title: The sperm structure and spermiogenesis of the heteropteran Coptosoma scutellatum (Geoffroy) with emphasis on the development of the centriole adjunct.
abstract: The sperm structure and spermiogenesis of the morphologically peculiar heteropteran Coptosoma scutellatum has been examined with electron microscopy. The sperm has a short monolayer acrosome, a cylindrical nucleus, a 9+9+2 axoneme and two mitochondrial derivatives with crystallized matrix. It shows the synapomorphies typical of the group, consisting of (a) two crystallized areas in the mitochondrial derivatives; (b) the presence of two bridges connecting the intertubular material of the flagellar axoneme to the flattened cisterns adhering to the inner sides of the mitochondrial derivatives; (c) the absence of accessory bodies. The most interesting feature is the presence, in the early spermatid, of an extended centriole adjunct material with the shape of a large ribbon-like structure. This material surrounds the posterior nuclear region and extends anteriorly along the nucleus. It is a microtubule-organizing-center (MTOC) producing the many microtubules surrounding the sperm components At the end of spermiogenesis, the centriole adjunct material modifies into two kidney-like structures accompanying the nuclear posterior end and surrounding the modified centriole.
authors.affiliation: Laboratório de Biologia Estrutural, Departamento de Biologia Geral, UFV, 36570-900 Viçosa, Minas Gerais, Brazil. Electronic address: glendadias1@hotmail.com.
authors.forename: Glenda
authors.initials: G
authors.lastname: Dias
authors.affiliation: Laboratório de Biologia Estrutural, Departamento de Biologia Geral, UFV, 36570-900 Viçosa, Minas Gerais, Brazil. Electronic address: jslinoneto@gmail.com.
authors.forename: José
authors.initials: J
authors.lastname: Lino-Neto
authors.affiliation: Dipartimento di Scienze della Vita, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy. Electronic address: david.mercati@unisi.it.
authors.forename: David
authors.initials: D
authors.lastname: Mercati
authors.affiliation: Dipartimento di Scienze della Vita, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy. Electronic address: romano.dallai@unisi.it.
authors.forename: Romano
authors.initials: R
authors.lastname: Dallai
mesh_terms: D000177:Acrosome / Q000648:ultrastructure; D000818:Animals; D054468:Axoneme / Q000648:ultrastructure; D002502:Centrioles / Q000502:physiology* / Q000648:ultrastructure; D005407:Flagella / Q000648:ultrastructure; D020062:Heteroptera; D008297:Male; D046529:Microscopy, Electron, Transmission; D008870:Microtubules / Q000648:ultrastructure; D008928:Mitochondria / Q000648:ultrastructure; D013087:Spermatids / Q000648:ultrastructure; D013091:Spermatogenesis; D013094:Spermatozoa / Q000166:cytology*
keywords: Heteroptera; Insect spermiogenesis; MTOC and Centriole adjunct; Sperm structure