Spermiogenesis in three species of cicadas (Hemiptera: Cicadidae)
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H , Sanborn, Allen F , Phillips, Polly K F
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6865 , http://hdl.handle.net/10962/d1011207
- Description: Spermiogenesis in three species of cicadas representing one cicadettine (Monomatapa matoposa Boulard) and two cicadines (Diceroprocta biconica [Walker] and Kongota punctigera [Walker]) was investigated by light and electron microscopy. Although spermiogenesis was occurring in the testis of adult males of all species, earlier spermiogenic stages were observed in D. biconica only. While spermiogenesis was similar to that described for other insects, some differences were noted. For example granular material did not assemble around the centriole to form a centriolar adjunct but did accumulate in the cytoplasm of early spermatids adjacent to a region of the nuclear membrane where nuclear pores were aggregated. In late spermatids this material accumulated anterior to the mitochondrial derivatives in a developing postero-lateral nuclear groove. While this material has been named the ‘centriolar adjunct’ by previous authors, its formation away from the centriole raises questions about its true identity. Second, during acrosome maturation an ante-acrosomal region of cytoplasm develops. Although present in later spermatids, this region is lost in spermatozoa. Interspecific variations in chromatin condensation patterns and the number of microtubule layers encircling the spermatid nucleus during spermiogenesis were noted.
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- Date Issued: 2007
Sperm morphology in five species of cicadettine cicadas (Hemiptera: Cicadomorpha: Cicadidae)
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6930 , http://hdl.handle.net/10962/d1011948
- Description: Mature spermatozoa from five species of cicadas of the subfamily Cicadettinae (Quintilia wealei, Melampsalta leucoptera, Stagira simplex, Xosopsaltria thunbergi and Monomatapa matoposa) were examined by light and electron microscopy. In each species sperm are elongate, aggregated into organized bundles with their heads embedded in a homogenous matrix to form spermatodesmata, and exhibit polymegaly. The head of the sperm consist of an anteriorly positioned conical acrosome that has a tubular substructure and a deep, posterior invagination that forms the subacrosomal space (eccentrically positioned anteriorly). The acrosome is flattened anteriorly; posteriorly it extends along either side of the nucleus as two tubular processes that gradually decrease in diameter. The filiform nucleus tapers anteriorly and intrudes into the subscrosomal space. Posteriorly the nucleus has a lateral invagination that houses material of the so-called centriolar adjunct. Posterior to the centriolar adjuct and the nucleus are two crystalline mitochondrial derivatives and a centriole, respectively, the latter giving rise to the axoneme, which has a 9 + 9 + 2 arrangement of microtubules. In these respects the sperm are similar to those of platypleurine cicadas. However, some features seem unique to cicadettines, including the structural organization of an enlarged centriolar adjunct and the dimensions of the tails. The enlarged centriolar adjunct has a lamella-like substructure and can be considered a synapomorphic character in the Cicadettinae. It is, therefore, potentially useful in the separation of this subfamily from the Cicadinae. In addition, the great length of the sperm nucleus of long-headed sperm in M. matoposa could be a synapomorphy of this genus and related taphurine and cicadettine species.
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- Date Issued: 2006
Sperm morphology in four species of African platypleurine cicadas (Hemiptera: Cicadomorpha: Cicadidae)
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6917 , http://hdl.handle.net/10962/d1011880
- Description: Mature spermatozoa from four species of platypleurine cicadas (Albanycada albigera, Azanicada zuluensis, Platypleura capensis and P. hirtipennis) were examined by light and electron microscopy. The filiform sperm have a similar ultrastructure in all species but notable variations were found in sperm dimensions. All species produce more than one discrete length of nucleated, motile sperm, a form of polymorphism termed polymegaly. Polymegaly is expressed in two ways: sperm have bi- or trimodal head and tail lengths. The anterior parts of sperm heads are embedded in an elongate homogenous matrix forming a spermatodesm. The conical acrosome is deeply invaginated posteriorly, and sits on top of the nucleus. The acrosomal contents are differentiated internally with an electron-lucent central medulla and a denser cortex. The homogenously electron-dense nucleus is pointed anteriorly and is generally cylindrical, although posteriorly there is a lateral invagination that extends part-way along the nucleus. This invagination houses fine granular material of the centriolar adjunct. Vesicle-like elements that are associated with both the posterior nucleus and the centriolar adjunct are also found within the invagination. Immediately posterior of and adjoining the centriolar adjunct is a pair of mitochondrial derivatives that are elongated and extend for almost the entire length of the tail. The absence of accessory bodies in cicada sperm suggests that within the Cicadomorpha, the families Cicadidae and Cercopidae are closely affiliated.
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- Date Issued: 2005