Structure and function of the musculoskeletal ovipositor system of an ichneumonid wasp
Structure and function of the musculoskeletal ovipositor system of an ichneumonid wasp
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DOI：
10.1186/s40850-018-0037-2
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发表时间：
2018-11-12
期刊：
影响因子：
1.6
通讯作者：
Betz, Oliver
中科院分区：
文献类型：
--
作者：
Eggs, Benjamin;Birkhold, Annette, I;Betz, Oliver
背景资料：修改的产卵器似乎发挥了突出的作用，在定义的寄主范围的寄生蜂hyperichterans，突出了一个重要的促成因素，在塑造他们的产卵策略，生活史和多样化。尽管有许多比较研究的结构，hyperteran terebra，鲜为人知的肌肉骨骼产卵系统的功能方面。因此，我们检查了所有固有的表皮元件和肌肉的ichdalonidae黄蜂黑星菌产卵器（Gravenhorst 1829），研究了产卵器系统的机制并确定了其功能模式。结果：我们发现，由雌性T9组成的产卵器的运动（第9腹背），两对瓣和三对瓣，由一组六对肌肉驱动。背侧的T9-第二瓣肌在V. canescens中被修改，并形成不同的束，连同拮抗作用的腹侧T9-第二瓣肌，改变第二瓣肌与雌性T9的相对位置。因此，它们间接倾斜第一瓣，因为它分别通过瓣间关节和背瓣关节与它们连接。第一个瓣膜充当杠杆臂，将运动传递给第一个瓣膜。在产卵过程中，T9-第二瓣肌和第一瓣-生殖膜肌起着稳定系统的作用。从我们对鱼的肌肉骨骼产卵器系统的研究中，我们讨论了杠杆作用和肌肉力量，并开发了一个基本工作机制的功能模型，增加了我们对一个关键特征的理解，这个关键特征在很大程度上决定了巨型生物多样性的进化成功。目前已发现的有24，000多个种。
Background: Modifications of the ovipositor appear to have played a prominent role in defining the host range of parasitoid hymenopterans, highlighting an important contributing factor in shaping their oviposition strategies, life histories and diversification. Despite many comparative studies on the structure of the hymenopteran terebra, little is known about functional aspects of the musculoskeletal ovipositor system. Therefore, we examined all inherent cuticular elements and muscles of the ovipositor of the ichneumonid wasp Venturia canescens (Gravenhorst 1829), investigated the mechanics of the ovipositor system and determined its mode of function.Results: We found that the movements of the ichneumonid ovipositor, which consists of the female T9 (9th abdominal tergum), two pairs of valvifers and three pairs of valvulae, are actuated by a set of six paired muscles. The posterior and the anterior 2nd valvifer-2nd valvula muscles flex and extend the terebra from its resting towards an active probing position and back The dorsal T9-2nd valvifer muscle is modified in V. canescens and forms distinct bundles that, together with the antagonistically acting ventral T9-2nd valvifer muscle, change the relative position of the 2nd valvifer to the female T9. Thereby, they indirectly tilt the 1st valvifer because it is linked with both of them via intervalvifer and tergo-valvifer articulation, respectively. The 1st valvifer acts as a lever arm that transfers movements to the 1st valvula. The posterior T9-2nd valvifer muscle and the small 1st-valvifer-genital membrane muscle stabilize the system during oviposition.Conclusions: From our examination of the elements of the musculoskeletal ovipositor system of ichneumonids, we discussed leverages and muscle forces and developed a functional model of the underlying working mechanisms adding to our understanding of a key feature that has largely determined the evolutionary success of the megadiverse Ichneumonidae with more than 24,000 hitherto described species.