title: Short Communication A small B chromosome in the grasshopper Ommexecha virens (Ommexechidae).
abstract: B chromosomes, also called supernumerary or accessory chromosomes, have been characterized as extra elements found in the karyotypes of different eukaryotic species. B chromosomes are nonvital and only occur in some individuals within a species. Moreover, the chromosomes contain silenced genes, and they exhibit heterochromatinization and the accumulation of repetitive DNA and transposons. In the present study, we describe an extra chromosome in the grasshopper Ommexecha virens for the first time, using conventional staining and fluorescent in situ hybridization techniques, and we discuss the possible origin of the B chromosome.
authors.affiliation: Laboratório de Experimentação em Drosophila, Departamento de Genética, Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: T E
authors.initials: TE
authors.lastname: Souza
authors.affiliation: Laboratório de Genética e Citogenética Animal, Departamento de Genética, Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: L C
authors.initials: LC
authors.lastname: Silva-Neto
authors.affiliation: Laboratório de Experimentação em Drosophila, Departamento de Genética, Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: J F
authors.initials: JF
authors.lastname: Santos
authors.affiliation: Laboratório de Genética e Citogenética Animal, Departamento de Genética, Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: V
authors.initials: V
authors.lastname: Loreto
authors.affiliation: Laboratório de Experimentação em Drosophila, Departamento de Genética, Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: T T
authors.initials: TT
authors.lastname: Rieger
mesh_terms: D000818:Animals; D059006:Chromosomes, Insect / Q000235:genetics*; D006110:Grasshoppers / Q000235:genetics*; D006570:Heterochromatin / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype
chemical_list: D006570:Heterochromatin