scholarly journals Nuclear antigens follow different pathways into daughter nuclei during mitosis in early Drosophila embryos

1986 ◽  
Vol 82 (1) ◽  
pp. 155-172
Author(s):  
M. Frasch ◽  
D.M. Glover ◽  
H. Saumweber
Keyword(s):  
Drosophila Melanogaster ◽  
Monoclonal Antibodies ◽  
Embryonic Development ◽  
Central Region ◽  
Immunofluorescence Microscopy ◽  
The Other ◽  
Indirect Immunofluorescence Microscopy ◽  
Nuclear Antigens ◽  
Late Telophase ◽  
Drosophila Embryos

In the early embryonic development of Drosophila melanogaster, there is a series of 13 rapid and highly synchronous nuclear divisions. We have used a collection of monoclonal antibodies to follow the re-distribution of nuclear antigens into daughter nuclei at this developmental stage by indirect immunofluorescence microscopy. The antigens fall into several categories in terms of the pathways that are followed at mitosis. At one extreme is a group of antigens that remains continuously associated with the DNA throughout all the mitotic phases. At the other extreme, another group of antigens is excluded from the nucleus at prophase, and does not associate with the nucleus again until late telophase. One antigen, which becomes incorporated into the nucleolus at cellularization after the thirteenth division, becomes associated with the chromosomes during mitosis, but not until anaphase. Several different antibodies stain a diamond-shaped compartment that develops over the spindle at anaphase. The distribution of antigens within this spindle compartment shows some variation: one antigen appears to be present at higher concentrations in the central region of the spindle; others appear in three quite distinct areas corresponding to the positions of the new daughter nuclei and the old parental nucleus. Yet another antibody gives uniform staining of the spindle compartment. This antibody also recognizes a protein present in centrosomes.

MATERNALLY INFLUENCED EMBRYONIC LETHALITY: ALLELE SPECIFIC GENETIC RESCUE AT A FEMALE FERTILITY LOCUS IN DROSOPHILA MELANOGASTER

1976 ◽  
Vol 18 (4) ◽  
pp. 773-781 ◽  
Author(s):  
Patricia Romans ◽  
R. B. Hodgetts ◽  
D. Nash
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
X Chromosome ◽  
Maternal Effect ◽  
Female Offspring ◽  
The Other ◽  
Genetic Rescue ◽  
Homozygous Mutant ◽  
Allele Specific ◽  
Normal Males

A new locus, mel(l)R1, with a maternal effect on embryonic development, has been mapped at about 0.5 on the X chromosome of Drosophila melanogaster and localized cytologically between bands 2D6 and 3A1. Genotypically mutant embryos die if produced by homozygous mutant females but survive if produced by heterozygous females. Two mutant alleles have been isolated. One of these is genetically rescuable: when homozygous mutant females are mated to mutant males, all the embryos die, but when these females are mated to normal males, female offspring are produced. The other allele is not rescuable. Genetic rescue is dominant at this locus since females heterozygous for the two mutant alleles produce female offspring in crosses to normal males.

scholarly journals X-LINKED FEMALE-STERILE LOCI IN DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 113 (3) ◽  
pp. 695-712
Author(s):  
Norbert Perrimon ◽  
Dawson Mohler ◽  
Lee Engstrom ◽  
A P Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
X Chromosome ◽  
Maternal Effect ◽  
The Other ◽  
Drosophila Genome ◽  
Relative Contribution ◽  
Clone Analysis ◽  
Single Allele ◽  
Lethal Genes

ABSTRACT We have examined the number of X-linked loci specifically required only during oogenesis. Complementation analyses among female-sterile (fs) mutations obtained in two mutagenesis screens—Gans' and Mohler's—indicate that any fs locus represented by two or more mutant alleles in Gans' collection are usually present in Mohler's collection. However, when a locus is represented by a single allele in one collection, it is generally not present in the other collection. We propose that this discrepancy is due to the fact that most "fs loci" represented by less than two mutant alleles are, in fact, vital (zygotic lethal) genes, and that the fs alleles are hypomorphic mutations of such genes. In support of this hypothesis we have identified lethal alleles at 12 of these "fs loci." The present analysis has possibly identified all maternal-effect lethal loci detectable by mutations on the X chromosome and has allowed us to reevaluate the number of "ovary-specific fs" loci in the Drosophila genome. Finally, germline clone analysis of a large number of fs mutations was performed in order to estimate the relative contribution of germline and somatic cell derivatives to oogenesis and to embryonic development. All the maternal-effect lethal loci tested are germline-dependent.

