Use este identificador para citar ou linkar para este item: http://repositorio.ufla.br/jspui/handle/1/10615
Título: “Sítios frágeis” espontâneos e induzidos nos cromossomos de espécies do complexo Lolium-Festuca
Título(s) alternativo(s): Spontaneous and induced “Fragile sites" in the chromosomes of the Lolium-Festuca complex
Autores: Techio, Vânia Helena
Mittelmann, Andréa
Santos, João Bosco dos
Vieira, Larissa Fonseca Andrade
Torres, Giovana Augusta
Campos, José Marcello Salabert de
Palavras-chave: rDNA 45S
Gramíneas forrageiras
Estabilidade genômica
Quebras cromossômicas
Raio-X
Forage grasses
Genomic stability
Lolium-Festuca complex
Chromosome breakage
X-ray
Data do documento: 23-Nov-2015
Editor: Universidade Federal de Lavras
Citação: ROCHA, Laiane Corsini. Sítios frágeis espontâneos e induzidos nos cromossomos de espécies do complexo Lolium-Festuca. 2015. 86 p. Tese (Doutorado em Genética e Melhoramento de Plantas)-Universidade Federal de Lavras, Lavras, 2015.
Resumo: The fragile sites (FSs) are considered weak regions of the genome and may be prone to form lesions or chromosomal breaks in addition to being related to instability in the human genome, other animals, fish, and yeast. In plants, these sites have been described in some species of grasses such as the genus Lolium, taking place in the sites of 45S rDNA. However, the consequences of fragile sites in the genome of plants are not well-known. Thus, the aims of this study were to evaluate if there is instabilityin the genome of species of Lolium-Festuca complex with spontaneous expression of FSs and through the induction of chromosomal breaks by ionizing radiation and also to check if the genome is recovering from these induced breaks through the synthesis of new telomere. The results showed that the weakened regions in 45S rDNA sites does not present neocentromeric activity, but showed thin and long chromatin fibers, not visible with DAPI staining, connecting the acentric chromosome fragments to chromosome region containing the centromere, not promoting instability in the genome of these species. The same was observed for the species of F. arundinaceae Festulolium hybrids. Fragile sites are not regions prone to breaks afterirradiation with X-ray and there was no formation of new telomeres during the evaluation of cmetaphase.
URI: http://repositorio.ufla.br/jspui/handle/1/10615
Aparece nas coleções:Genética e Melhoramento de Plantas - Doutorado (Teses)

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