Sperm ultrastructure of the honey bee (Apis mellifera) (L) (Hymenoptera, Apidae) with emphasis on the nucleus-flagellum transition region

Abstract

The flagellum of Apis mellifera (Hymenoptera, Apidae) consists of two mitochondrial derivatives, an axoneme and two accessory bodies. The mitochondrial derivatives are of unequal size and lie parallel to the axoneme. In the larger derivative four regions can be distinguished while in the smaller, only three. The region occurring only in the larger derivative consists of paracystalline material. The smaller mitochondrial derivative terminates anterior to the larger one. An extremely long centriolar adjunct is observed between the nucleus and the smaller mitochondrial derivative. This adjunct is compact, very electron dense and gradually tapers from base toward apex, finishing at the anterior extremity of the axonemal microtubules. In this flagellar region, there is only one accessory body present between the larger mitochondrial derivative and the axoneme. Anteriorly, the tips of the axonemal microtubules are inserted in a well developed mass of granular appearance. This material surrounds the nuclear base, separating it from the anterior end of the larger mitochondrial derivative. We believe that the structure identified here as a centriolar adjunct is homologous to that observed in Formicidae, Ichneumonoidea and Symphyta. Therefore, very probably, it is common to most Hymenoptera.

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

“…Furthermore, the mitochondrial regions in H. foveolatum are very similar to those described for other Apoidea ( Lino-Neto et al, 2000b;Zama et al, 2001, Zama et al, 2004, Zama et al, 2005a, Zama et al, 2005b, Araújo et al, 2005and Fiorillo et al, 2005.…”

“…The structure of the H. foveolatum spermatozoa is similar to the general description for insect sperm ( Quicke et al, 1992, Newman and Quicke, 1998, Newman and Quicke, 1999a, Newman and Quicke, 1999b, Newman and Quicke, 2000, 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, Báo et al, 2004and Fiorillo et al, 2005. They are linear, long and slender as which is observed for the majority of the Hymenoptera.…”

“…The nuclear base penetrating into the beginning of the axoneme has also been observed in Apinae (Peng et al, 1993 andLino-Neto et al, 2000b) and Vespidae (Mancini et al, 2006). However, it is uncommon for the vast majority of Apoidea, which have the nuclear base finishing in a short cone above the axonemal implantation (Zama et al, 2001, Zama et al, 2004, Zama et al, 2005a, Zama et al, 2005b, Báo et al, 2004and Fiorillo et al, 2005.…”

“…The asymmetry in length and diameter of the mitochondrial derivatives is common for most Apoidea (Lino-Neto et al, 2000b;Zama et al, 2001, Zama et al, 2004, Zama et al, 2005a, Zama et al, 2005b, Báo et al, 2004and Fiorillo et al, 2005, Vespidae (Mancini et al, 2006), and some Symphyta (Newman and Quicke, 1999a). Furthermore, the mitochondrial regions in H. foveolatum are very similar to those described for other Apoidea ( Lino-Neto et al, 2000b;Zama et al, 2001, Zama et al, 2004, Zama et al, 2005a, Zama et al, 2005b, Araújo et al, 2005and Fiorillo et al, 2005.…”

“…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.…”