The role of the glycoconjugates in the migration of anuran amphibian germ cells

Development ◽  
1984 ◽  
Vol 82 (1) ◽  
pp. 119-129
Author(s):  
M. Delbos ◽  
J.-D. Gipouloux ◽  
N. Saidi
Keyword(s):  
Germ Cells ◽  
Ultrastructural Study ◽  
Extracellular Space ◽  
Fluorescein Isothiocyanate ◽  
Follicular Cells ◽  
Migratory Activity ◽  
Anuran Amphibian ◽  
Arachis Hypogea ◽  
Pna Lectin

1. The presence of a large amount of glycoconjugates on the anuran amphibian germ cells was demonstrated using fluorescein isothiocyanate lectins binding specifically to D-galactose and at a lower level, by other lectins binding specifically to N-acetyl-galactosamine. 2. Glycoconjugates including D-galactose were found near the pseudopodial expansions and in the extracellular space, between germ cells and follicular cells. They were also disseminated in the cytoplasm. 3. The injection of PNA lectin (from Arachis hypogea) into the endoderm inhibited the migration of 90 % of the germ cells. This inhibition was lectin-concentration dependent. Ultrastructural study of germ cells, the migration of which was inhibited, showed that they were degenerating. These results suggest that glycoconjugates are related to the migratory activity of germ cells.

Scanning electron microscopic study of collagen fibrillogenesis and extracellular compartmentalization in the chick embryo tendon

1986 ◽  
Vol 44 ◽  
pp. 208-209
Author(s):  
Grace C.H. Yang
Keyword(s):  
Chick Embryo ◽  
Extracellular Space ◽  
Fibroblast Cell ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Voltage Electron ◽  
Scanning Electron Microscopic Study ◽  
Microscopic Studies ◽  
And Function

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.

Interspecific variation of zona pellucida glycoconjugates in several species of marsupial

Reproduction ◽  
2000 ◽  
pp. 111-120 ◽  
Author(s):  
JA Chapman ◽  
OW Wiebkin ◽  
WG Breed
Keyword(s):  
Glycine Max ◽  
Sialic Acid ◽  
Zona Pellucida ◽  
Fluorescein Isothiocyanate ◽  
Interspecific Variation ◽  
Lectin Histochemistry ◽  
Sialic Acids ◽  
Arachis Hypogea ◽  
Marsupial Species ◽  
Similar Intensity

The zona pellucida glycoconjugate content of several marsupial species was investigated using differential lectin histochemistry. Ovaries from fat-tailed dunnarts, a southern brown bandicoot, grey short-tailed opossums, brushtail possums, ringtail possums, koalas and eastern grey kangaroos were fixed, embedded in paraffin wax, sectioned and stained with ten fluorescein isothiocyanate-conjugated lectins. Sections were also incubated with either neuraminidase or saponified, respectively, before incubation with the lectins to identify saccharide residues masked by sialic acids or O-acetyl groups on sialic acids. The zonae pellucidae surrounding the oocytes of the marsupials demonstrated interspecific variation in glycoconjugate content, with mannose-containing glycoconjugates exhibiting the greatest variation. Some of the zona pellucida glycoconjugates of all species, except those of the opossums, were masked by sialic acid with an increase in fluorescence with lectins from Arachis hypogea (PNA), and Glycine max (SBA), after desialylation. The disaccharide beta-galactose(1-4)N-acetyl-D-glucosamine appeared to be conformationally masked by O-acetyl groups of sialic acids in the zonae pellucidae of all species, with an increase in fluorescence with the lectin from Erythrina cristagalli (ECA), after saponification. Similar intensity and localization of beta-(1-4)-N-acetyl-D-glucosamine, as shown by staining of the lectin from Triticum vulgaris (WGA), to the inner and outer regions of the zona pellucida, were found to those reported in eutherian species. WGA fluorescence became uniform throughout the zonae pellucidae after saponification, indicating differential O-acetylation of sialic acids on the internal compartment of the zonae pellucidae.

scholarly journals Experimental research Concomitant protective and therapeutic role of verapamil in chronic mercury induced nephrotoxicity in the adult rat: histological, morphometric and ultrastructural study

