Localization of rDNA sites in holocentric chromosomes of three species of triatomines (Heteroptera, Triatominae).
Chromatin organization in the holocentric chromosomes of three triatomines species was cytologically studied by fluorescent in situ hybridization with a 45S rDNA probe of Drosophila melanogaster to localize ribosomal genes. In Triatoma tibiamaculata, metaphases I showed telomeric highlights in a single, larger bivalent. In T. protacta, hybridization was detected in one of the telomeres of an autosomal chromosome. In T. platensis, there were highlights in a single, smaller chromosome (X chromosome). The results obtained did not agree with the expected localization of rDNA genes in the sex chromosomes of triatomines, as demonstrated by silver impregnation, and suggest that the chromosome reorganization that occurred in this group during evolution may be a more important mechanism involved in rDNA distribution.
Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, IBILCE-UNESP, 15054-000 São José do Rio Preto, SP, Brasil. grazielaguiar@terra.com.br
Grasiela Dias de Campos
GD
Severi-Aguiar
Maria Tercília Vilela
MT
de Azeredo-Oliveira
D000818:Animals; D002871:Chromosome Banding; D002875:Chromosomes / Q000235:genetics*; D004275:DNA, Ribosomal / Q000032:analysis* / Q000235:genetics; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008677:Metaphase; D009697:Nucleolus Organizer Region; D050809:POU Domain Factors; D013045:Species Specificity; D014225:Triatominae / Q000145:classification / Q000235:genetics*
D004275:DNA, Ribosomal; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D050809:POU Domain Factors; C104121:nub protein, Drosophila