scholarly journals The development of the bristles in normal and some mutant types of Drosophila melanogaster

1942 ◽  
Vol 131 (862) ◽  
pp. 87-110 ◽  
Keyword(s):  
Drosophila Melanogaster ◽  
Single Cell ◽  
Epidermal Cells ◽  
After Puparium Formation ◽  
Puparium Formation ◽  
Tormogen Cell

This paper describes the development of the normal macro- and micro-chaetae of Drosophila , together with that of twelve mutant types. The phenotypes of twenty combinations of these genes have been studied. Each normal bristle is secreted by a single cell, the trichogen, which lies beneath a tormogen cell which secretes a socket. These bristle cells are first distinguishable in the epidermis at about 15 hr. after puparium formation, when they have already divided to form a pair, and are slightly larger than the normal epidermal cells. The secretion of the bristle proceeds most rapidly between 30 and 55 hr., during which time the bristle cells are very large and obviously highly polyploid. The socket, apparently, does not completely enclose the base of the bristle in the earliest stages. The development of the microchaetae is essentially similar to that of the macrochaetae. The actions of the twelve genes can be summarized as follows: Scute causes a primary absence of certain bristle cells, and extra-bristle-complex -41 e and hairy the presence of supernumerary groups. Split frequently causes an extra division, so that a group of four cells is formed; these may be arranged as two trichogens and two tormogens, or one trichogen and three tormogens; or the whole group may fail to reach the surface of the epithelium, when no bristle or socket is formed. Dichaete may produce an effect similar to the last-described of split , and it may also cause an extra division of the trichogen, producing a double bristle in a single socket. Hairless causes the trichogens of some bristle groups to lie level with the tormogens, and to develop like them into sockets. In Stubble the tormogens are shifted rather to one side of the trichogens, so that the bristle is less closely invested by the socket, and becomes thicker and shorter. In shaven-naked the trichogen is irregularly displaced, becoming more or less converted into a tormogen; the small bristle which may be secreted is often peculiarly fanned out at the tip, suggesting an effect of the gene on the nature of the material secreted. Spineless and morula slow down the growth of the bristle cells. Singed, forked and Bristle all affect the nature of the bristle secretion, there being some reason to suggest that the effects of Bristle and singed may be similar and different to that of forked.

Development of the Drosophila mushroom bodies: sequential generation of three distinct types of neurons from a neuroblast

Development ◽  
1999 ◽  
Vol 126 (18) ◽  
pp. 4065-4076 ◽  
Author(s):  
T. Lee ◽  
A. Lee ◽  
L. Luo
Keyword(s):  
Single Cell ◽  
Larval Stage ◽  
Mushroom Body ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Mushroom Bodies ◽  
After Puparium Formation ◽  
Body Development ◽  
Drosophila Brain ◽  
Puparium Formation

The mushroom bodies (MBs) are prominent structures in the Drosophila brain that are essential for olfactory learning and memory. Characterization of the development and projection patterns of individual MB neurons will be important for elucidating their functions. Using mosaic analysis with a repressible cell marker (Lee, T. and Luo, L. (1999) Neuron 22, 451–461), we have positively marked the axons and dendrites of multicellular and single-cell mushroom body clones at specific developmental stages. Systematic clonal analysis demonstrates that a single mushroom body neuroblast sequentially generates at least three types of morphologically distinct neurons. Neurons projecting into the (gamma) lobe of the adult MB are born first, prior to the mid-3rd instar larval stage. Neurons projecting into the alpha' and beta' lobes are born between the mid-3rd instar larval stage and puparium formation. Finally, neurons projecting into the alpha and beta lobes are born after puparium formation. Visualization of individual MB neurons has also revealed how different neurons acquire their characteristic axon projections. During the larval stage, axons of all MB neurons bifurcate into both the dorsal and medial lobes. Shortly after puparium formation, larval MB neurons are selectively pruned according to birthdays. Degeneration of axon branches makes early-born gamma neurons retain only their main processes in the peduncle, which then project into the adult gamma lobe without bifurcation. In contrast, the basic axon projections of the later-born (alpha'/beta') larval neurons are preserved during metamorphosis. This study illustrates the cellular organization of mushroom bodies and the development of different MB neurons at the single cell level. It allows for future studies on the molecular mechanisms of mushroom body development.

