Grasiela Dias de Campos Severi-Aguiar, Maria Tercília Vilela de Azeredo-Oliveira
Published November 29, 2005
Genet. Mol. Res. 4 (4): 704-709 (2005)

About the Authors
Grasiela Dias de Campos Severi-Aguiar, Maria Tercília Vilela de Azeredo-Oliveira

Corresponding author
G.D.C. Severi-Aguiar
Email: grazielaguiar@terra.com.br

ABSTRACT

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.

Key words: Fluorescent in situ hybridization, Holocentric chromosomes, Nucleolar organizer region, Heteroptera, Triatominae.