2015 ◽  
Vol 1 ◽  
pp. 199-209 ◽  
Author(s):  
Nabila Yousef Abdel Haleem ◽  
Hoda Mahmoud El-Aasar ◽  
Sherif Mohamed Zaki ◽  
Sherif Mohamed Sabry ◽  
Ahmed Wafiq El-Zainy
Keyword(s):  
Experimental Research ◽  
Ultrastructural Study ◽  
Therapeutic Role ◽  
Adult Rat

scholarly journals Genomic imprinting in germ cells: imprints are under control

Reproduction ◽  
2010 ◽  
Vol 140 (3) ◽  
pp. 411-423 ◽  
Author(s):  
Philippe Arnaud
Keyword(s):  
Dna Methylation ◽  
Genomic Imprinting ◽  
Germ Cells ◽  
Imprinted Genes ◽  
Regulatory Sequences ◽  
Sequence Specificity ◽  
Maternal Allele ◽  
Primary Sequence ◽  
Chromatin Configuration

The cis-acting regulatory sequences of imprinted gene loci, called imprinting control regions (ICRs), acquire specific imprint marks in germ cells, including DNA methylation. These epigenetic imprints ensure that imprinted genes are expressed exclusively from either the paternal or the maternal allele in offspring. The last few years have witnessed a rapid increase in studies on how and when ICRs become marked by and subsequently maintain such epigenetic modifications. These novel findings are summarised in this review, which focuses on the germline acquisition of DNA methylation imprints and particularly on the combined role of primary sequence specificity, chromatin configuration, non-histone proteins and transcriptional events.

zfh-1 is required for germ cell migration and gonadal mesoderm development in Drosophila

Development ◽  
1998 ◽  
Vol 125 (4) ◽  
pp. 655-666 ◽  
Author(s):  
H.T. Broihier ◽  
L.A. Moore ◽  
M. Van Doren ◽  
S. Newman ◽  
R. Lehmann
Keyword(s):  
Cell Migration ◽  
Germ Cell ◽  
Germ Cells ◽  
Ectopic Expression ◽  
Homeodomain Protein ◽  
Mesoderm Development ◽  
Visceral Mesoderm ◽  
Temporal Course ◽  
Germ Cell Migration

In Drosophila as well as many vertebrate systems, germ cells form extraembryonically and migrate into the embryo before navigating toward gonadal mesodermal cells. How the gonadal mesoderm attracts migratory germ cells is not understood in any system. We have taken a genetic approach to identify genes required for germ cell migration in Drosophila. Here we describe the role of zfh-1 in germ cell migration to the gonadal mesoderm. In zfh-1 mutant embryos, the initial association of germ cells and gonadal mesoderm is blocked. Loss of zfh-1 activity disrupts the development of two distinct mesodermal populations: the caudal visceral mesoderm and the gonadal mesoderm. We demonstrate that the caudal visceral mesoderm facilitates the migration of germ cells from the endoderm to the mesoderm. Zfh-1 is also expressed in the gonadal mesoderm throughout the development of this tissue. Ectopic expression of Zfh-1 is sufficient to induce additional gonadal mesodermal cells and to alter the temporal course of gene expression within these cells. Finally, through analysis of a tinman zfh-1 double mutant, we show that zfh-1 acts in conjunction with tinman, another homeodomain protein, in the specification of lateral mesodermal derivatives, including the gonadal mesoderm.

On the role of germ cells in planarian regeneration

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 53-63
Author(s):  
V. Gremigni ◽  
C. Miceli ◽  
I. Puccinelli
Keyword(s):  
Chromosome Number ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Karyological Analysis ◽  
Blastema Formation ◽  
Planarian Regeneration ◽  
Somatic Tissues ◽  
Caudal Area ◽  
Complete Regeneration

Specimens from a polyploid biotype of Dugesia lugubris s.l. were used to clarify the role and fate of germ cells during planarian regeneration. These specimens provide a useful karyological marker because embryonic and somatic cells (3n = 12) can be easily distinguished from male (2n = 8) and female (6n = 24) germ cells by their chromosome number. We succeed in demonstrating how primordial germ cells participate in blastema formation and take part in rebuilding somatic tissues. This evidence was obtained by cutting each planarian specimen twice at appropriate levels. The first aimed to induce primordial germ cells to migrate to the wound. The second cut was performed after complete regeneration and aimed to obtain a blastema from a cephalic or caudal area devoid of gonads. A karyological analysis of mitotic cells present in each blastema obtained after the second cut provided evidence that cells, originally belonging to the germ lines, are still present in somatic tissues even months after complete regeneration. The role of primordial germ cells in planarian regeneration was finally discussed in relation to the phenomenon of metaplasia or transdifferentiation.