Development of adult sensilla on the wing and notum of Drosophila melanogaster

Development ◽  
1989 ◽  
Vol 107 (2) ◽  
pp. 389-405 ◽  
Author(s):  
V. Hartenstein ◽  
J.W. Posakony
Keyword(s):  
Cell Lineage ◽  
Precursor Cell ◽  
Random Pattern ◽  
Wing Margin ◽  
After Puparium Formation ◽  
First Order ◽  
Accessory Cells ◽  
Puparium Formation ◽  
Tormogen Cell ◽  
Adult Drosophila

We have investigated the temporal pattern of appearance, cell lineage, and cytodifferentiation of selected sensory organs (sensilla) of adult Drosophila. This analysis was facilitated by the discovery that the monoclonal antibody 22C10 labels not only the neuron of the developing sensillum organ, but the accessory cells as well. The precursors of the macrochaetes and the recurved (chemosensory) bristles of the wing margin divide around and shortly after puparium formation, while those of the microchaetes and the stout and slender (mechanosensory) bristles of the wing margin divide between 9 h and 18 h after puparium formation (apf). The onset of sensillum differentiation follows the terminal precursor division within a few hours. Four of the cells in an individual microchaete organ are clonally related: A single first-order precursor cell divides to produce two second-order precursors; one of these divides into the neuron and thecogen cell, the other into the trichogen cell and tormogen cell. Along the anterior wing margin, two rounds of division generate the cells of the mechanosensory sensilla; here, no strict clonal relationship seems to exist between the cells of an individual sensillum. At the time of sensillum precursor division, many other, non-sensillum-producing cells within the notum and wing proliferate as well. This mitotic activity follows a spatially non-random pattern.

A new approach reveals syncytia within the visceral musculature ofDrosophila melanogaster

Development ◽  
2001 ◽  
Vol 128 (13) ◽  
pp. 2517-2524 ◽  
Author(s):  
Robert Klapper ◽  
Sandra Heuser ◽  
Thomas Strasser ◽  
Wilfried Janning
Keyword(s):  
Drosophila Melanogaster ◽  
Single Cell ◽  
Cell Transplantation ◽  
Reporter Gene ◽  
Mononuclear Cells ◽  
Single Cells ◽  
New Approach ◽  
Transplantation Technique ◽  
Somatic Musculature ◽  
Somatic Muscles

In order to reveal syncytia within the visceral musculature of Drosophila melanogaster, we have combined the GAL4/UAS system with the single-cell transplantation technique. After transplantation of single cells from UAS-GFP donor embryos into ubiquitously GAL4-expressing recipients, the expression of the reporter gene was exclusively activated in syncytia containing both donor- and recipient-derived nuclei. In the first trial, we tested the system in the larval somatic musculature, which is already known to consist of syncytia. By this means we could show that most of the larval somatic muscles are generated by clonally non-related cells. Moreover, using this approach we were able to detect syncytia within the visceral musculature – a tissue that has previously been described as consisting of mononuclear cells. Both the longitudinal visceral musculature of the midgut and the circular musculature of the hindgut consist of syncytia and persist through metamorphosis. This novel application of the transplantation technique might be a powerful tool to trace syncytia in any organism using the GAL4/UAS system.

The spatial organization of epidermal structures: hairy establishes the geometrical pattern of Drosophila leg bristles by delimiting the domains of achaete expression

Development ◽  
1993 ◽  
Vol 118 (1) ◽  
pp. 9-20 ◽  
Author(s):  
T.V. Orenic ◽  
L.I. Held ◽  
S.W. Paddock ◽  
S.B. Carroll
Keyword(s):  
Drosophila Melanogaster ◽  
Spatial Organization ◽  
Expression Patterns ◽  
Cell Types ◽  
Precursor Cells ◽  
Geometrical Pattern ◽  
Leg Development ◽  
Puparium Formation ◽  
Late Expression ◽  
Bristle Pattern

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.

A single cell approach to problems of cell lineage and commitment during embryogenesis of Drosophila melanogaster

Development ◽  
1987 ◽  
Vol 100 (1) ◽  
pp. 1-12 ◽  
Author(s):  
G.M. Technau
Keyword(s):  
Drosophila Melanogaster ◽  
Single Cell ◽  
Cell Lineage ◽  
Cellular Level ◽  
Central Importance ◽  
Cell Level ◽  
Combined Application ◽  
A Cell ◽  
Pole Cells ◽  
Drosophila Embryos

The mechanisms leading to the commitment of a cell to a particular fate or to restrictions in its developmental potencies represent a problem of central importance in developmental biology. Both at the genetic and at the molecular level, studies addressing this topic using the fruitfly Drosophila melanogaster have advanced substantially, whereas, at the cellular level, experimental techniques have been most successfully applied to organisms composed of relatively large and accessible cells. The combined application of the different approaches to one system should improve our understanding of the process of commitment as a whole. Recently, a method has been devised to study cell lineage in Drosophila embryos at the single cell level. This method has been used to analyse the lineages, as well as the state of commitment of single cell progenitors from various ectodermal, mesodermal and endodermal anlagen and of the pole cells. The results obtained from a clonal analysis of wild-type larval structures are discussed in this review.

