Identification of vimentin and novel vimentin-related proteins in Xenopus oocytes and early embryos

Development ◽  
1990 ◽  
Vol 110 (4) ◽  
pp. 1185-1195
Author(s):  
N.P. Torpey ◽  
J. Heasman ◽  
C.C. Wylie
Keyword(s):  
Fusion Proteins ◽  
Xenopus Oocytes ◽  
Germ Plasm ◽  
Radial Glial Cells ◽  
Larval Stages ◽  
Early Embryos ◽  
Radial Glial ◽  
Synthetic Mrna ◽  
Related Proteins ◽  
First Time

We have made antibodies against fusion proteins of Xenopus vimentin. We show for the first time the distribution of vimentin in larval stages, where it is found in cells of mesenchymal origin, and in radial glial cells. In sections of Xenopus oocytes and early embryos, immunocytochemistry reveals the presence of an extensive cytoplasmic network, distributed in an animal-vegetal gradient. Germ plasm stains particularly strongly. The form of the IF proteins in this network is unusual. In immunoblot experiments the anti-vimentin antibodies detect a number of distinct proteins. We have identified those that are the products of the two known vimentin genes, by injection of synthetic mRNA transcribed from cloned vimentin cDNAs into oocytes, followed by two-dimensional Western blotting. This has demonstrated unambiguously that one Xenopus vimentin, Vim1, is present in oocytes and early embryos. However, two other immunoreactive proteins detected in Triton extracts of oocytes and early embryos are not the products of Vim1, since depletion of vimentin mRNA by antisense oligonucleotide injection has no effect on the synthesis of these proteins. These results suggest that novel IF-like proteins are expressed in Xenopus oocytes and early embryos.

scholarly journals Distinct distribution of vimentin and cytokeratin in Xenopus oocytes and early embryos

1992 ◽  
Vol 101 (1) ◽  
pp. 151-160 ◽  
Author(s):  
N.P. Torpey ◽  
J. Heasman ◽  
C.C. Wylie
Keyword(s):  
Spinal Cord ◽  
Amino Acid ◽  
Xenopus Oocytes ◽  
Germ Plasm ◽  
Predicted Amino Acid Sequence ◽  
Larval Stages ◽  
Functional Differences ◽  
Early Embryos ◽  
Strong Staining ◽  
Distinct Distribution

We report the identity of a major component of Triton-insoluble extracts from Xenopus oocytes and early embryos. In a previous paper we showed that an antibody, Z9, cross-reacts with two polypeptides from such extracts (Mr 56,000 and 57,000) as well as Xenopus vimentin. Direct microsequencing of the Mr 57,000 protein shows near identity of three tryptic fragments with regions of the predicted amino acid sequence of XCK1(8), a basic cytokeratin whose mRNA is known to be expressed in Xenopus oocytes. We have raised an antibody, CK7, against a fusion protein generated from this cDNA. The specificity of this antibody has been tested using 1- and 2-dimensional immunoblotting, which show that it is specific for the Mr 56,000 and 57,000 proteins, suggesting that these two proteins may be the products of two non-allelic XCK1(8) genes. The antibody does not cross-react with vimentin. We have used CK7 to follow the distribution of XCK1(8) throughout development by immunoblotting and immunocytochemistry. In larval stages, strong staining is seen in the notocord, the apical epithelia of the gut, the mesentery, and a few cells in the spinal cord. In oocytes and early embryos, two distinct intermediate filament (IF) networks can be distinguished: a cortical cytokeratin network, and a deeper vimentin one. In addition, the oocyte germ plasm stains with Z9 but not CK7. We propose that such distinct distributions of each IF protein reflect functional differences during early development.

