Structural and ultrastructural characteristics of male reproductive tract and spermatozoa in two Cryptinae species (Hymenoptera: Ichneumonidae)

Abstract

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.

Morphological aspects of testes and sperm ultrastructure in the “symphyta” Digelasinus diversipes kirby 1882 (hymenoptera: Argidae: Dielocerinae)

“…Many similar morphological characteristics associated with the male reproductive system were found in comparative studies on the Hymenoptera (Araú jo et al., 2005a,b, 2009Brito et al, 2005;Bushrow et al, 2006;Dallacqua and Cruz-Landim, 2003;Damiens and Boivin, 2005;Ferreira et al, 2004;Fiorillo et al, 2008Fiorillo et al, , 2009Moreira et al, 2008Moreira et al, , 2010. On the other hand, these studies also identified several features that differed between the various groups.…”

“…In Formicidae, the number of follicles ranges from 1 to 25 (Wheeler and Krutzsch, 1992). A single follicle was found in each testis in some species of parasitic wasps (Fiorillo et al, 2008;Moreira et al, 2010), whereas in D. diversipes, there is 22 follicles. There are no reports in the literature for any of the other species of ''symphyta.…”

Ultrastructure and heteromorphism of spermatozoa in five species of bugs (Pentatomidae: Heteroptera)

“…In some groups, sperm size and morphology even vary among related species (Immler et al, 2007;Pitnick et al, 2009). Franzén (1970) and Wirth (1984) suggested the potential value of sperm morphology for phylogenetic studies on invertebrates, a group in which the highest diversity of these cells has been observed (Araújo et al, 2009(Araújo et al, , in press, 2010Levron et al, 2010;Moreira et al, 2010;Paccagnini et al, 2010).…”

Morphology of the male reproductive system and spermatozoa in Centris Fabricius, 1804 (Hymenoptera: Apidae, Centridini)

“…that described in several other Hymenoptera species (Dirks and Sternburg, 1972;Dallacqua and Cruz-Landim, 2003;Ferreira et al, 2004;Bushrow et al, 2006;Fiorillo et al, 2008Fiorillo et al, , 2009Gracielle et al, 2009;Araújo et al, 2010a, b;Moreira et al, 2008Moreira et al, , 2010.…”

“…In insects, including Hymenoptera, characteristics obtained from the spermatozoa structure are used in phylogenetic studies (Baccetti, 1970;Dallai, 1974;Jamieson, 1987;Quicke et al, 1992;Jamieson et al, 1999). The morphology of the Hymenoptera spermatozoa is known in various groups Quicke, 1999a, b, 2000;Lino-Neto et al, 1999, 2000aLino-Neto and Dolder, 2001b;Zama et al, 2005bZama et al, , 2007Mancini et al, 2006Mancini et al, , 2009Moya et al, 2007;Brito et al, 2009;Araújo et al, 2010a, b;Moreira et al, 2010;Oliveira et al, 2010). In bees, the most detailed studies are restricted to the Apidae (Lino-Neto et al, 2000b;Zama et al, 2001Zama et al, , 2004Zama et al, , 2005aBáo et al, 2004;Araújo et al, 2005c;Badke et al, 2005;Fiorillo et al, 2009), some Halictidae (Fiorillo et al, 2005), Megachilidae and Andrenidae (Quicke et al, 1992).…”