Análises moleculares em Melipona rufiventris e Melipona mondury (Hymenoptera: Apidae)

• Autor(a) principal: Lopes, Denilce Meneses
• Data de Publicação: 2008
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/231
• topic: Hymenoptera; Microssatélites; Cytb; Citometria de fluxo; Hymenoptera; Microsatellites; Cytb; Flow cytometry; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

Melipona mondury and M. rufiventris are two species of indigenous stingless bees which are very similar morphologically. Studies carried out with those species and different kinds of molecular markers revealed low genetic variability. Besides, populations of some regions revealed patterns which suggest that more than one species are receiving the same scientific name. Today, however, several methodologies make it possible to differentiate species and evaluate the genetic structure and the genic flow, besides supplying the basis for the understanding of other important aspects such as the genome evolution of different groups and organisms. So, in this work, it was tried to optimize tools that could help populational and evolutionary studies of the two mentioned species, which could also be used with other bee species. In order to achieve this, several methodologies were used: (1) the drawing of primers microsatellites for Melipona mondury and M. rufiventris and the evaluation of their amplification in other stingless bee species; (2) comparison between the polymorphism found with the specific primers and that of the heterologous primers; (3) analysis of the cytochrome B sequence and (4) standardization of the flow cytometry protocol, in order to determine the DNA content of bees and its use on M. rufiventris, M. mondury and Scaptotrigona xantrotricha. Using the ISSR technique, it was possible to achieve the drawing of 10 primers microsatellites for M. rufiventris and 11 for M. mondury, which presented the following genetic diversity values: H=0,47 and H=0,38, respectively. Those values were higher than those observed in amplifications in which it was used primers drawn for M. bicolor (H=0,16 and H=0,18 for M. mondury and M. rufiventris, respectively). In the analysis of cytochrome B sequences, eleven haplotypes were found which allowed the separation of three different groups, showing that could there are more than one species in these regions. Finally, the standardized methodology for the determination of the bee DNA content furnished good quality histograms, with variation coefficient values of 2,87-4,14%. It demonstrates the usefulness of this methodology in studies involving bees. The DNA 1C content values found for females of M. rufiventris, M. mondury and S. xantotricha were C = 0.93 pg, C = 0,95 pg and C = 0,44 pg, respectively, which reveals that the size of the genome of the two species of Melipona was about twice the size of the one belonging to S. xantotricha. This variation may show differences in the genomic structure of the species analyzed. However, further studies should be carried out to investigate the genome of other species of Melipona and other genders of stingless bees, in order to verify the processes involved in the expansion and contraction of their genomes.