A diphenol oxidase gene is part of a cluster of genes involved in catecholamine metabolism and sclerotization in drosophila. I. Identification of the biochemical defect in Dox-A2 [l(2)37Bf] mutants.
A diphenol oxidase gene is part of a cluster of genes involved in catecholamine metabolism and sclerotization in drosophila. I. Identification of the biochemical defect in Dox-A2 [l(2)37Bf] mutants.
复制标题
二酚氧化酶基因是果蝇儿茶酚胺代谢和硬化相关基因簇的一部分。
DOI：
10.1093/genetics/112.4.823
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发表时间：
1986
期刊：
影响因子：
3.3
通讯作者：
Wright,TR
中科院分区：
文献类型：
--
作者：
Pentz,ES;Black,BC;Wright,TR
酚氧化酶是一种复杂的酶，在昆虫角质层的硬化和黑化过程中起重要作用。据报道，几个基因座影响酚氧化酶活性水平，但迄今为止，仅鉴定出一个结构基因座[Dox-3F（2-53.1+）]。最近分离的Dox-A2突变（2-53.9）是隐性的，早期幼虫致死，作为杂合子降低酚氧化酶活性。一个纯合子突变逃生弱，完全无色素的角质层和无色素的刚毛。酶活性测定表明，Dox-A_2杂合子的二酚氧化酶活性降低到野生型的47-79%，而单酚氧化酶活性正常，为野生型的94-106%。在突变体中观察到二酚氧化酶底物多巴、多巴胺和N-乙酰多巴胺的池大小升高，证实了酶测定结果。在聚丙烯酰胺凝胶上分离三种酚氧化酶A组分的活性表明，Dox-A2突变只降低了A2组分的活性，Dox-A2可能是双酚氧化酶系统中A2组分的一个结构位点。Dox-A2位点是第二染色体多巴脱羧酶Df（2L）TW 130区的18个位点之一，其中至少有14个位点对角质层的形成、黑化或硬化有一定的影响。这些基因座形成功能相关基因的明显簇。
Phenol oxidase, a complex enzyme, plays a major role in the processes of sclerotization and melanization of cuticle in insects. Several loci have been reported to affect levels of phenol oxidase activity, but to date only one structural locus has been identified [Dox-3F(2-53.1+)]. Recently isolatedDox-A2mutations (2-53.9) are recessive, early larval lethals, which as heterozygotes reduce phenol oxidase activity. A homozygous mutant escaper had weak, completely unpigmented cuticle and unpigmented bristles. Enzyme assays show thatDox-A2heterozygotes have diphenol oxidase activity reduced to 47-79% of wild type, whereas monophenol oxidase activity, at 94-106% of wild type, is normal. Elevated pool sizes of the diphenol oxidase substrates DOPA, dopamine, andN-acetyldopamine are observed in the mutant, confirming the enzyme assay results. Separation of the three phenol oxidase A component activities on polyacrylamide gels shows thatDox-A2mutations reduce the activity of only the A2 component.Dox-A2may identify a structural locus for the A2 component of the diphenol oxidase enzyme system.—TheDox-A2locus is one of 18 loci in the dopa decarboxylase,Df(2L)TW130region of the second chromosome, at least 14 of which affect the formation, melanization or sclerotization of cuticle in some way. These loci form an apparent cluster of functionally related genes.