Dynamics of the spatial organization of the chromosome set in cells of Drosophila melanogaster imaginal disks normally and under the action of the tumor-inducing mutation Merlin

2010 ◽  
Vol 46 (2) ◽  
pp. 157-163 ◽  
Author(s):  
L. I. Lebedeva ◽  
E. M. Akhmametyeva ◽  
L. V. Omelyanchuk
2018 ◽  
Vol 46 (11) ◽  
pp. 5561-5586 ◽  
Author(s):  
Roopali Pradhan ◽  
Devika Ranade ◽  
Kundan Sengupta

Development ◽  
1993 ◽  
Vol 118 (1) ◽  
pp. 9-20 ◽  
Author(s):  
T.V. Orenic ◽  
L.I. Held ◽  
S.W. Paddock ◽  
S.B. Carroll

The spatial organization of Drosophila melanogaster epidermal structures in embryos and adults constitutes a classic model system for understanding how the two dimensional arrangement of particular cell types is generated. For example, the legs of the Drosophila melanogaster adult are covered with bristles, which in most segments are arranged in longitudinal rows. Here we elucidate the key roles of two regulatory genes, hairy and achaete, in setting up this periodic bristle pattern. We show that achaete is expressed during pupal leg development in a dynamic pattern which changes, by approximately 6 hours after puparium formation, into narrow longitudinal stripes of 3–4 cells in width, each of which represents a field of cells (proneural field) from which bristle precursor cells are selected. This pattern of gene expression foreshadows the adult bristle pattern and is established in part through the function of the hairy gene, which also functions in patterning other adult sense organs. In pupal legs, hairy is expressed in four longitudinal stripes, located between every other pair of achaete stripes. We show that in the absence of hairy function achaete expression expands into the interstripe regions that normally express hairy, fusing the two achaete stripes and resulting in extra-wide stripes of achaete expression. This misexpression of achaete, in turn, alters the fields of potential bristle precursor cells which leads to the misalignment of bristle rows in the adult. This function of hairy in patterning achaete expression is distinct from that in the wing in which hairy suppresses late expression of achaete but has no effect on the initial patterning of achaete expression. Thus, the leg bristle pattern is apparently regulated at two levels: a global regulation of the hairy and achaete expression patterns which partitions the leg epidermis into striped zones (this study) and a local regulation (inferred from other studies on the selection of neural precursor cells) that involves refinement steps which may control the alignment and spacing of bristle cells within these zones.


Development ◽  
1988 ◽  
Vol 104 (Supplement) ◽  
pp. 85-93 ◽  
Author(s):  
Stephen J. Poole ◽  
Thomas B. Kornberg

The engrailed gene is required for segmentation of the Drosophila embryo and is expressed in cells constituting the posterior developmental compartments. In mutant embryos lacking engrailed function, portions of the cuticular pattern in each segment are deleted, resulting in fusion of adjacent denticle bands. Using P-element-mediated transposition, we generated flies that express the engrailed gene under the control of an hsp70 promoter, and found that ectopic, heat-shock-induced, engrailed expression caused pattern defects similar to those in embryos lacking engrailed function. Sensitivity to heat shock was only during the cellular blastoderm and early gastrulation periods. This window of sensitivity corresponds to the time when wildtype engrailed protein localizes into segmentally reiterated stripes and represents only a small portion of the normal period of engrailed gene expression.


1976 ◽  
Vol 29 (4) ◽  
pp. 375 ◽  
Author(s):  
JA Sved

Male.recombination and female sterility, two aspects of hybrid dysgenesis in D. melanogaster, have been studied in crosses between a locally collected wild population and laboratory strains. Dysgenesis occurs in the Fl hybrid of such crosses only if the wild type is used as maie parent and the laboratory strain as female, suggesting an interaction between genotype and cytoplasm. However the results from further crosses are difficult to interpret in terms of a conventional genotype--cytoplasm model, and suggest that for dysgenesis to occur it is necessary-that the wild-type chromosomes be contributed by the male parent. Furthermore, receipt of any of the three major wild-type chromosomes in crosses to laboratory females is sufficient to cause hybrid dysgenesis.


1997 ◽  
Vol 200 (14) ◽  
pp. 2007-2015 ◽  
Author(s):  
R A Krebs ◽  
M E Feder

All tissues of larval Drosophila melanogaster express Hsp70, the major heat-shock protein of this species, after both mild (36 degrees C) and severe (38.5 degrees C) heat shock. We used Hsp70-specific immunofluorescence to compare the rate and intensity of Hsp70 expression in various tissues after these two heat-shock treatments, and to compare this with related differences in the intensity of Trypan Blue staining shown by the tissues. Trypan Blue is a marker of tissue damage. Hsp70 was rarely detectable before heat shock. Brain, salivary glands, imaginal disks and hindgut expressed Hsp70 within the first hour of heat shock, whereas gut tissues, fat body and Malpighian tubules did not express Hsp70 until 4-21 h after heat shock. Differences in Hsp70 expression between tissues were more pronounced at the higher heat-shock temperature. Tissues that expressed Hsp70 slowly stained most intensely with Trypan Blue. Gut stained especially intensely, which suggests that its sensitivity to heat shock may limit larval thermotolerance. These patterns further suggest that some cells respond primarily to damage caused by heat shock rather than to elevated temperature per se and/or that Hsp70 expression is itself damaged by heat and requires time for recovery in some tissues.


1993 ◽  
Vol 25 (5) ◽  
pp. 751-762 ◽  
Author(s):  
Maria Giovanna Riparbelli ◽  
Giuliano Callaini ◽  
Dallai Romano

1987 ◽  
Vol 104 (6) ◽  
pp. 1471-1483 ◽  
Author(s):  
M Hochstrasser ◽  
J W Sedat

In the preceding article we compared the general organization of polytene chromosomes in four different Drosophila melanogaster cell types. Here we describe experiments aimed at testing for a potential role of three-dimensional chromosome folding and positioning in modulating gene expression and examining specific chromosome interactions with different nuclear structures. By charting the configurations of salivary gland chromosomes as the cells undergo functional changes, it is shown that loci are not repositioned within the nucleus when the pattern of transcription changes. Heterologous loci show no evidence of specific physical interactions with one another in any of the cell types. However, a specific subset of chromosomal loci is attached to the nuclear envelope, and this subset is extremely similar in at least two tissues. In contrast, no specific interactions between any locus and the nucleolus are found, but the base of the X chromosome, containing the nucleolar organizer, is closely linked to this organelle. These results are used to evaluate models of gene regulation that involve the specific intranuclear positioning of gene sequences. Finally, data are presented on an unusual class of nuclear envelope structures, filled with large, electron-dense particles, that are usually associated with chromosomes.


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