine. In larvae of a selected immune‐reactive strain the rates of tyrosine hydroxylation, dopa oxidation, and dopamine oxidation were markedly increased during the early stages of melanotic encapsulation of the eggs of the parasitic waspLeptopilina boulardi. Tyrosinase activity was not modified in parasitized larvae of a selected susceptible strain ofD. melanogaster, in which hosts the parasitoids developed unmolested. During the same period of parasitization, the amount of free tyrosine in immune reactive larvae was approximately three times higher than in susceptible hosts. These data indicate that the tyrosinase system of the immune reactive strain is activated during parasitization, and this results in the synthesis of some precursors which ultimately produce a melanotic and sclerotic capsule around the eggs of the parasite. Based on known genetic information of the enzyme system inDrosophila, it appears that at least two genes may be involved in the activation process, one associated with the proenzyme for monophenol oxidase activity, and the second with the proenzyme for diphenol oxidase activity.