Morphology of testicular and post-testicular spermatozoa in Microstigmus arlei Richards, 1972 and M. nigrophthalmus Melo, 1992 (Hymenoptera: Apoidea: Pemphredoninae) with phylogenetic consideration

Abstract

The sperm of Microstigmus arlei and Microstigmus nigrophthalmus are twisted in a spiral and consist of two regions: the head, formed by an acrosome and a nucleus, and the flagellum, formed by two asymmetric mitochondrial derivatives, a long centriolar adjunct, an axoneme (9 + 9 + 2) and two accessory bodies. The head shows a characteristic morphology. The acrosome is very long and is basically made up of a paracrystalline structure. In the central head region, the acrosome is inserted into the nucleus, which is observed coiling laterally around the paracrystalline structure. In the subsequent part of the spermatozoon the nucleus appears round in transverse sections, and over some length it is still penetrated by the acrosome until shortly distal to the flagellar insertion. At this point the nucleus forms an inverted cone-shaped projection. These morphological characteristics of acrosome and nucleus of the Microstigmus wasp have not been previously described in Apoidea and are useful for phylogenetic evaluation of this superfamily.

Structural and ultrastructural characterization of male reproductive tracts and spermatozoa in fig wasps of the genus Pegoscapus (Hymenoptera, Chalcidoidea)

“…Indeed, some recent studies have demonstrated that the structure and ultrastructure of spermatozoa of Chalcidoidea furnish sufficient variations to provide additional characters for cladistic analysis (Hogge and King, 1975, Quicke et al, 1992, Lino-Neto et al, 1999, Lino-Neto et al, 2000aand Lino-Neto and Dolder, 2001b, in accordance with other works addressing the sperm ultrastructure of varied Hymenoptera (Dallai and Afzelius, 1995, Jamieson et al, 1999, Lino-Neto et al, 2000b, Lino-Neto and Dolder, 2001a, Lino-Neto and Dolder, 2002, Zama et al, 2001, Zama et al, 2004, Zama et al, 2007, Báo et al, 2004, Araújo et al, 2005band Fiorillo et al, 2005.…”

“…In all Aculeata, the central microtubules and the nine doublets terminate first, followed by the accessory microtubules (Lino-Neto et al, 2000b, Zama et al, 2001, Zama et al, 2004, Zama et al, 2007, Báo et al, 2004, Araújo et al, 2005b, Fiorillo et al, 2005and Mancini et al, 2006 although they all terminate approximately together in ants (Wheeler et al, 1990 andDolder, 2002). In the Parasitica the nine doublets are the last microtubules to be lost at the flagellum tip (Newman and Quicke, 1998, Lino-Neto et al, 1999, Lino-Neto et al, 2000aand Lino-Neto and Dolder, 2001b.…”

Morphology of the male reproductive system and spermiogenesis in Hypanthidium foveolatum (Alfken, 1930) (Hymenoptera: Apidae: Megachilinae)

“…The arrangement observed in the axoneme with 9 + 9 + 2 microtubules is the pattern for Aculeata with the central microtubules and the nine doublets terminating first, followed by the accessory microtubules (Lino-Neto et al, 2000b, Zama et al, 2001, Zama et al, 2004, Zama et al, 2005a, Zama et al, 2005b, Zama et al, 2007, Báo et al, 2004, Araújo et al, 2005, Fiorillo et al, 2005and Mancini et al, 2006. Based on the characteristics compared above, the spermatozoa of H. foveolatum are, for the most part, similar to the majority of the Hymenoptera ( Jamieson et al, 1999).…”

“…The cystic organization of spermatogonial lineage cells is also common for Hymenoptera ( Cruz-Landim, 2001). However, the number of spermatids per cyst varies among different species depending on the number of spermatogonial premeiotic divisions ( Oguma et al, 1987, Quagio-Grassioto and Lello, 1996, Cruz-Landim, 2001and Zama et al, 2007.…”

“…Some recent studies have demonstrated that the structure and ultrastructure of spermatozoa in Hymenoptera furnish sufficient variations to provide additional characters for cladistic analysis (Quicke et al, 1992, Dallai and Afzelius, 1995, Lino-Neto et al, 1999, Lino-Neto et al, 2000a, Lino-Neto et al, 2000b, Lino-Neto and Dolder, 2001a, Lino-Neto and Dolder, 2001b, Lino-Neto and Dolder, 2002, Zama et al, 2001, Zama et al, 2004, Zama et al, 2005a, Zama et al, 2005b, Zama et al, 2007, Báo et al, 2004, Araújo et al, 2005and Fiorillo et al, 2005 as has been shown possible in other groups of insects (Baccetti, 1987 andJamieson et al, 1999). The study of spermiogenesis can also provide new characters for improving the accuracy of hypotheses on phylogenetic relationships.…”