Huang C-Y, Chou S-Y, Bartholomay L C, Christensen B M, Chen C-C
Department of Tropical Medicine, National Yang-Ming University, Taipei, Taiwan.
Insect Mol Biol. 2005 Jun;14(3):237-44. doi: 10.1111/j.1365-2583.2004.00552.x.
Mosquito melanization involves hydroxylation of tyrosine to dopa, which then is oxidized to dopaquinone by phenoloxidase, or decarboxylated to dopamine by dopa decarboxlase (DDC). An Armigeres subalbatus cDNA encoding DDC was cloned and real-time PCR analysis revealed increased transcripts in blood-fed and microfilariae (mf)-inoculated mosquitoes. A double subgenomic Sindbis virus was used to silence DDC and assess its role in melanization of mf. DDC transcription and activity were significantly decreased in silenced mosquitoes, as was the degree of mf melanization 48 h postinoculation; however, melanization increased after 72 and 96 h, demonstrating that DDC influences the rate of melanization. DDC-silenced mosquitoes also exhibit high mortality, over-feeding and abnormal movement, consistent with an involvement of DDC in neurotransmission.
蚊虫黑化涉及酪氨酸羟基化为多巴，多巴随后被酚氧化酶氧化为多巴醌，或被多巴脱羧酶（DDC）脱羧为多巴胺。克隆了编码DDC的嗜人按蚊cDNA，实时PCR分析显示，在吸食血液和接种微丝蚴（mf）的蚊虫中，转录本增加。使用双亚基因组辛德毕斯病毒使DDC沉默，并评估其在mf黑化中的作用。在沉默的蚊虫中，DDC转录和活性显著降低，接种后48小时mf黑化程度也显著降低；然而，72小时和96小时后黑化增加，表明DDC影响黑化速率。DDC沉默的蚊虫还表现出高死亡率、过度进食和异常运动，这与DDC参与神经传递一致。
