Agradecimentos: This research was supported by the São Paulo State Research Foundation (FAPESP, Brazil; grant no. 2015/10356-2) and the Brazilian National Council for Research and Development (CNPq, grant no. 304668/2014-1). The funders had no role in study design, data collection and analysis,...

Agradecimentos: This research was supported by the São Paulo State Research Foundation (FAPESP, Brazil; grant no. 2015/10356-2) and the Brazilian National Council for Research and Development (CNPq, grant no. 304668/2014-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. C.H.L.I. received a fellowship from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil - Finance Code 001). M.L.S.M. received a fellowship from CNPq (grant no. 304668/2014-1)

Abstract: Constitutive heterochromatin typically exhibits low gene density and is commonly found adjacent or close to the nuclear periphery, in contrast to transcriptionally active genes concentrated in the innermost nuclear region. In Triatoma infestans cells, conspicuous constitutive...

Abstract: Constitutive heterochromatin typically exhibits low gene density and is commonly found adjacent or close to the nuclear periphery, in contrast to transcriptionally active genes concentrated in the innermost nuclear region. In Triatoma infestans cells, conspicuous constitutive heterochromatin forms deeply stained structures named chromocenters. However, to the best of our knowledge, no information exists regarding whether these chromocenters acquire a precise topology in the cell nuclei or whether their 18S rDNA, which is important for ribosome function, faces the nuclear center preferentially. In this work, the spatial distribution of fluorescent Feulgen-stained chromocenters and the distribution of their 18S rDNA was analyzed in Malpighian tubule cells of T. infestans using confocal microscopy. The chromocenters were shown to be spatially positioned relatively close to the nuclear periphery, though not adjacent to it. The variable distance between the chromocenters and the nuclear periphery suggests mobility of these bodies within the cell nuclei. The distribution of 18S rDNA at the edge of the chromocenters was not found to face the nuclear interior exclusively. Because the genome regions containing 18S rDNA in the chromocenters also face the nuclear periphery, the proximity of the chromocenters to this nuclear region is not assumed to be associated with overall gene silencing

Resumo:

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

2015/10356-2

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

304668/2014-1; 304668/2014-1

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

001

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