Bristle
Mostrando 25-36 de 135 artigos, teses e dissertações.
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25. Hox gene control of segment-specific bristle patterns in Drosophila
Hox genes specify the different morphologies of segments along the anteroposterior axis of animals. How they control complex segment morphologies is not well understood. We have studied how the Hox gene Ultrabithorax (Ubx) controls specific differences between the bristle patterns of the second and third thoracic segments (T2 and T3) of Drosophila melanogast
Cold Spring Harbor Laboratory Press.
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26. The Isolation of Polygenic Factors Controlling Bristle Score in Drosophila Melanogaster. II. Distribution of Third Chromosome Bristle Effects within Chromosome Sections
In the present study an attempt has been made to characterize the genetic ``factors'' controlling quantitative characters, bristle numbers, in Drosophila melanogaster. A low sternopleural bristle multiple recessive marker third chromosome was used to analyze a high sternopleural third chromosome, in a high sternopleural bristle background. An attempt was mad
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27. Effects of Single P-Element Insertions on Bristle Number and Viability in Drosophila Melanogaster
Single P-element mutagenesis was used to construct 1094 lines with P[lArB] inserts on all three major chromosomes in an isogenic background previously free of P elements. The effects of insertions on bristle number and on viability were assessed by comparison to 392 control lines. The variance and effects of P-element inserts on bristle number and viability
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28. High Resolution Mapping of Genetic Factors Affecting Abdominal Bristle Number in Drosophila Melanogaster
Factors responsible for selection response for abdominal bristle number and correlated responses in sternopleural bristle number were mapped to the X and third chromosome of Drosophila melanogaster. Lines divergent for high and low abdominal bristle number were created by 25 generations of artificial selection from a large base population, with an intensity
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29. Conditional Polygenic Effects in the Sternopleural Bristle System of DROSOPHILA MELANOGASTER
The chromosomal architecture of genotype x environment interactions was investigated in lines of Drosophila melanogaster selected for increased or decreased sternopleural bristle number at 18°, 25° and 29°. In general, interactions were found to have a stabilizing effect upon the bristle phenotype, in the sense that the genotype x environment interaction
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30. Genetic Interactions between Naturally Occurring Alleles at Quantitative Trait Loci and Mutant Alleles at Candidate Loci Affecting Bristle Number in Drosophila Melanogaster
Previously, we mapped quantitative trait loci (QTL) affecting response to short-term selection for abdominal bristle number to seven suggestive regions that contain loci involved in bristle development and/or that have adult bristle number mutant phenotypes, and are thus candidates for bristle number QTL in natural populations. To test the hypothesis that th
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31. Polygenic Mutation in Drosophila Melanogaster: Estimates from Response to Selection of Inbred Strains
Replicated divergent artificial selection for abdominal and sternopleural bristle number from a highly inbred strain of Drosophila melanogaster resulted in an average divergence after 125 generations of selection of 12.0 abdominal and 8.2 sternopleural bristles from the accumulation of new mutations affecting bristle number. Responses to selection were highl
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32. Effects of P Element Insertions on Quantitative Traits in Drosophila Melanogaster
P element mutagenesis was used to construct 94 third chromosome lines of Drosophila melanogaster which contained on average 3.1 stable P element inserts, in an inbred host strain background previously free of P elements. The homozygous and heterozygous effects of the inserts on viability and abdominal and sternopleural bristle number were ascertained by comp
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33. A Balance of Capping Protein and Profilin Functions Is Required to Regulate Actin Polymerization in Drosophila Bristle
Profilin is a well-characterized protein known to be important for regulating actin filament assembly. Relatively few studies have addressed how profilin interacts with other actin-binding proteins in vivo to regulate assembly of complex actin structures. To investigate the function of profilin in the context of a differentiating cell, we have studied an ins
The American Society for Cell Biology.
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34. The Role Actin Filaments Play in Providing the Characteristic Curved Form of Drosophila BristlesD⃞
Drosophila bristles display a precise orientation and curvature. An asymmetric extension of the socket cell overlies the newly emerging bristle rudiment to provide direction for bristle elongation, a process thought to be orchestrated by the nerve dendrite lying between these cells. Scanning electron microscopic analysis of individual bristles showed that cu
The American Society for Cell Biology.
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35. Genetic and Molecular Analysis of Smooth, a Quantitative Trait Locus Affecting Bristle Number in Drosophila Melanogaster
A semi-lethal, sterile allele of the smooth locus (2-91.5), sm(3), was discovered in an artificial selection line for low abdominal bristle number that had been started from a P-M dysgenic cross. The fitness effects and extremely low bristle number phenotype of the allele could not be separated by recombination from a P-element insertion at cytological locat
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36. Is There a Gene Regulating the Scute Locus on the Third Chromosome of D. MELANOGASTER?
A section of the third chromosome of D. melanogaster some 25 to 40 centimorgans long including sr was transferred from a wild-type stock selected by Latter for high scutellar bristle number into a scute stock with a large number of scutellar bristles. This segment is shown to have a large effect on the bristle numbers of wild-type flies, to reduce the streng