scholarly journals Full allogeneic fusion of embryos in a holothuroid echinoderm

2018 ◽  
Vol 285 (1879) ◽  
pp. 20180339 ◽  
Author(s):  
Bruno L. Gianasi ◽  
Jean-François Hamel ◽  
Annie Mercier
Keyword(s):  
Evolutionary Biology ◽  
Whole Body ◽  
Larval Stages ◽  
Early Embryos ◽  
Natural Tendency ◽  
Key Aspects ◽  
Cucumaria Frondosa ◽  
First Time ◽  
Direct Investigation ◽  
Colonial Organisms

Whole-body chimaeras (organisms composed of genetically distinct cells) have been directly observed in modular/colonial organisms (e.g. corals, sponges, ascidians); whereas in unitary deuterostosmes (including mammals) they have only been detected indirectly through molecular analysis. Here, we document for the first time the step-by-step development of whole-body chimaeras in the holothuroid Cucumaria frondosa , a unitary deuterostome belonging to the phylum Echinodermata. To the best of our knowledge, this is the most derived unitary metazoan in which direct investigation of zygote fusibility has been undertaken. Fusion occurred among hatched blastulae, never during earlier (unhatched) or later (larval) stages. The fully fused chimaeric propagules were two to five times larger than non-chimaeric embryos. Fusion was positively correlated with propagule density and facilitated by the natural tendency of early embryos to agglomerate. The discovery of natural chimaerism in a unitary deuterostome that possesses large externally fertilized eggs provides a framework to explore key aspects of evolutionary biology, histocompatibility and cell transplantation in biomedical research.

scholarly journals Associations of Phoretic Mites on Bark Beetles of the Genus Ips in the Black Sea Mountains of Turkey

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 516
Author(s):  
Cihan Cilbircioğlu ◽  
Marta Kovač ◽  
Milan Pernek
Keyword(s):  
Black Sea ◽  
Bark Beetles ◽  
Pinus Nigra ◽  
Mite Species ◽  
Tree Bark ◽  
The Black Sea ◽  
Forest Pests ◽  
Larval Stages ◽  
Suitable Habitats ◽  
First Time

Phoretic mites use bark beetles for transportation to new, suitable habitats. Some phoretic mites act as predators and parasitoids of the bark beetles’ immature stages, especially egg and early larval stages, and are potential agents for the biological control of scolytine forest pests. Mites live very frequently in relationships with other invertebrates. Many are found in association with various species of bark beetles. Here, a total of 41 specimens of different bark beetles of the genus Ips (Ips acuminatus, Ips sexdentatus and Ips typographus) were studied for presence, species composition, and abundance of phoretic mites. The beetles were collected on dead wood and parts of tree bark of Pinus nigra, Pinus sylvestris and Picea abies in the Black Sea Mountains in Kastamonu and Artin Province of Turkey. A total of nine mite species were found, including Dendrolaelaps quadrisetus, Ereynetes sp., Histiostoma piceae, Paraleius cf. leontonychus, Pleuronectocelaeno barbara., Proctolaelaps hystricoides, Schizostethus simulatrix, Trichouropoda lamellosa and Uroobovellaipidis. All species are identified for the first time within Turkish fauna.

XMAP230 is required for the assembly and organization of acetylated microtubules and spindles in Xenopus oocytes and eggs

1998 ◽  
Vol 111 (16) ◽  
pp. 2315-2327 ◽  
Author(s):  
B.J. Cha ◽  
B. Error ◽  
D.L. Gard
Keyword(s):  
Late Stage ◽  
Xenopus Oocytes ◽  
Early Stage ◽  
Polyclonal Antibodies ◽  
Stage Iv ◽  
Stage I ◽  
Meiotic Spindle ◽  
Heat Stable ◽  
Early Embryos ◽  
And Function

