title: The sperm ultrastructure and spermiogenesis of Tribolium castaneum (Coleoptera: Tenebrionidae) with evidence of cyst degeneration.
abstract: Previous studies on the spermatogenesis of tenebrionid beetles showed the unusual formation of two antiparallel sperm bundles per cyst. In this work we reported this feature also in Tribolium castaneum using light and transmission electron microscopy. The sperm structure of T. castaneum, similar to other tenebrionids, consists of a three-layered acrosome, an elongated nucleus and a flagellum with a 9+9+2 axoneme, two accessory bodies and two asymmetric mitochondrial derivatives. The presence of two antiparallel sperm bundles per cyst also in Meloidae and Rhipiphoridae suggests that it is a strong trait synapomorphic for Tenebrionoidea. The huge degeneration of whole sperm cells in several cysts of testes during spermiogenesis is also described.
authors: Laboratório de Biologia Estrutural, Departamento de Biologia Geral, UFV, 36570-900 Viçosa, Minas Gerais, Brazil; Dipartimento Scienze della Vita, Università degli Studi di Siena, Via Aldo Moro 2, 53100 Siena, Italy. Electronic address: glendadias1@hotmail.com.
authors: Glenda
authors: G
authors: Dias
authors: Laboratório de Biologia Estrutural, Departamento de Biologia Geral, UFV, 36570-900 Viçosa, Minas Gerais, Brazil. Electronic address: jslinoneto@gmail.com.
authors: José
authors: J
authors: Lino-Neto
authors: Dipartimento Scienze della Vita, Università degli Studi di Siena, Via Aldo Moro 2, 53100 Siena, Italy. Electronic address: david.mercati@unisi.it.
authors: David
authors: D
authors: Mercati
authors: Dipartimento Scienze della Vita, Università degli Studi di Siena, Via Aldo Moro 2, 53100 Siena, Italy. Electronic address: romano.dallai@unisi.it.
authors: Romano
authors: R
authors: Dallai
mesh_terms: D000177:Acrosome / Q000648:ultrastructure; D000818:Animals; D054468:Axoneme / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D003560:Cysts / Q000648:ultrastructure; D008297:Male; D046529:Microscopy, Electron, Transmission; D008859:Microscopy, Polarization; D010641:Phenotype; D013082:Sperm Tail / Q000648:ultrastructure; D013091:Spermatogenesis; D013094:Spermatozoa / Q000648:ultrastructure*; D014231:Tribolium / Q000502:physiology* / Q000648:ultrastructure*
keywords: Electron microscopy; Sperm degeneration; Sperm structure; Tenebrionids