Dual role of Ovol2 on the germ cell lineage segregation during gastrulation in mouse embryogenesis

Development ◽  
2022 ◽  
Author(s):  
Yuki Naitou ◽  
Go Nagamatsu ◽  
Nobuhiko Hamazaki ◽  
Kenjiro Shirane ◽  
Masafumi Hayashi ◽  
...  
Keyword(s):  
Germ Cells ◽  
Splice Variant ◽  
Epithelial To Mesenchymal Transition ◽  
Functional Relationship ◽  
Germ Line ◽  
Primordial Germ Cells ◽  
Cell Lineage ◽  
Animal Kingdom ◽  
Mesenchymal Transition

In mammals, primordial germ cells (PGCs), the origin of the germ line, are specified from the epiblast at the posterior region where gastrulation simultaneously occurs, yet the functional relationship between PGC specification and gastrulation remains unclear. Here, we show that Ovol2, a transcription factor conserved across the animal kingdom, balances these major developmental processes by repressing the epithelial-to-mesenchymal transition (EMT) driving gastrulation and the upregulation of genes associated with PGC specification. Ovol2a, a splice variant encoding a repressor domain, directly regulates EMT-related genes and consequently induces re-acquisition of potential pluripotency during PGC specification, whereas Ovol2b, another splice variant missing the repressor domain, directly upregulates genes associated with PGC specification. Taken together, these results elucidate the molecular mechanism underlying allocation of the germ line among epiblast cells differentiating into somatic cells through gastrulation.

CCM3 Loss-Induced Lymphatic Defect Is Mediated by the Augmented VEGFR3-ERK1/2 Signaling

2021 ◽  
Author(s):  
Lingfeng Qin ◽  
Haifeng Zhang ◽  
Busu Li ◽  
Quan Jiang ◽  
Francesc Lopez ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Fluorescein Isothiocyanate ◽  
The Body ◽  
Blue Dye ◽  
Transcriptional Level ◽  
Dependent Manner ◽  
Cavernous Malformations ◽  
Morphological Alterations ◽  
The Brain

Objective: Cerebral cavernous malformations (CCMs) can happen anywhere in the body, although they most commonly produce symptoms in the brain. The role of CCM genes in other vascular beds outside the brain and retina is not well-examined, although the 3 CCM-associated genes ( CCM1 , CCM2 , and CCM3 ) are ubiquitously expressed in all tissues. We aimed to determine the role of CCM gene in lymphatics. Approach and Results: Mice with an inducible pan–endothelial cell (EC) or lymphatic EC deletion of Ccm3 ( Pdcd10 ECKO or Pdcd10 LECKO ) exhibit dilated lymphatic capillaries and collecting vessels with abnormal valve structure. Morphological alterations were correlated with lymphatic dysfunction in Pdcd10 LECKO mice as determined by Evans blue dye and fluorescein isothiocyanate(FITC)-dextran transport assays. Pdcd10 LECKO lymphatics had increased VEGFR3 (vascular endothelial growth factor receptor-3)-ERK1/2 signaling with lymphatic hyperplasia. Mechanistic studies suggested that VEGFR3 is primarily regulated at a transcriptional level in Ccm3-deficient lymphatic ECs, in an NF-κB (nuclear factor κB)–dependent manner. CCM3 binds to importin alpha 2/KPNA2 (karyopherin subunit alpha 2), and a CCM3 deletion releases KPNA2 to activate NF-κB P65 by facilitating its nuclear translocation and P65-dependent VEGFR3 transcription. Moreover, increased VEGFR3 in lymphatic EC preferentially activates ERK1/2 signaling, which is critical for lymphatic EC proliferation. Importantly, inhibition of VEGFR3 or ERK1/2 rescued the lymphatic defects in structure and function. Conclusions: Our data demonstrate that CCM3 deletion augments the VEGFR3-ERK1/2 signaling in lymphatic EC that drives lymphatic hyperplasia and malformation and warrant further investigation on the potential clinical relevance of lymphatic dysfunction in patients with CCM.

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