0000000000392624
AUTHOR
Trinidad M. Alberola
Molecular Structure of a Gypsy Element of Drosophila Subobscura (Gypsyds) Constituting a Degenerate Form of Insect Retroviruses
We have determined the nucleotide sequence of a 7.5 kb full-size gypsy element from Drosophila subobscura strain H-271. Comparative analyses were carried out on the sequence and molecular structure of gypsy elements of D.subobscura (gypsyDs), D.melanogaster (gypsyDm) and D.virilis (gypsyDv). The three elements show a structure that maintains a common mechanism of expression. ORF1 and ORF2 show typical motifs of gag and pol genes respectively in the three gypsy elements and could encode functional proteins necessary for intracellular expansion. In the three ORF1 proteins an arginine-rich region was found which could constitute a RNA binding motif. The main differences among the gypsy element…
Lack of association between proliferative verrucous leukoplakia and human papillomavirus infection.
Purpose To analyze proliferative verrucous leukoplakia (PVL) for the presence of human papillomavirus (HPV) in different stages of the disease. Materials and Methods We studied 13 patients with PVL. In 10 patients (76.9%), a lesional biopsy was taken and frozen at −40°C. Four patients were instructed to mouth rinse with sterile sera. The biopsy and rinse samples were analyzed for HPV by PCR. Results We did not detect HPV infection in the PVL tissue or in the oral rinse of any of the 13 patients in any stage of the disease analyzed, neither in oral squamous cell carcinoma nor in the simple hyperkeratosis. Conclusion There was no association between PVL and HPV infection in our patients.
Insecticidal Activity of Strains of Bacillus thuringiensis on Larvae and Adults of Bactrocera oleae Gmelin (Dipt. Tephritidae)
The olive fly, Bactrocera oleae, is the key pest on olives in the Mediterranean area. The pest can destroy, in some cases, up to 70% of the olive production. Its control relies mainly on chemical treatments, sometimes applied by aircraft over vast areas, with their subsequent ecological and toxicological side effects. Bacillus thuringiensis is a spore-forming soil bacterium which produces a protein crystal toxic to some insects, including the orders of Lepidoptera, Diptera, and Coleoptera and other invertebrates. The aim of this study was to search for isolates toxic to B. oleae. Several hundred B. thuringiensis isolates were obtained from olive groves and olive presses in different areas o…
Distribution of gypsy sequences in Drosophila species of the obscura subgroup.
Eight Drosophila species of the obscura subgroup were screened for sequences homologous to the gypsy retrotransposon of D. melanogaster. Molecular characterization of gypsy sequences was first approached through digesting genomic DNAs from these obscura species with appropriate restriction enzymes and subjecting them to Southern blot analysis. The results of this analysis indicate that gypsy-homologous sequences are well conserved among species of the obscura subgroup. With the exception of D. guanche, all other species bear a 7 kb Xho I fragment that represents the complete element in D. melanogaster. Lower molecular weight fragments that could be deleted elements, are shared by different …
A new set of DNA macrochips for the yeast Saccharomyces cerevisiae: features and uses
The yeast Saccharomyces cerevisiae has been widely used for the implementation of DNA chip technologies. For this reason and due to the extensive use of this organism for basic and applied studies, yeast DNA chips are being used by many laboratories for expression or genomic analyses. While membrane arrays (macroarrays) offer several advantages, for many laboratories they are not affordable. Here we report that a cluster of four Spanish molecular-biology yeast laboratories, with relatively small budgets, have developed a complete set of probes for the genome of S. cerevisiae. These have been used to produce a new type of macroarray on a nylon surface. The macroarrays have been evaluated and…
Distribution, frequency and diversity of Bacillus thuringiensis in olive tree environments in Spain
Summary Bacillus thuringiensis was isolated from samples collected from olive tree related habitats (olive groves, olive storage facilities and oil mills) of different olive producing regions in Spain. This bacterium was found in a high percentage (92%) of samples. From 72 samples analysed, 2244 sporulating colonies were selected and observed under phase contrast microscopy. From these, 414 colonies (18%) were classified as B. thuringiensis based on the production of parasporal crystals. A great variability of spore, crystal size and morphology was observed. The results indicate that olive groves are as rich as soil olive mills and olive storage facilities regarding the B. thuringiensis pop…
Structural analysis of Drosophila subobscura gypsy elements (gypsyDs)
The study of gypsy elements in Drosophila subobscura (gypsyDs) indicated that they are transcriptionally active and mobile. From the comparative analysis of a complete gypsyDs element with the canonical gypsy sequence from D. melanogaster (gypsyDm) it can be deduced that while the whole structure is maintained, the gypsyDs ORF3 encodes a non-functional Env protein. The PCR amplification and sequencing of the ORF3 from different laboratory strains and H271 clones show that all gypsyDs sequences studied have frame-shifting mutations in this region. These results support that gypsyDs elements lack functional Env proteins and consequently they lack infective ability. In this way, it can be prop…
DNA chips for yeast biotechnology. The case of wine yeasts.
The yeast Saccharomyces cerevisiae is one of the most popular model organisms. It was the first eukaryote whose genome was sequenced. Since then many functional analysis projects have tried to find the function of many genes and to understand its metabolism in a holistic way. Apart from basic science this microorganism is of great interest in several biotechnology processes, such as winemaking. Only global studies of the cell as a whole can help us to understand many of the technical problems facing winemaking. DNA chip technology is one of the most promising tools for the analysis of cell physiology. Yeast has been the model organism for the development of this technique. Many of the studi…
Gypsy homologous sequences in Drosophila subobscura (gypsyDS).
Characterization of sequences homologous to the Drosophila melanogaster gypsy transposable element was carried out in Drosophila subobscura (gypsyDS). They were found to be widely distributed among natural populations of this species. From Southern blot and in situ analyses, these sequences appear to be mobile in this species. GypsyDS sequences are located in both euchromatic and heterochromatic regions. A complete gypsyDS sequence was isolated from a D. subobscura genomic library, and a 1.3-kb fragment which aligns with the ORF2 of the D. melanogaster gypsy element was sequenced. Comparisons of this sequence in three species (D. subobscura, D. melanogaster, and D. virilis) indicate that th…