Browsing by Author "Montiel, Rafael"
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- Morphometry of the epidermis of an invasive megascoelecid earthworm (Amynthas gracilis, Kinberg 1867) inhabiting actively volcanic soils in the Azores archipelagoPublication . Cunha, Luís; Campos, Itxaso; Montiel, Rafael; Rodrigues, Armindo; Morgan, AndrewFor the first time, the structure, dimensions, and composition of the epidermis of an invasive earthworm species that has successfully colonized hostile conditions in actively volcanic soil on Sao Miguel (Azores) have been measured. Metal concentrations in actively volcanic (Furnas) and volcanically inactive(Fajã) soils were similar; however, Furnas soil was characterised by elevated temperature (10 1C differential), relative hypoxia, extremely high CO2 tension, and accompanying acidity. The epidermis of earthworm’s resident at Fajã was approximately twice the thickness of the epidermis of conspecifics resident in Furnas soil. Reference worms transferred to Furnas soil for 14 days experienced an epidermal thinning of approximately 51%. In comparison, when Furnas earthworms were transferred to mesocosms at the relatively benign Fajã site, their epidermal thickness increased by approximately 21%over 14 days. Earthworms resident in Furnas soil had higher goblet cell counts than the residents of volcanically inactive soil on a neighbouring island (S.Maria). Transferring worms from S.Maria to mesocosmsat Furnas induced a significant increase in goblet cell counts. Clearly, the active volcanic environment at Furnas poses a multifactorial stress challenge to the epigeic A. gracilis colonizer.
- Occurrence and characterization of a nucleopolyhedrovirus from Spodoptera littoralis (Lepidoptera: Noctuidae) isolated in the AzoresPublication . Martins, Tiago; Montiel, Rafael; Medeiros, Jorge; Oliveira, Luísa; Simões, NelsonA nucleopolyhedrovirus (SpliMNPV-Az) was isolated from diseased larvae of Spodoptera littoralis, collected at the Island of S. Miguel in Azores. The virulence of this isolate was tested against S. littoralis larvae in laboratory. LD50 against 2nd and 3rd instars were not significantly different larvae, but both were significantly different from that against 4th instar. The complete codons sequence of SpliMNPV-Az Polh gene obtained was 750 bp (NCBI GenBank Accession No. AY600451). This sequence was compared to other 38 polyhedrin genes from NPVs and to 6 granulin genes from GVs and resulted to be identical to the sequence of a SpliMNPV previously published, thus indicating that the natural host of SpliMNPV-Az must be S. littoralis. Genetic distances estimated from restriction enzymes profiles showed SpliMNPV-Az is close to the Egyptian SpliMNPV type B, despite some degree of genetic divergence suggested by slight differences observed on PstI profile.
- Polymorphism of the APOE locus in the Azores Islands (Portugal)Publication . Bettencourt, Conceição; Montiel, Rafael; Santos, Cristina; Pavão, Maria Leonor; Viegas-Crespo, Ana Maria; Lopes, Paula Alexandra; Lima, ManuelaOur aim in this study is to report on the polymorphism of the APOE gene in the Azores Islands (Portugal) to obtain a population baseline of the existing variation in this locus, known to be one of the genetic determinants of plasma lipid levels. One hundred twenty-six Azorean individuals were typed for the APOE polymorphism using standard PCR-RFLP. Allele frequencies obtained for APOE*2, APOE*3, and APOE*4 were 6.75%, 83.73%, and 9.52%, respectively. The APOE*3/*3 genotype presented the highest frequency (69.84%), and the APOE*4/*4 genotype had the lowest frequency (0.79%). Genotype frequencies were in conformity with Hardy-Weinberg expectations. The observed genotype and allele frequencies were similar to those reported for other Iberian samples. Furthermore, Nei's gene diversity ((H) over cap = 0.2864 +/- 0.0351) was similar to that reported for samples from mainland Portugal. The data generated from this study will be of importance in the context of ongoing studies concerning the factors that influence lipid levels in the Azorean population.
- Polymorphism of the ApoE locus in the Azores Islands (Portugal)Publication . Bettencourt, Conceição; Montiel, Rafael; Santos, Cristina; Pavão, Maria Leonor; Viegas-Crespo, Ana Maria; Lopes, Paula Alexandra; Lima, ManuelaThe aim of this work was to report on the polymorphism of the ApoE locus in the Azores Islands (Portugal) in order to get insights on the genetic background that influences the lipid profile in this population, ascertained as considerably high in a preliminary study of a sample of healthy subjects (60% of individuals were hypercholesterolemics). One hundred and twenty six Azorean individuals were typed for ApoE polymorphism using standard PCR-RFLP. The allelic frequencies obtained for ε2, ε3 and ε4 were 6.75%, 83.73% and 9.52%, respectively. Genotypic frequencies were in conformity with Hardy-Weinberg expectations. The ε3/ε3 genotype presented the highest frequency (69.84%), whilst ε4/ε4 was the least frequent (0.79%). The genotypic and allelic frequencies observed were similar to those reported for other Iberian samples. Furthermore, Nei’s gene diversity (0.2864±0.0351) was similar to the reported for samples from Mainland Portugal. Results obtained did not evidence a particular behaviour of the ApoE locus that could be directly related with the high levels of total cholesterol determined in the Azorean population.
- Recolha de amostras de solo nas ilhas do Pico e Faial para isolamento de bactérias e nemátodes entomopatogénicosPublication . Montiel, Rafael; Nascimento, Gisela; Ferreira, RicardoDurante a Expedição Científica PICO 2005 recolheram-se oitenta e sete amostras de solo na Ilha do Pico e dezassete no Faial a diferentes altitudes e com diversos cobertos vegetais que foram transportadas para o laboratório de Entomopatologia para isolamento de bactérias e nemátodes entomopatogénicos. Todas as amostras já foram analisadas pelo método da Galleria trap para nemátodes não se tendo identificado nenhuma positiva. Para bactérias entomopatogénicas analisámos 55 amostras de onde obtivemos 108 isolados puros, 16 deles pertencentes ao Grupo I de Bacillus. Estes isolados estão neste momento a ser identificados a nível da espécie por métodos bioquímicos e moleculares. Todos os isolados estão depositados no BEA/CIRN.
- The speciation of Noctua atlantica (Lepidoptera, Noctuidae) occurred in the Azores as supported by a molecular clock based on mitochondrial COI sequencesPublication . Montiel, Rafael; Vieira, Virgílio; Martins, Tiago; Oliveira, LuísaThe complete sequence of the cytochrome c oxidase subunit I (COI) gene of Noctua atlantica (Warren, 1905) has been determined and deposited in the NCBI GenBank under the Accession number AY600452. Complete and partial COI sequences of other Lepidoptera have been collected and used to reconstruct a phylogeny with both the Neighbor-Joining and the Maximum Likelihood methods. A molecular clock calibrated for our models indicate a divergence time between Noctua atlantica and Noctua pronuba of 4.7-5.9 Million years, consistent with the geological age of the Azores and suggesting that the speciation process of N. atlantica occurred in this archipelago.