title: Molecular characterization of constitutive heterochromatin in three species of Trypoxylon (Hymenoptera: Crabronidae: Trypoxylini) by CMA3/DAPI staining.
abstract: Previous cytogenetic analyses in Trypoxylon Latreille, 1796 have been basically restricted to C-banding. In the present study, base-specific CMA3 and DAPI fluorochrome staining were used to characterize the constitutive heterochromatin in three Trypoxylon species. The heterochromatin was GC-rich in all the species studied; however, in Trypoxylon nitidum F. Smith, 1856the molecular composition of the heterochromatinwasdifferent among chromosome pairs. Conversely, the euchromatin was AT-rich in the three species. These results suggest high conservatism in the euchromatic regions as opposed to the heterochromatic regions that have a high rate of changes. In this study, we report the karyotype of Trypoxylon rugifrons F. Smith, 1873which has the lowest chromosome number in the genus and other characteristics of the likely ancestral Trypoxylon karyotype.
authors.affiliation: Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz. Rod Ilhéus/Itabuna Km 16, 45650-000 Ilhéus, Bahia, Brazil.
authors.forename: Rodolpho Santos Telles
authors.initials: RS
authors.lastname: Menezes
authors.forename: Antonio Freire
authors.initials: AF
authors.lastname: Carvalho
authors.forename: Janisete Gomes
authors.initials: JG
authors.lastname: Silva
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Costa
keywords: CMA3/DAPI; Comparative cytogenetics; heterochromatin