Baculoviruses constitute a large group of invertebrate DNA viruses, predominantly infecting larvae of the insect order Lepidoptera. During a baculovirus infection, the virus spreads throughout the insect body producing a systemic infection in multiple larval tissues. Some behavioral and physiological changes in lepidopteran larvae have been described following a baculovirus infection and those changes could be connected with alterations in the host central nervous system (CNS). As a main component of the CNS, neuropeptides are small protein-like molecules functioning as neurohormones, neurotransmitters or neuromodulators. These peptides are involved in regulating animal physiology and behaviour and could also be targeted by baculoviruses in order to achieve host behavioural manipulations leading to increased viral fitness. In this study, we have investigated the effect of a Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) infection on the neuropeptidome gene expression of Spodoptera exigua larval heads and brains. Expression of the gene encoding the neuropeptide proctolin was severely downregulated following infection and was chosen for further analysis. A recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) overexpressing the S. exigua proctolin gene was generated and used in bioassays using S. exigua larvae to study its influence on the viral infection. AcMNPV-proctolin infected larvae showed less locomotion activity and suffered a loss of weight compared to larvae infected with wild type AcMNPV or mock-infected larvae. These results provide additional information on the role of proctolin during a baculovirus infection, and offers a novel hypothesis for the molecular bases for the behavioral changes associated with a baculovirus infection.

中文翻译：

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杆状病毒感染后的神经肽组调节。着重于Proctolin及其在运动和消化中的相关性

杆状病毒构成一大类无脊椎动物DNA病毒，主要感染鳞翅目昆虫的幼虫。在杆状病毒感染期间，病毒传播到整个昆虫体内，在多个幼虫组织中产生全身感染。已经描述了杆状病毒感染后鳞翅目幼虫的一些行为和生理变化，这些变化可能与宿主中枢神经系统（CNS）的改变有关。作为中枢神经系统的主要成分，神经肽是小的蛋白质样分子，起着神经激素，神经递质或神经调节剂的作用。这些肽参与调节动物的生理和行为，也可被杆状病毒靶向，以实现宿主行为操纵，从而提高病毒适应性。在这个研究中，我们已经研究了斜纹夜蛾多核多角体病毒（SeMNPV）感染对斜纹夜蛾幼虫头部和大脑神经肽组基因表达的影响。感染后，编码神经肽proctolin的基因的表达严重下调，并选择进行进一步分析。产生了过量表达S. exigua procctolin基因的重组加利福尼亚州产的Autographa californica多核多角体病毒（AcMNPV），并将其用于使用S. exigua幼虫的生物测定中，以研究其对病毒感染的影响。与被野生型AcMNPV或模拟感染的幼虫感染的幼虫相比，AcMNPV-proctolin感染的幼虫显示出较少的运动活性，并且体重减轻。这些结果提供了有关杆状蛋白在杆状病毒感染中的作用的其他信息，