Graduate Program in Entomology, Department of Animal Biology, Federal University of Viçosa, Minas Gerais, CEP: 36570-000, Vicosa, Brazil.
Micron. 2010 Apr;41(3):187-92. doi: 10.1016/j.micron.2009.11.005. Epub 2009 Nov 24.
This study represents the first characterization of male reproductive tracts and ultrastructural description of sperm of Cryptinae species. In Lymeon dieloceri and Pachysomoides sp., the male reproductive tract is formed by a pair of testis, two deferent ducts, two accessory glands and one ejaculatory duct. The spermatozoa are similar to those described for other Hymenoptera, with: (1) the acrosome formed by the acrosomal vesicle covering the perforatorium, which has its base inserted in a cavity located in the nucleus point; (2) a thin nucleus with electron-dense chromatin; (3) an electron-dense centriolar adjunct located between the nucleus and one of the two mitochondrial derivatives; (4) an axoneme with a 9 + 9 + 2 microtubule arrangement; (5) two long mitochondrial derivatives with peripheral cristae and; (6) two accessory bodies located between the two mitochondrial derivatives and the axoneme. These ichneumonids present structural characteristics similar to other parasitic wasps, such as presence of a single follicle per testis, layer of extracellular material enveloping the acrosome and accessory microtubules ending before others in final portion of the flagellum. However, male reproductive system and the spermatozoa presented morphological characteristics that allowed their differentiation, such as oval shapes accessory glands and the symmetric mitochondrial derivatives in L. dieloceri compared to the spherical accessory glands and asymmetrical derivatives observed in Pachysomoides sp. Taken together, data presented here demonstrates that diversity of morphological characteristic from the male reproductive tract and spermatozoa in Hymenoptera might provide a character system that can be used, in association with other systems, to resolve various uncertainties about the evolutionary relationships of this insect group.
这项研究首次对 Cryptinae 物种的雄性生殖道进行了描述，并对精子的超微结构进行了描述。在 Lymeon dieloceri 和 Pachysomoides sp.中，雄性生殖道由一对睾丸、两条输精管、两个附属腺和一条射精管组成。精子与其他膜翅目昆虫描述的相似，具有：（1）由覆盖顶体孔的顶体泡形成的顶体，其基部插入位于核点的腔中；（2）薄的核，染色质电子致密；（3）一个电子致密的中心粒附属物位于核和两个线粒体衍生物之一之间；（4）轴丝具有 9 + 9 + 2 微管排列；（5）两个长的线粒体衍生物具有周围嵴；（6）两个附属体位于两个线粒体衍生物和轴丝之间。这些寄生蜂具有与其他寄生蜂相似的结构特征，例如每个睾丸有一个卵泡，顶体被细胞外物质包裹，附属微管在鞭毛的末端部分比其他微管先结束。然而，雄性生殖系统和精子呈现出形态特征，允许它们进行分化，例如 Lymeon dieloceri 中附属腺体呈椭圆形，线粒体衍生物对称，而在 Pachysomoides sp.中，附属腺体呈球形，线粒体衍生物不对称。综上所述，本文提供的数据表明，膜翅目昆虫雄性生殖道和精子的形态特征多样性可能提供一个特征系统，该系统可以与其他系统一起，解决关于这个昆虫类群进化关系的各种不确定性。
