Search results for "ogas"

Evolution of gypsy Endogenous Retrovirus in the Drosophila obscura Species Group

2000

The Ty3/gypsy family of retroelements is closely related to retroviruses, and some of their members have an open reading frame resembling the retroviral gene env. Sequences homologous to the gypsy element from Drosophila melanogaster are widely distributed among Drosophila species. In this work, we report a phylogenetic study based mainly on the analysis of the 5' region of the env gene from several species of the obscura group, and also from sequences already reported of D. melanogaster, Drosophila virilis, and Drosophila hydei. Our results indicate that the gypsy elements from species of the obscura group constitute a monophyletic group which has strongly diverged from the prototypic D. m…

Ty3/Gypsy Retrotransposons: Description of New Arabidopsis thaliana Elements and Evolutionary Perspectives Derived from Comparative Genomic Data

2000

We performed a comprehensive analysis of the evolution of the Ty3/GYPSY: group of long-terminal-repeat retrotransposons (also known as METAVIRIDAE:). Exhaustive database searches allowed us to detect novel elements of this group. In particular, the Arabidopsis thaliana and Drosophila melanogaster genome sequencing projects have recently disclosed a large number of new Ty3/GYPSY: sequences. So far, elements of three different Ty3/GYPSY: lineages had been described for A. thaliana. Here, we describe six new lineages, which we have called Tit-for-tat1, Tit-for-tat2, Gimli, Gloin, Legolas, and Little Athila. We confirm that plant Ty3/GYPSY: elements form two main monophyletic groups. Moreover, …

Genetic and Cytological Analysis of Drosophila Chromatin-Remodeling Factors

2003

Tirant: A new retrotransposon-like element inDrosophila melanogaster

1996

In this paper we report a new retrotransposon-like element of Drosophila melanogaster called Tirant. This sequence is moderately repeated in the genome of this species and it has been found to be widely dispersed throughout its distribution area. From Southern blot and in situ analyses, this sequence appears to be mobile in D. melanogaster, since its chromosome location and the hybridization patterns vary among the different strains analyzed. In this way, partial sequencing of Tirant ends suggests that it is a retrotransposon, since it is flanked by two LTRs. The presence of sequences homologous to Tirant has been also investigated in 28 species of the genus Drosophila by means of Southern …

Spider odors induce stoichiometric changes in fruit fly Drosophila melanogaster

2020

Sequences homologous to the hobo transposable element in E strains of Drosophila melanogaster.

2001

Hobo is one of the three Drosophila melanogaster transposable elements, together with the P and I elements, that seem to have recently invaded the genome of this species. Surveys of the presence of hobo in strains from different geographical and temporal origins have shown that recently collected strains contain complete and deleted elements with high sequence similarity (H strains), but old strains lack hobo elements (E strains). Besides the canonical hobo sequences, both H and E strains show other poorly known hobo-related sequences. In the present work, we analyze the presence, cytogenetic location, and structure of some of these sequences in E strains of D. melanogaster. By in situ hybr…

Spatial discontinuity of Optomotor-blind expression in the Drosophila wing imaginal disc disrupts epithelial architecture and promotes cell sorting

2010

Abstract Background Decapentaplegic (Dpp) is one of the best characterized morphogens, required for dorso-ventral patterning of the Drosophila embryo and for anterior-posterior (A/P) patterning of the wing imaginal disc. In the larval wing pouch, the Dpp target gene optomotor-blind (omb) is generally assumed to be expressed in a step function above a certain threshold of Dpp signaling activity. Results We show that the transcription factor Omb forms, in fact, a symmetrical gradient on both sides of the A/P compartment boundary. Disruptions of the Omb gradient lead to a re-organization of the epithelial cytoskeleton and to a retraction of cells toward the basal membrane suggesting that the O…

Arthropod 7SK RNA

2008

The 7SK small nuclear RNA (snRNA) is a key player in the regulation of polymerase (pol) II transcription. The 7SK RNA was long believed to be specific to vertebrates where it is highly conserved. Homologs in basal deuterostomes and a few lophotrochozoan species were only recently reported. On longer timescales, 7SK evolves rapidly with only few conserved sequence and structure motifs. Previous attempts to identify the Drosophila homolog thus have remained unsuccessful despite considerable efforts. Here we report on the discovery of arthropod 7SK RNAs using a novel search strategy based on pol III promoters, as well as the subsequent verification of its expression. Our results demonstrate th…

Sequence, molecular organization and products of the Drosophila virilis homologs of the D. melanogaster nested genes lethal(2)tumorous imaginal discs…

1997

Abstract In this study, we describe the isolation of the Drosophila virilis (Dvir) 6201-bp genomic fragment homologous to a 7047-bp genomic region of D. melanogaster (Dmel) that harbors the nested genes lethal(2)tumorous imaginal discs (l(2)tid), lethal(2)neighbour of tid (l(2)not) and lethal(2)relative of tid (l(2)rot). The isolated fragment, which maps at the cytogenetic position 50A5 on chromosome 5, carries the Dvir homologs of the Dmel genes l(2)tid and l(2)not. In both cases, the interspecific comparison of the determined sequences reveals a high homology regarding the protein coding regions and a high degree of evolutionary divergence concerning the intronic parts of the genes. In th…

Identification of 5,6,7,8-tetrahydropterin and 5,6,7,8-tetrahydrobiopterin in Drosophila melanogaster.

1988

Summary Using reversed-phase high-performance liquid chromatography with electrochemical detection we have demonstrated the occurrence of 5,6,7,8-tetrahydropterin and 5,6,7,8-tetrahydrobiopterin in Drosophila melanogaster . The former is the first time that has been detected in vivo . The identification has been based on the retention times, hydrodinamic voltagrams and the differential concentration in three strains of Drosophila melanogaster . Compared to the wild type, the Punch 2 mutant has diminished levels of both pteridines, whereas Henna-recessive 3 lacks completely tetrahydropterin and has increased levels of tetrahydrobiopterin, as expected according to their biochemical lesions.