The nullo protein is a component of the actin-myosin network that mediates cellularization in Drosophila melanogaster embryos

1994 ◽  
Vol 107 (7) ◽  
pp. 1863-1873 ◽  
Author(s):  
M.A. Postner ◽  
E.F. Wieschaus
Keyword(s):  
Drosophila Melanogaster ◽  
Monoclonal Antibodies ◽  
Plasma Membrane ◽  
Nuclear Division ◽  
Leading Edge ◽  
The Other ◽  
Drosophila Embryogenesis ◽  
Zygotic Transcription ◽  
Hexagonal Network

After the 13th nuclear division cycle of Drosophila embryogenesis, cortical microfilaments are reorganized into a hexagonal network that drives the subsequent cellularization of the syncytial embryo. Zygotic transcription of the nullo and serendipity-alpha genes is required for normal structuring of the microfilament network. When either gene is deleted, the network assumes an irregular configuration leading to the formation of multinucleate cells. To investigate the role of these genes during cellularization, we have made monoclonal antibodies to both proteins. The nullo protein is present from cycle 13 through the end of cellularization. During cycle 13, it localizes between interphase actin caps and within metaphase furrows. In cellularizing embryos, nullo co-localizes with the actin-myosin network and invaginates along with the leading edge of the plasma membrane. The serendipity-alpha (sry-alpha) protein co-localizes with nullo protein to the hexagonal network but, unlike the nullo protein, it localizes to the sides rather than the vertices of each hexagon. Mutant embryos demonstrate that neither protein translationally regulates the other, but the localization of the sry-alpha protein to the hexagonal network is dependent upon nullo.

The Localization of β-Glucuronidase in the Early Chick Embryo

Development ◽  
1958 ◽  
Vol 6 (1) ◽  
pp. 52-56
Author(s):  
F. Billett ◽  
Leela Mulherkar
Keyword(s):  
Drosophila Melanogaster ◽  
Chick Embryo ◽  
Embryonic Development ◽  
Xenopus Laevis ◽  
Mouse Liver ◽  
Histochemical Method ◽  
Toxic Compounds ◽  
Early Chick Embryo ◽  
Early Embryos ◽  
Drosophila Embryos

In vertebrate tissues there appears to be a connexion between β-glucuronidase and the proliferation of cells. This connexion was first noticed by Levvy, Kerr, & Campbell (1948) when they were investigating the effect of toxic compounds on mouse-liver glucuronidase. The early stages of embryonic development are characterized by rapid proliferations of cells and it is, therefore, of some interest to study the localization of β-glucuronidase during these stages. Small amounts of β-glucuronidase can be detected in the early embryos of Xenopus laevis (Billett, 1956) and in those of Drosophila melanogaster (Billett & Counce, unpublished). In these embryos no marked increase in the enzyme can be associated with the proliferation of cells. The large amount of yolk in the Xenopus and Drosophila embryos was a complicating factor in the above experiments. It was not possible to localize the enzyme in these embryos with a histochemical method.

