Drosophila ABC transporter mutants white, brown and scarlet have altered contents and distribution of biogenic amines in the brain
Drosophila ABC transporter mutants white, brown and scarlet have altered contents and distribution of biogenic amines in the brain
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DOI：
10.1242/jeb.021162
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发表时间：
2008-11-01
影响因子：
2.8
通讯作者：
Meinertzhagen, I. A.
中科院分区：
文献类型：
--
作者：
Borycz, J.;Borycz, J. A.;Meinertzhagen, I. A.
单胺类物质如多巴胺、组胺和5-羟色胺（5-HT）广泛分布于果蝇（Drosophila melanogaster）的脑内，它们的许多作用已被研究。例如，组胺从视觉系统的神经纤维层中的光感受器突触释放。基因白色（果蝇遗传学中编码ABC转运蛋白的重要眼色素标记）及其结合伴侣棕色的突变，导致神经表型不容易仅与眼色素沉着中的作用相协调。我们发现，这些基因突变的果蝇，以及另一种结合伴侣，猩红色，头部的组胺含量约为野生型的一半，同时5-HT和多巴胺含量也减少了。这些差异平行减少相应的生物胺的免疫反应性。它们还与头部匀浆差速离心后的组分的胺含量相关。因此，大部分的胺被发现在野生型头部匀浆的囊泡丰富的部分，而它被发现在从白色，棕色和猩红色苍蝇的上清液部分。白色与Ebony在薄层上皮神经胶质中共表达，Ebony将组胺与β-丙氨酸结合。当结合物在光感受器中被Tan水解时，组胺被释放。突变的白色改善了晒黑对头部组胺的影响，而它加剧了乌木的影响。我们的研究结果是一致的建议，上皮胶质细胞的组胺摄取可能是白色依赖。白色、棕色和猩红色突变体的行为异常可能是因为果蝇大脑中的胺能神经元释放的胺减少。
Monoamines such as dopamine, histamine and serotonin (5-HT) are widely distributed throughout the brain of the fruit fly Drosophila melanogaster, where many of their actions have been investigated. For example, histamine is released from photoreceptor synapses in the lamina neuropile of the visual system. Mutations of the genes white, an important eye pigmentation marker in fly genetics that encodes an ABC transporter, and its binding partner brown, cause neural phenotypes not readily reconciled solely with actions in eye pigmentation. We find that flies mutant for these genes, and another binding partner, scarlet, have about half the wild-type amount of histamine in the head, as well as reduced 5-HT and dopamine. These differences parallel reductions in immunoreactivity to the corresponding biogenic amines. They also correlate with the amine content of fractions after differential centrifugation of head homogenates. Thus, most of the amine is found in the vesicle-rich fraction of wild-type head homogenates, whereas it is found in the supernatant fractions from white, brown and scarlet flies. White co-expresses in lamina epithelial glia with Ebony, which conjugates histamine to beta-alanine. Histamine is then released when the conjugate is hydrolyzed in photoreceptors, by Tan. Mutant white ameliorates the effects of tan on head histamine whereas it exacerbates the effects of ebony. Our results are consistent with the proposal that histamine uptake by the epithelial glia may be white dependent. Behavioral abnormalities in white, brown and scarlet mutants could arise because aminergic neurons in the Drosophila brain have reduced amine for release.