Full text
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| Author(s): |
Daniela Silvestre
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2002-04-15 |
| Examining board members: |
Maria Cristina Arias;
Francisco Gorgonio da Nobrega;
Gonçalo Amarante Guimarães Pereira
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| Advisor: | Maria Cristina Arias |
| Abstract | |
The complete sequence of the mitochondrial genome of a species may help on restriction mapping and to design PCR primers. These can be useful to amplify and sequence specific regions from other species and analyze populations, in phylogenetic and demographic studies. So far, there was reported on literature the mtDNA complete sequence for only one hymenopteran, Apis mellifera, endemic from the Old World. No mitocondrial genome of a Brazilian native bee was ever described. With the increasing devastation of natural environments, several bee species can be led to extinction, including those poorly studied and maybe some unknown species. The meliponines (stingless bees) include key species to several Brazilian ecosystems, so they play an important ecological role. In this project, we have PCR amplified and sequenced 77% of the mitochondrial genome of the stingless bee Melipona bicolor (Apidae, Meliponini). The sequenced region contains all of the 13 mitochondrial protein-coding genes, 18 of 22 tRNA genes, and both rRNA genes (one of them was only partially sequenced). Besides sequencing, this work consisted of: analysis of genome organization (gene content and order); analysis of gene translation and genetic code; analysis of other molecular features (base frequencies, codon usage, gene initiation and termination, amino acid frequencies etc.); and comparison of the characteristics mentioned above with A. mellifera mitocondrial genome and also other insects. The highly biased A+T content is a typical characteristic of A. mellifera mitochondrial genome, and it is even more extreme on M. bicolor mtDNA. There are length and compositional differences on genes between M. bicolor and A. mellifera. At least nine gene order rearrangements were observed by comparing the mtDNA of these species, what is a rare event on closely related organisms. Considering that both species share an intriguing behavior, eusociality, these gene rearrangements may be used as an excellent marker to study the origin and evolution of that behavior on bees. (AU) | |