Cytogenetic characterization reveals differences in nuclear organization of cystic cells among Brazilian species of Triatoma (Heteroptera, Reduviidae)

Authors

  • Vanessa Bellini Bardella,

    1. Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista UNESPIBILCE, São José do Rio Preto, 15054000, SP, Brazil
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  • Rosana Silistino de Souza,

    1. Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista UNESPIBILCE, São José do Rio Preto, 15054000, SP, Brazil
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  • Juca Abramo Barrera San Martin,

    1. Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina UEL, Londrina, 86051980, PR, Brazil
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  • Célia Guadalupe Tardeli de Jesus Andrade,

    1. Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina UEL, Londrina, 86051980, PR, Brazil
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  • André Luís Laforga Vanzela,

    1. Departamento de Biologia Geral, Centro de Ciências Biológicas, Universidade Estadual de Londrina UEL, Londrina, 86051980, PR, Brazil
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  • Maria Tercília Vilela de Azeredo-Oliveira

    Corresponding author
    1. Departamento de Biologia, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista UNESPIBILCE, São José do Rio Preto, 15054000, SP, Brazil
      (email tercilia@ibilce.unesp.br)
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(email tercilia@ibilce.unesp.br)

Abstract

Cytogenetic studies in triatomines have described the occurrence of holokinetic chromosomes, heterochromatin distribution and the location of rDNA (ribosomal DNA) sites, but few aspects of nuclear organization in this group have been discussed. We have focused on ultrastructural and cytogenetic features and differences in cystic cells of seminiferous tubules between five species of Triatoma. Cystic cells showed evidence of polyploidy events and heterochromatic blocks appeared predominantly in the central region of the nuclei. Cytogenetic analyses showed that there was variation in chromocenter number between species, and that the central regions were AT-rich [DAPI+ (4′,6-diamidino-2-phenylindole+)], whereas the periphery was CG-rich (CMA+). Another characteristic was the distribution of 45S rDNA, which differed according to the chromosomal location of this sequence. In all we have compared aspects of nuclear organization, polyploidy, heterochromatin, rDNA site distribution and methylation levels, as well as the relationships between five species of Triatoma from a cystic cell perspective.

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