We used affinity-purified polyclonal antibodies to characterize the distribution and function of XMAP230, a heat-stable microtubule-associated protein isolated from Xenopus eggs, during oogenesis. Immunoblots revealed that XMAP230 was present throughout oogenesis and early development, but was most abundant in late stage oocytes, eggs, and early embryos. Immunofluorescence microscopy revealed that XMAP230 was associated with microtubules in oogonia, post-mitotic stage 0 oocytes, early stage I oocytes, and during stage IV-VI of oogenesis. However, staining of microtubules by anti-XMAP230 was not detectable during late stage I through stage III. In stage VI oocytes, anti-XMAP230 stained a large subset of microtubules that were also stained with monoclonal antibodies specific for acetylated (α)-tubulin. During oocyte maturation, XMAP230 was associated with the transient microtubule array that serves as the precursor of the first meiotic spindle, as well as both first and second meiotic spindles. The extensive array of cytoplasmic microtubules present throughout maturation was not detectably stained by anti-XMAP230. Microinjection of anti-XMAP230 locally disrupted the organization and acetylation of microtubules in stage VI oocytes, and reduced the re-acetylation of microtubules during recovery from cold-induced microtubule disassembly. Subsequent maturation of oocytes injected with anti-XMAP230 resulted in defects in the assembly of the transient microtubules array and first meiotic spindle. These observations suggest that XMAP230 is required for the stabilization and organization of cytoplasmic and spindle microtubules in Xenopus oocytes and eggs.

scholarly journals Microfluidic-based imaging of complete C. elegans larval development

2021 ◽  
Author(s):  
Simon Berger ◽  
Silvan Spiri ◽  
Andrew deMello ◽  
Alex Hajnal
Keyword(s):  
Imaging Method ◽  
Cover Glass ◽  
Vulval Development ◽  
C Elegans ◽  
Larval Stages ◽  
Seam Cell ◽  
Time Observation ◽  
On Chip ◽  
First Time

Several microfluidic-based methods for long-term C. elegans imaging have been introduced in recent years, allowing real-time observation of previously inaccessible processes. The ex-isting methods either permit imaging across multiple larval stages without maintaining a stable worm orientation, or allow for very good immobilization but are only suitable for shorter experiments. Here, we present a novel microfluidic imaging method, which allows parallel live-imaging across multiple larval stages, while delivering excellent immobilization and maintaining worm orientation and identity over time. This is achieved by employing an array of microfluidic trap channels carefully tuned to maintain worms in a stable orienta-tion, while allowing growth and molting to occur. Immobilization is supported by an active hydraulic valve, which presses worms onto the cover glass during image acquisition, with the animals remaining free for most of an experiment. Excellent quality images can be ac-quired of multiple worms in parallel, with little impact of the imaging method on worm via-bility or developmental timing. The capabilities of this methodology are demonstrated by observing the hypodermal seam cell divisions and, for the first time, the entire process of vulval development from induction to the end of morphogenesis. Moreover, we demonstrate RNAi on-chip, which allows for perturbation of dynamic developmental processes, such as basement membrane breaching during anchor cell invasion.

scholarly journals Crucial Roles of the Arp2/3 Complex during Mammalian Corticogenesis

2015 ◽  
Author(s):  
Pei-Shan Wang ◽  
Fu-Sheng Chou ◽  
Fengli Guo ◽  
Praveen Suraneni ◽  
Sheng Xia ◽  
...  
Keyword(s):  
Cell Fate ◽  
Membrane Trafficking ◽  
Neuronal Migration ◽  
Neuronal Cell ◽  
Leading Edge ◽  
Radial Glial Cells ◽  
A Cell ◽  
Radial Glial ◽  
Altered Cell ◽  
Actin Nucleator

The polarity and organization of radial glial cells (RGCs), which serve as both stem cells and scaffolds for neuronal migration, are crucial for cortical development. However, the cytoskeletal mechanisms that drive radial glial outgrowth and maintain RGC polarity remain poorly understood. Here, we show that the Arp2/3 complex, the unique actin nucleator that produces branched actin networks, plays essential roles in RGC polarity and morphogenesis. Disruption of the Arp2/3 complex in RGCs retards process outgrowth toward the basal surface and impairs apical polarity and adherens junctions. Whereas the former is correlated with abnormal actin-based leading edge, the latter is consistent with blockage in membrane trafficking. These defects result in altered cell fate, disrupted cortical lamination and abnormal angiogenesis. In addition, we present evidence that the Arp2/3 complex is a cell-autonomous regulator of neuronal migration. Our data suggest that Arp2/3-mediated actin assembly may be particularly important for neuronal cell motility in soft or poorly adhesive matrix environment.

