Estudos moleculares e morfológico em abelhas do gênero Melipona (Hymenoptera)

• Autor(a) principal: Nascimento, Marcilia Aparecida do
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/253
• topic: Estrutura genética; Sensilas; Heterocromatina 1; Gene structure; Sensilla; Heterocromatin 1; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

The genus Melipona is represented by 65 known species of stingless bees distributed in the neotropical regions. Among these species we can find the M. scutellaris, native bee, typical of regions with climate and different altitude from the Brazilian northeast. In the state of Bahia it is found in altitudes of 36 and 1200 meters. One of the purposes of this study was to evaluate the effect of the altitude in the genetic and morphological diversity of populations of M. scutellaris collected in different altitudes of regions of Atlantic Forest and Caatinga in the state of Bahia. This paper also had as a purpose to investigate whether the protein heterocromatin 1 (HP1) is expressed in the genus Melipona. The genetic diversity was estimated based on mitochondrial haplotypes obtained by PCR-RFLP of the region COI/COII of the mitochondrial DNA of 29 workers sampled in the municipalities of Camaçari, Mundo Novo and Morro do Chapéu. A haplotypical composition with 12 haplotypes was obtained. Exclusive haplotypes and high genetic organization were observed when the three populations were evaluated. The UPGMA dendrogram showed the division of the populations into two main groups. The dendrogram topology shows greater genetical differentiation among the population of Camaçari and the populations of Mundo Novo and Morro do Chapéu and a close genetic relationship among the populations of Mundo Novo and Morro do Chapéu. Complementary genetic data may be obtained by evaluation of populations of M.scutellaris not analyzed, which may allow a more precise genetic characterization of this group of bees. Using scanning electronic microscopy, antennal sensillas of the type trichoid were evaluated in the three most distal ( F8, F9 e F10) flagellomers (F) of antennas of M. Scutellaris sampled in the locations with altitudes of 200 m (Group 1) and above 900 m (Group 2). Sensillas of curved end and of straight edge were observed in both groups; however, the sensillas of straight edge were detected in higher number in the bees collected at 200 m and of curved end in the bees of more elevated altitude (above 900m). The comparison of the number of sensillas of straight edge among the flagellomers of the bees from both groups resulted in significant difference for the three flagellomers. However, for the sensilla of curved end, the difference was significant only when the sensillas of flagellomer F9 were compared. These results may contribute in the future for the understanding of the relationships between M. scutellaris and the environment regarding altitude. One of the characteristics of the genus Melipona is the variation in the content of hetrocromatin (high and low content) among the species. In order to investigate a possible relationship between the protein Heterocromatin 1 (HP1) and the content of heterocromatin of this genus, two species of Melipona, M. mondury (high content) and M. quadrifasciata (low content) were evaluated based on the assay of immunolocalization and Western Blotting analysis. The obtained result showed that protein HP1 is expressed in both analyzed species. The presence of three immunolocalization stains for HP1 for each species suggests the detection of possible isoforms of HP1. The most intense stain of one of the possible isoforms of M. mondury suggests a greater expression of the protein in this species. Contrary to M. quadrifasciata, M. mondury has high content of heterocromatin and further analyses may contribute in the future to verify whether there is a relationship with the most expressed isoform (most intense stain) and the content of heterocromatin of M. mondury.