Molecular cloning, transcriptional regulation, and differential expression profiling of vitellogenin in two wing‐morphs of the brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae)
Molecular cloning, transcriptional regulation, and differential expression profiling of vitellogenin in two wing‐morphs of the brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae)
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DOI：
10.1111/j.1365-2583.2010.01035.x
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发表时间：
2010-12
影响因子：
2.6
通讯作者：
M. Tufail;M. Naeemullah;M. Elmogy;M. Elmogy;P. N. Sharma;M. Takeda;C. Nakamura
中科院分区：
文献类型：
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作者：
M. Tufail;M. Naeemullah;M. Elmogy;M. Elmogy;P. N. Sharma;M. Takeda;C. Nakamura
褐飞虱Nilaparvata lugens是一种严重危害亚洲水稻的害虫，其翅型具有二型性，短翅型成虫翅发育不全，而长翅型成虫翅发育完全。为了了解这种昆虫的两种翅型的生殖策略，克隆了编码主要卵黄蛋白前体卵黄蛋白原（Vg）的转录本。完整的mRNA转录本为6314 bp，编码2063个残基的蛋白质，包括18个残基的推定信号肽。成熟蛋白的分析揭示了两个卵黄蛋白原-N（或脂蛋白氨基末端）结构域靠近N-末端和一个血管性血友病因子D型结构域靠近C-末端。此外，在C末端附近鉴定出高度保守的基序GL/ICG和许多半胱氨酸残基。北方印迹分析鉴定了一个约6.8 kb的Vg基因转录本，该转录本仅在成年雌性脂肪体细胞中表达。表达谱显示，Vg基因在短翅目中开始表达较早（在第3天），而在大翅目中在第4天观察到mRNA转录物。然而，在这两种变体中，Vg mRNA的量在卵黄发生期[从第4天（短翅目）和第5天（长翅目）及以后]增加到高水平。反映的RNA转录模式，Vg信号检测到免疫印迹在第3天和第4天，分别在血淋巴的短翅和macropterous女性，每天增加，并保持在卵黄发生期间高。此外，局部施用保幼激素（JH）III上调了Vg基因的表达，表明Vg基因在N. lugens。Southern杂交分析表明，该基因在N.褐飞虱基因组在本研究中，大翅类雌性动物的表达（转录本和蛋白质）呈延迟趋势，这支持了这一翅型物种生殖前长距离迁移的假设。
The brown planthopper, Nilaparvata lugens, is a serious pest of rice crops throughout Asia and exhibits wing dimorphism, with brachypterous adults having reduced wings and macropterous adults possessing fully developed wings. To understand the reproductive strategies in two wing‐morphs of this insect, the transcript encoding the major yolk protein precursor, vitellogenin (Vg), was cloned. The complete mRNA transcript was 6314 bp, which encodes a protein of 2063 residues including an 18‐residue putative signal peptide. Analysis of the mature protein revealed two vitellogenin‐N (or lipoprotein amino‐terminal) domains near the N‐terminus and a von Willebrand factor type D domain near the C‐terminus. In addition, a highly conserved motif GL/ICG, and a number of cysteine residues were identified near the C‐terminus. Northern blot analysis identified a ∼6.8 kb Vg gene transcript that was expressed exclusively in the adult female fat body cells. The expression profile revealed that the Vg gene starts to be expressed earlier (on day 3) in brachypters as compared to macropters where the mRNA transcript was observed on day 4. However, in both morphs, the amount of Vg mRNA increased to reach high levels during vitellogenic periods [from day 4 (in brachypters) and day 5 (in macropters) and onwards]. Reflecting the RNA transcription pattern, the Vg signal was detected by immunoblotting on day 3 and day 4 in haemolymph of brachypterous and macropterous females, respectively, and that was increased every day and remained high during the vitellogenic periods. Furthermore, the topical application of juvenile hormone (JH) III had up‐regulated the Vg gene expression suggesting that the Vg gene is regulated by JH in N. lugens. In addition, it was demonstrated by Southern blot analysis that there exists a single copy of the gene in the N. lugens genome. A delayed trend in expression (of both the transcript and the protein) demonstrated by macropterous females in the present studies supports the hypothesis of prereproductive long distance migration in this wing‐dimorphic species.