Reavaliação dos valores de conteúdo de DNA dos padrões de referência internacionalmente utilizados em quantificações genômicas de plantas

• Ano de defesa: 2009
• Autor(a) principal: Praça, Milene Miranda
• Orientador(a): Carvalho, Carlos Roberto de
• Banca de defesa: Cruz, Cosme Damião , Caixeta, Eveline Teixeira
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Citometria de fluxos; citometria de imagem; Quantificação de DNA; Valor 2C
• Palavras-chave em Inglês: Flow cytometry; Image cytometry; DNA amounts; 2C values
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/1302

The application of flow (FC) and image (IC) cytometry techniques have enabled the genome characterization of various plant species. Such works have provided relevant information for evolution and molecular studies, and for plant breeding. In order to quantify the DNA of a species, standard references with well-established DNA content are necessary. However, it can be observed that the species used as standard are described with different DNA values in the literature, which has caused inaccurate genome measurement of various plant species. Considering the importance of establishing standards for cytometric analyses in plants, in view of the disparate values cited in the literature for the some specie, the present study aimed at reassessing the DNA content values of some of the standard references mostly used worldwide. For this purpose, the species Raphanus sativus L., Solanum lycopersicum L., Glycine Max (L.) Merr., Zea mays L., Pisum sativum L., Vicia faba L. and Allium cepa L. were cytometrically compared among themselves, and with Arabidopsis thaliana (L.) Heynh. and Drosophila melanogaster Meig., which are species with known genome sequences. CVs below 4.46% and 4.97% showed that FC and IC methodologies were properly employed. At first, plant standards were compared pairwise, and it was observed that the measured DNA amounts were different than those previously described. After these comparisons, the DNA content was calculated for all standards, based on the index, using each one as a primary reference standard. There was no conformity between the obtained results and the values described previously. However, through multivariate analyses using the data obtained by FC, similarity was detected between these results and the reference values found in the literature. When the data was compared with the results found by the different laboratories researched by Dolezel et al. (1998), it could be observed that they constituted groups with the laboratories that used the same primary standard of methodology. When compared only to the DNA values obtained at the present study, by the Dunnett test, it was noticed that R. sativus and D. melanogaster provided the largest number of differences in relation to the reference values. These results were corroborated by the IC data. The other species supplied the same number of similarities. This way the newly rendered values, especially that of A. thaliana, whose DNA has been sequenced, could form a group of plant Gold standards .