Search results for "Subgenus"

Flush-Crash Experiments in Drosophila

1989

In 1968, Hampton Carson (1968) proposed the founder-flush-crash model, a new model of speciation, which readily lends itself to experimental testing in the laboratory (Carson 1971).

Genetic analysis of heat shock response in three Drosophila species of the obscura group

1992

Heat shock response was investigated in three species of the obscura group of the Drosophila genus (D. subobscura, D. guanche, and D. madeirensis) by chromosome cytology analysis and [3H]uridine labeling. A set of eight puffs (2C, 15DE, 18C, 27A, 31CD, 85AB, 89A, and 94A) were induced after heat treatments in each of the three species; 18C, 27A, 89A, and 94A were the most heavily labeled in the autoradiograms after the induced conditions. From the in situ results using the major heat shock genes of D. melanogaster as a probe, it was inferred that the 18C, 94A, 89A, and 27A loci of the three obscura group species are homologous to D. melanogaster loci, which contain, HSP82, HSP70, HSP68, an…

P2‐077: Identification of potential modifiers of Alzheimer's disease pathology by quantitative mass spectrometry and drosophila genetics

2015

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…

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 …

Molecular evolution of P transposable elements in the Genus drosophila. II. The obscura species group.

1998

A phylogenetic analysis of P transposable elements in the Drosophila obscura species group is described. Multiple P sequences from each of 10 species were obtained using PCR primers that flank a conserved region of exon 2 of the transposase gene. In general, the P element phylogeny is congruent with the species phylogeny, indicating that the dominant mode of transmission has been vertical, from generation to generation. One manifestation of this is the distinction of P elements from the Old World obscura and subobscura subgroups from those of the New World affinis subgroup. However, the overall distribution of elements within the obscura species group is not congruent with the phylogenetic …

Phylogenetic relationships between Drosophila subobscura, D. guanche and D. madeirensis based on Southern analysis of heat shock genes.

2004

A Southern analysis of genomic DNA using Drosophila melanogaster probes for the major heat shock protein genes (Hsp82, Hsp 70, Hsps encoding small proteins) was made to study the phylogenetic relationships between three Drosophila species belonging to the obscura group (D. subobscura, D. guanche, and D. madeirensis). The phylogenetic trees showed that D. madeirensis and D. subobscura are the most closely related species in the triad, while D. guanche is the most distantly related one. As in other Drosophila species, Hsp82 is a single copy gene in D. subobscura, D. guanche, and D. madeirensis, while Hsp 70 and Hsps, which encode small proteins, are genie families. At least four sequences hom…

Distribution of gypsy sequences in Drosophila species of the obscura subgroup.

2004

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 …

Structural analysis of Drosophila subobscura gypsy elements (gypsyDs)

1997

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…