scholarly journals Mutator Foci Are Regulated by Developmental Stage, RNA, and the Germline Cell Cycle in Caenorhabditis elegans

2020 ◽  
Vol 10 (10) ◽  
pp. 3719-3728 ◽  
Author(s):  
Celja J. Uebel ◽  
Dana Agbede ◽  
Dylan C. Wallis ◽  
Carolyn M. Phillips
Keyword(s):  
Cell Cycle ◽  
Caenorhabditis Elegans ◽  
Epigenetic Inheritance ◽  
Germline Cell ◽  
Late Pachytene ◽  
Larval Stages ◽  
Transcriptional Inhibition ◽  
Male Germline ◽  
Early Embryos ◽  
Adult Hermaphrodite

RNA interference is a crucial gene regulatory mechanism in Caenorhabditis elegans. Phase-separated perinuclear germline compartments called Mutator foci are a key element of RNAi, ensuring robust gene silencing and transgenerational epigenetic inheritance. Despite their importance, Mutator foci regulation is not well understood, and observations of Mutator foci have been largely limited to adult hermaphrodite germlines. Here we reveal that punctate Mutator foci arise in the progenitor germ cells of early embryos and persist throughout all larval stages. They are additionally present throughout the male germline and in the cytoplasm of post-meiotic spermatids, suggestive of a role in paternal epigenetic inheritance. In the adult germline, transcriptional inhibition results in a pachytene-specific loss of Mutator foci, indicating that Mutator foci are partially reliant on RNA for their stability. Finally, we demonstrate that Mutator foci intensity is modulated by the stage of the germline cell cycle and specifically, that Mutator foci are brightest and most robust in the mitotic cells, transition zone, and late pachytene of adult germlines. Thus, our data defines several new factors that modulate Mutator foci morphology which may ultimately have implications for efficacy of RNAi in certain cell stages or environments.

scholarly journals Associations of Phoretic Mites on Bark Beetles of the Genus Ips in the Black Sea Mountains of Turkey

2021 ◽  
Author(s):  
Cihan Cilbircioğlu ◽  
Marta Matek Kovač ◽  
Milan Pernek
Keyword(s):  
Black Sea ◽  
Bark Beetles ◽  
Pinus Nigra ◽  
Mite Species ◽  
Tree Bark ◽  
The Black Sea ◽  
Forest Pests ◽  
Larval Stages ◽  
Suitable Habitats ◽  
First Time

Phoretic mites use bark beetles for transportation to new, suitable habitats. Some phoretic mites act as predators and parasitoids of the bark beetles’ immature stages, especially egg and early larval stages, and are potential agents for the biological control of scolytine forest pests. One of the most numerous and largest mite orders is Mesostigmata which live very frequently in relationships with other invertebrates. Many are found in association with various species of bark beetles. Here, a total of 41 specimens of different bark beetles of the genus Ips (I. acuminatus, I. sexdentatus and I. typographus) were studied for presence, species composition, and abundance of phoretic mites. The beetles were collected on dead wood and parts of tree bark of Pinus nigra, P. slyvestris and Picea abies in the Black Sea Mountains in Kastamonu and Artin Province of Turkey. A total of 9 mite species in 2 genera were found, including Dendrolaelaps quadrisetus, Ereynetes sp., Histiostoma piceae, Paraleius cf. leontonychus, Pleuronectocaeleno barbara., Proctolaelaps hystricoides, Schizostethus simulatrix, Trichouropoda lamellosa and Urobovella ipidis. All species and genera are identified for the first time within Turkish fauna.

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