title: Physical mapping of 18S rDNA and heterochromatin in species of family Lygaeidae (Hemiptera: Heteroptera).
abstract: Analyses conducted using repetitive DNAs have contributed to better understanding the chromosome structure and evolution of several species of insects. There are few data on the organization, localization, and evolutionary behavior of repetitive DNA in the family Lygaeidae, especially in Brazilian species. To elucidate the physical mapping and evolutionary events that involve these sequences, we cytogenetically analyzed three species of Lygaeidae and found 2n (♂) = 18 (16 + XY) for Oncopeltus femoralis; 2n (♂) = 14 (12 + XY) for Ochrimnus sagax; and 2n (♂) = 12 (10 + XY) for Lygaeus peruvianus. Each species showed different quantities of heterochromatin, which also showed variation in their molecular composition by fluorochrome staining. Amplification of the 18S rDNA generated a fragment of approximately 787 bp. The alignment of the consensus sequence with sequences from other species of Heteroptera deposited in the GenBank revealed a similarity of 98% with small differences. Fluorescent in situ hybridization with the 18S rDNA fragment revealed that this ribosomal gene was located in 1 autosomal pair at different positions in the three species. No cytogenetic data are available for these Brazilian species. The basal number and the possible chromosomal changes that occurred among the different species, as well as the evolution of these DNA sequences, are discussed.
authors.affiliation: Laboratório de Citogenética Animal, Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: V B
authors.initials: VB
authors.lastname: Bardella
authors.affiliation: Laboratório de Citogenética Animal, Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: T R
authors.initials: TR
authors.lastname: Sampaio
authors.affiliation: Laboratório de Citogenética Animal, Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: N B
authors.initials: NB
authors.lastname: Venturelli
authors.affiliation: Laboratório de Citogenética Animal, Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: A L
authors.initials: AL
authors.lastname: Dias
authors.affiliation: Laboratório de Citogenética Animal, Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, PR, Brasil.
authors.forename: L
authors.initials: L
authors.lastname: Giuliano-Caetano
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brasil.
authors.forename: J A M
authors.initials: JA
authors.lastname: Fernandes
authors.affiliation: Laboratório de Citogenética Animal, Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina, Londrina, PR, Brasil renata-darosa@uel.br.
authors.forename: R
authors.initials: R
authors.lastname: da Rosa
mesh_terms: D000818:Animals; D001483:Base Sequence; D002871:Chromosome Banding; D002874:Chromosome Mapping; D059006:Chromosomes, Insect; D005260:Female; D006430:Hemiptera / Q000235:genetics*; D006570:Heterochromatin; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008969:Molecular Sequence Data; D010641:Phenotype; D012337:RNA, Ribosomal, 18S / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
chemical_list: D006570:Heterochromatin; D012337:RNA, Ribosomal, 18S