Live Confocal Analysis of Fertilization and Early Development

2001 ◽  
Vol 7 (S2) ◽  
pp. 1012-1013
Author(s):  
Uyen Tram ◽  
William Sullivan
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
Real Time ◽  
Early Development ◽  
Fluorescent Probes ◽  
Primary Defect ◽  
Fluorescent Analysis ◽  
Dynamic Event ◽  
Enormous Amount ◽  
Fluorescent Studies

Embryonic development is a dynamic event and is best studied in live animals in real time. Much of our knowledge of the early events of embryogenesis, however, comes from immunofluourescent analysis of fixed embryos. While these studies provide an enormous amount of information about the organization of different structures during development, they can give only a static glimpse of a very dynamic event. More recently real-time fluorescent studies of living embryos have become much more routine and have given new insights to how different structures and organelles (chromosomes, centrosomes, cytoskeleton, etc.) are coordinately regulated. This is in large part due to the development of commercially available fluorescent probes, GFP technology, and newly developed sensitive fluorescent microscopes. For example, live confocal fluorescent analysis proved essential in determining the primary defect in mutations that disrupt early nuclear divisions in Drosophila melanogaster. For organisms in which GPF transgenics is not available, fluorescent probes that label DNA, microtubules, and actin are available for microinjection.

Use of monoclonal and polyclonal antibodies to detect prostatic acid phosphatase by immunoblotting.

1986 ◽  
Vol 32 (10) ◽  
pp. 1832-1835 ◽  
Author(s):  
P C Patel ◽  
L Aubin ◽  
J Côte
Keyword(s):  
Monoclonal Antibodies ◽  
Acid Phosphatase ◽  
Western Blot ◽  
Polyclonal Antibodies ◽  
Prostatic Acid Phosphatase ◽  
The Other ◽  
Dot Blot ◽  
Western Blots ◽  
Dot Blot Assay ◽  
Polyclonal Antisera

Abstract We investigated two techniques of immunoblotting--the Western blot and the dot blot--for use in detecting prostatic acid phosphatase (PAP, EC 3.1.3.2). We used polyclonal antisera to human PAP, produced in rabbits by hyperimmunization with purified PAP, and PAP-specific monoclonal antibodies in the immunoenzymatic protocols. We conclude that PAP can be readily detected by Western blots with use of polyclonal antisera, but not with monoclonal antibodies. On the other hand, using a dot blot assay, we could easily detect PAP with both polyclonal and monoclonal antibodies.

scholarly journals Single and mixed exposure to cadmium and mercury in Drosophila melanogaster: Molecular responses and impact on post-embryonic development

2021 ◽  
Vol 220 ◽  
pp. 112377
Author(s):  
Laëtitia Frat ◽  
Thomas Chertemps ◽  
Élise Pesce ◽  
Françoise Bozzolan ◽  
Matthieu Dacher ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
Molecular Responses ◽  
Mixed Exposure

scholarly journals Transvection at the End of the Truncated Chromosome in Drosophila melanogaster

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1375-1387
Author(s):  
Mikhail Savitsky ◽  
Tatyana Kahn ◽  
Ekaterina Pomerantseva ◽  
Pavel Georgiev
Keyword(s):  
Drosophila Melanogaster ◽  
Homologous Chromosome ◽  
Regulatory Region ◽  
Proximal Region ◽  
The Other ◽  
Upstream Region ◽  
Upstream Sequence ◽  
Transcription Start ◽  
Promoter Proximal Region

Abstract The phenomenon of transvection is well known for the Drosophila yellow locus. Thus enhancers of a promoterless yellow locus in one homologous chromosome can activate the yellow promoter in the other chromosome where the enhancers are inactive or deleted. In this report, we examined the requirements for trans-activation of the yellow promoter at the end of the deficient chromosome. A number of truncated chromosomes ending in different areas of the yellow regulatory region were examined in combination with the promoterless y alleles. We found that trans-activation of the yellow promoter at the end of a deficient chromosome required ∼6 kb of an additional upstream sequence. The nature of upstream sequences affected the strength of transvection: addition of gypsy sequences induced stronger trans-activation than addition of HeT-A or yellow sequences. Only the promoter proximal region (within -158 bp of the yellow transcription start) was essential for trans-activation; i.e., transvection did not require extensive homology in the yellow upstream region. Finally, the yellow enhancers located on the two pairing chromosomes could cooperatively activate one yellow promoter.