scholarly journals Single Cell and Open Chromatin Analysis Reveals Molecular Origin of Epidermal Cells of the Skin

2018 ◽  
Vol 47 (1) ◽  
pp. 21-37.e5 ◽  
Author(s):  
Xiying Fan ◽  
Dongmei Wang ◽  
Jeremy Evan Burgmaier ◽  
Yudong Teng ◽  
Rose-Anne Romano ◽  
...  
Keyword(s):  
Single Cell ◽  
Epidermal Cells ◽  
Open Chromatin ◽  
Molecular Origin

scholarly journals ELECTRON MICROSCOPIC STUDIES ON THE INDIRECT FLIGHT MUSCLES OF DROSOPHILA MELANOGASTER

1963 ◽  
Vol 17 (2) ◽  
pp. 351-362 ◽  
Author(s):  
S. Ahmad Shafiq
Keyword(s):  
Drosophila Melanogaster ◽  
Epidermal Cells ◽  
Uniform Density ◽  
Electron Microscopic ◽  
Thick Filaments ◽  
Irregular Pattern ◽  
Regular Arrangement ◽  
Microscopic Studies ◽  
Hexagonal Arrangement ◽  
Flight Muscles

The myofibrils in Drosophila have thick and thin types of myofilaments arranged in the hexagonal pattern described for Calliphora by Huxley and Hanson (15). The thick filaments, along most of their length in the A band, seem to be binary in structure, consisting of a dense cortex and a lighter medulla. In the H zone, however, they show more uniform density; lateral projections (bridges) also appear to be absent in this region. The M band has a varying number of granules (probably of glycogen) distributed between the myofilaments. The myofilaments on reaching the Z region appear to change their hexagonal arrangement and become connected to one another by Z filaments. The regular arrangement of the filaments found in most regions of the fibrils is not seen in the terminal sarcomeres of some flight muscles; the two types of filaments appear to be intermingled in an irregular pattern in these parts of the fibrils. The attachment of myofibrils to the cuticle through the epidermal cells is described.

scholarly journals Differential Gene Expression in Individual Papilla-Resistant and Powdery Mildew-Infected Barley Epidermal Cells

2004 ◽  
Vol 17 (7) ◽  
pp. 729-738 ◽  
Author(s):  
Torben Gjetting ◽  
Timothy L. W. Carver ◽  
Leif Skøt ◽  
Michael F. Lyngkjær
Keyword(s):  
Gene Expression ◽  
Powdery Mildew ◽  
Single Cell ◽  
Pcr Amplification ◽  
Epidermal Cells ◽  
Powdery Mildew Fungus ◽  
Pathogenesis Related Protein ◽  
Infected Cells ◽  
Transcript Profiles ◽  
Microarray Expression

Resistance and susceptibility in barley to the powdery mildew fungus (Blumeria graminis f. sp. hordei) is determined at the single-cell level. Even in genetically compatible interactions, attacked plant epidermal cells defend themselves against attempted fungal penetration by localized responses leading to papilla deposition and reinforcement of their cell wall. This conveys a race-nonspecific form of resistance. However, this defense is not complete, and a proportion of penetration attempts succeed in infection. The resultant mixture of infected and uninfected leaf cells makes it impossible to relate powdery mildew-induced gene expression in whole leaves or even dissected epidermal tissues to resistance or susceptibility. A method for generating transcript profiles from individual barley epidermal cells was established and proven useful for analyzing resistant and successfully infected cells separately. Contents of single epidermal cells (resistant, infected, and unattacked controls) were collected, and after cDNA synthesis and PCR amplification, the resulting sample was hybridized to dot-blots spotted with genes, including some previously reported to be induced upon pathogen attack. Transcripts of several genes, (e.g., PR1a, encoding a pathogenesis related protein, and GLP4, encoding a germin-like protein) accumulated specifically in resistant cells, while GRP94, encoding a molecular chaperone, accumulated in infected cells. Thus, the single-cell method allows discrimination of transcript profiles from resistant and infected cells. The method will be useful for microarray expression profiling for simultaneous analysis of many genes.

Oxidative Metabolism and Puparium Formation in the Ebony Mutant of Drosophila melanogaster

Nature ◽  
1959 ◽  
Vol 183 (4668) ◽  
pp. 1129-1130 ◽  
Author(s):  
ALEXANDER WOLSKY ◽  
HENRIETTA G. KALICKI
Keyword(s):  
Drosophila Melanogaster ◽  
Oxidative Metabolism ◽  
Puparium Formation
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