Search results for "melanogaster"
showing 10 items of 452 documents
Gypsy homologous sequences in Drosophila subobscura (gypsyDS).
1993
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…
Origin of neuronal-like receptors in Metazoa: cloning of a metabotropic glutamate/GABA-like receptor from the marine sponge Geodia cydonium.
1999
To date, no conclusive evidence has been presented for the existence of neuronal-like elements in Porifera (sponges). In the present study, isolated cells from the marine sponge Geodia cydonium are shown to react to the excitatory amino acid glutamate with an increase in the concentration of intracellular calcium [Ca2+]i. This effect can also be observed when the compounds L-quisqualic acid (L-QA) or L-(+)-2-amino-4-phosphonobutyric acid (L-AP-4) are used. The effect of L-QA and L-AP-4, both agonists for metabotropic glutamate receptors (mGluRs), can be abolished by the antagonist of group I mGluRs, (RS)-alpha-methyl-4-carboxyphenylglycine. These data suggest that sponge cells contain an mG…
The insect nephrocyte is a podocyte-like cell with a filtration slit diaphragm.
2008
The nephron is the basic structural and functional unit of the vertebrate kidney. It is composed of a glomerulus, the site of ultrafiltration, and a renal tubule, along which the filtrate is modified. Although widely regarded as a vertebrate adaptation, 'nephron-like' features can be found in the excretory systems of many invertebrates, raising the possibility that components of the vertebrate excretory system were inherited from their invertebrate ancestors. Here we show that the insect nephrocyte has remarkable anatomical, molecular and functional similarity to the glomerular podocyte, a cell in the vertebrate kidney that forms the main size-selective barrier as blood is ultrafiltered to …
On the analysis of viability data: an example with Drosophila.
1990
Larval competition experiments involving two wild type and eight mutant strains of Drosophila melanogaster have been carried out following the substitution procedure proposed by Mather and Caligari (1981). Our main goal has been to compare the competitive abilities of two phenotypically indistinguishable strains (wild and Oregon-R) by means of their responses with eight different mutants. Prior to the analyses of viability data, we have studied the normalizing effect of several transformations in order to determine which was best suited for the analyses. The differences found among the five transformations tested and the untransformed data were not very great. The folded power transformatio…
The Dorsocross T-box transcription factors promote tissue morphogenesis in the Drosophila wing imaginal disc.
2012
The Drosophila wing imaginal disc is subdivided into notum, hinge and blade territories during the third larval instar by formation of several deep apical folds. The molecular mechanisms of these subdivisions and the subsequent initiation of morphogenic processes during metamorphosis are poorly understood. Here, we demonstrate that the Dorsocross (Doc) T-box genes promote the progression of epithelial folds that not only separate the hinge and blade regions of the wing disc but also contribute to metamorphic development by changing cell shapes and bending the wing disc. We found that Doc expression was restricted by two inhibitors, Vestigial and Homothorax, leading to two narrow Doc stripes…
A comparison of the transcriptome of Drosophila melanogaster in response to entomopathogenic fungus, ionizing radiation, starvation and cold shock
2015
Background The molecular mechanisms that determine the organism's response to a variety of doses and modalities of stress factors are not well understood. Results We studied effects of ionizing radiation (144, 360 and 864 Gy), entomopathogenic fungus (10 and 100 CFU), starvation (16 h), and cold shock (+4, 0 and -4°C) on an organism's viability indicators (survival and locomotor activity) and transcriptome changes in the Drosophila melanogaster model. All stress factors but cold shock resulted in a decrease of lifespan proportional to the dose of treatment. However, stress-factors affected locomotor activity without correlation with lifespan. Our data revealed both significant similarities …
Effect of conditioned media on three genotypes ofDrosophila melanogaster: Physical, chemical, and biological aspects
1986
The uric acid contents in larvae, pupae, and culture media were studied during larval and pupal development in three genotypes of Drosophila melanogaster reared in both crowded and noncrowded conditions. The uric acid content and the response of genotypes in media supplemented with 10 and 15 mg/ml of uric acid were correlated with the outcome obtained in conditioned media. In addition, the behavior of genotypes in conditioned media is explained in terms of the physicochemical properties of the conditioned media, which include uric acid content, the amount of food ingested, the degree of free water, the physical disturbance within the cultures, and the particular response of each genotype to…
Larva-to-adult and pupa-to-adult mortality dynamics in crowded cultures ofDrosophila melanogaster
1985
Pupal mortality is shown here to bear the main responsibility for total mortality duringDrosophila melanogaster development in crowded conditions. The dynamics of the pupa-to-adult and larva-to-adult processes of mortality follows a S-shaped logistic model, like survival in density-dependent processes. Data given here confirm to some extent Wallace's suggestion that pupal mortality is a density-dependent process.
Larval competition in Drosophila melanogaster: frequency-dependence of viability
1988
The application of the overfeeding technique (interruption of the competition during larval development) to the study of larval competition in two-strain cultures of Drosophila melanogaster demonstrates the following points: (1) viability is a function of competition time; (2) viability becomes more frequency-dependent as competition time increases; (3) the dynamics of the “inner” subpopulation (adults that have passed all their development in a crowded condition) and “outer” subpopulation (adults coming from larvae recovered by interruption of competition) vary with time as regards frequency-dependence; and (4) the wild type strain Oregon is the active agent in competition with the strain …