THE MOLECULAR ORGANIZATION OF HUMAN ALPHA 2-MACROGLOBULIN. AN IMMUNO ELECTRON MICROSCOPIC STUDY WITH MONOCLONAL ANTIBODIES

1987 ◽  
Author(s):  
E Delain ◽  
M Barrav ◽  
J Tapon-Bretaudière ◽  
F Pochon ◽  
F Van Leuven
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Sites ◽  
Divalent Cations ◽  
The Other ◽  
Molecular Organization ◽  
Cellular Receptor ◽  
Electron Microscopic ◽  
Microscopic Method ◽  
Bait Region ◽  
Electron Microscopic Method

Electron microscopy is a very convenient method to localize the epitopes of monoclonal antibodies (mAbs) at the surface of macromolecules for studying their tree-dimensional organization.We applied this immuno-electron microscopic method to human ct2-macroglobulin (ct2M). 29 anti-α2M mAbs have been tested with the four different forms of a2M : native and chymotrypsin-transformed tetramers, and the corresponding dimers, obtained by dissociation with divalent cations. These mAbs can be classified in three types : those which are specific for 1) the H-like transformed molecules, 2) the native molecules, and 3) those which can react with both forms of α2M.1) Among the H-like α2M specific mAbs, several react with the 20 kD-domain which is recognized by the cellular receptor of transformed a2M. This domain is located at the carboxyterminal end of each monomer. One IgG binds to the end of two adjacent tips of the H-like form.The other mAbs of this type bind to the α2M tips at non-terminal positions. Intermolecular connections built polymers of alternating α2M and IgG molecules.2) Among the native a2M-specific mAbs some are able to inhibit the protease-induced transformation of the native α2M. The binding sites of these mAbs are demonstrated on the native half-molecules. One of these mAbs was also able to react with transformed dimers, in a region corresponding very likely to an inaccessible epitope in the tetrameric transformed α2M molecule.3) Among the mAbs of this type, only two were able to inhibit the protease-induced transformation of α2M. Obviously, their epitopes should be close to the bait region of α2M. The other mAbs reacting with both α2M forms did not inhibit the α2M transformation.All these mAbs can be distinguished by the structure of the immune complexes formed with all forms of α2M. The epitopes are more easily located on the dimers and on the H-like transformed α2M than on the native molecules.From these observations, we propose a new model of the tree-dimensional organization of the human α2M in its native and transformed configurations, and of its protease-induced transformation.

scholarly journals IgA: Structure, Function, and Developability

Antibodies ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 57 ◽  
Author(s):  
Patrícia de Sousa-Pereira ◽  
Jenny M. Woof
Keyword(s):  
Monoclonal Antibodies ◽  
Structure Function ◽  
Immunoglobulin A ◽  
Structural Features ◽  
The Other ◽  
Immune Defence ◽  
Major Site ◽  
Mucosal Surfaces ◽  
Serum Iga ◽  
Antibody Class

Immunoglobulin A (IgA) plays a key role in defending mucosal surfaces against attack by infectious microorganisms. Such sites present a major site of susceptibility due to their vast surface area and their constant exposure to ingested and inhaled material. The importance of IgA to effective immune defence is signalled by the fact that more IgA is produced than all the other immunoglobulin classes combined. Indeed, IgA is not just the most prevalent antibody class at mucosal sites, but is also present at significant concentrations in serum. The unique structural features of the IgA heavy chain allow IgA to polymerise, resulting in mainly dimeric forms, along with some higher polymers, in secretions. Both serum IgA, which is principally monomeric, and secretory forms of IgA are capable of neutralising and removing pathogens through a range of mechanisms, including triggering the IgA Fc receptor known as FcαRI or CD89 on phagocytes. The effectiveness of these elimination processes is highlighted by the fact that various pathogens have evolved mechanisms to thwart such IgA-mediated clearance. As the structure–function relationships governing the varied capabilities of this immunoglobulin class come into increasingly clear focus, and means to circumvent any inherent limitations are developed, IgA-based monoclonal antibodies are set to emerge as new and potent options in the therapeutic arena.

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