黄眶离缘姬蜂卵巢和毒液器官的形态学及其超微结构

Morphology and ultrastructure of the ovary and venom apparatus of endoparasitoid Trathala flavo-orbitalis Cameron

本文观察了内寄生蜂黄眶离缘姬蜂Trathala flavo-orbitalis Cameron卵巢和毒液器官的形态及超微结构,为了解黄眶离缘姬蜂与其寄主之间的协同进化关系奠定基础。在光学显微镜下解剖雌性生殖系统,并结合透射电镜进行形态学及超微结构观察,结果表明黄眶离缘姬蜂毒液器官主要由一个薄壁的毒囊、两条接于毒囊顶端的毒腺、通向产卵器的毒液导管组成。毒腺由分泌细胞层和环腔的内膜构成,分泌细胞层中存在大量的端器,主要功能是分泌毒液。毒囊由肌肉鞘层、扁平细胞层以及内膜层组成,肌肉鞘内肌纤丝规则排列,扁平细胞层内的细胞器极其稀少,内膜呈波浪状均匀加厚。黄眶离缘姬蜂的一对卵巢分别由8条卵巢小管组成,开口于两条侧输卵管,在卵巢与侧输卵管相接处略微膨大形成卵巢萼区,萼区内存在大量类似姬蜂病毒的颗粒。黄眶离缘姬蜂的毒液器官属于II型毒液器官,是较高等的进化模式,其毒液器官的形态结构与雌蜂的产卵行为相关。在萼区内发现的类似姬蜂病毒的颗粒,对研究寄生蜂调控寄主的免疫和发育生理具有重要意义。

To better understand the coevolution relationship between Trathala flavo-orbitalis Cameron and its host, we observed the morphology and uhrastructure of the ovary and venom apparatus of the endoparasitoid Trathalaflavo-orbitalis Cameron （Hymenoptera： Ichneumonidae） by dissecting the female reproductive system and then examined using optical microscope and transmission electron microscope. The venom apparatus of T. flavo-orbitalis includes one venom reservoir, one venom duct which leads to the ovipositor and two gland filaments which join together on the top of the venom reservoir. An outer single layer of secretory cells and an inner intima lined the lumen were observed in the gland filaments. Secretory cells contain some end apparatus, which secreted venom. The reservoir consists of a muscular sheath, epithelial cell, and intima layer. The muscular fibers are finely organized. No distinct organelles are observed in epithelial cell. The intima is thickened uniformly. A pair of ovaries is found in T. flavo-orbitalis and approximately eight ovarioles are observed in each ovary which connects with a lateral oviduct via a small calyx region. In addition, a lot of ichnovirus-like particles are found in the calyx region. The venom apparatus of T. flavo-orbitalis belongs to Type II. Some ichnovirus-like particles are discovered in the calyx cell, which would be significant to study how wasps regulate the immune system and developmental physiology of the host.