Analysis of clonal restriction of cell mingling in Xenopus

1985 ◽  
Vol 312 (1153) ◽  
pp. 57-65 ◽  
Keyword(s):  
Horseradish Peroxidase ◽  
Cell Types ◽  
Cell Group ◽  
Cell Stage ◽  
Wide Range ◽  
Cell Groups ◽  
Cell Layers ◽  
Single Blastomeres

Cell fates were traced by injecting horseradish peroxidase into single blastomeres of Xenopus embryos at 2- to 512-cell stages. At later stages the number, types and locations of all labelled progeny were observed. Progeny of a single labelled ancestral cell divided coherently until the 12th cell generation, the onset of gastrulation, and then dispersed and mingled with unlabelled cells. Cell mingling was restricted at mediolateral and anterior—posterior boundaries. These boundaries were always respected by progeny of any blastomere labelled at the 512-cell stage but they were frequently crossed by progeny of blastomeres labelled at the 256-cell or earlier stages. The boundaries defined seven morphological compartments each populated exclusively by a group of ancestral cells at the 512-cell stage. Each blastomere that contributed progeny to the nervous system also gave rise to a wide range of cell types in all three primary germ cell layers but the clone was restricted to a single compartment. Analysis of clonal restriction of cell mingling was done in vitro . Twenty to thirty blastomeres were excised from one ancestral cell group at the 512-cell stage and combined in vitro with 20-30 blastomeres from another group. One group of blastomeres labelled with horseradish peroxidase was placed in contact with another group of unlabelled blastomeres, maintained in vitro for up to 2 days, and then processed histologically to show the distribution of labelled and unlabelled cells. Mingling was significantly greater in combinations of two of the same ancestral cell groups than in combinations of two different ancestral cell groups. A similar result was observed when a single labelled cell was combined with either the same or different ancestral cells. In all experiments the cells were significantly larger in combinations of different ancestral cell groups, indicating that they had undergone fewer divisions. These results are consistent with the hypothesis that boundaries observed in vivo are lines of clonal restriction formed by mutual inhibition of cell motility and cell division following contact between progeny of different ancestral cell groups.

Mcl-1 in Transgenic Mice Promotes Survival in a Spectrum of Hematopoietic Cell Types and Immortalization in the Myeloid Lineage

Blood ◽  
1998 ◽  
Vol 92 (9) ◽  
pp. 3226-3239 ◽  
Author(s):  
Ping Zhou ◽  
Liping Qian ◽  
Christine K. Bieszczad ◽  
Randolph Noelle ◽  
Michael Binder ◽  
...  
Keyword(s):  
Myeloid Cells ◽  
Myeloid Cell ◽  
Cell Types ◽  
Cell Number ◽  
Hematopoietic Cell ◽  
Viable Cell Number ◽  
Wide Range ◽  
Transgenic Cells

Abstract Mcl-1 is a member of the Bcl-2 family that is expressed in early monocyte differentiation and that can promote viability on transfection into immature myeloid cells. However, the effects of Mcl-1 are generally short lived compared with those of Bcl-2 and are not obvious in some transfectants. To further explore the effects of this gene, mice were produced that expressed Mcl-1 as a transgene in hematolymphoid tissues. The Mcl-1 transgene was found to cause moderate viability enhancement in a wide range of hematopoietic cell types, including lymphoid (B and T) as well as myeloid cells at both immature and mature stages of differentiation. However, enhanced hematopoietic capacity in transgenic bone marrow and spleen was not reflected in any change in pool sizes in the peripheral blood. In addition, among transgenic cells, mature T cells remained long lived compared with B cells and macrophages could live longer than either of these. Interestingly, when hematopoietic cells were maintained in tissue culture in the presence of interleukin-3, Mcl-1 enhanced the probability of outgrowth of continuously proliferating myeloid cell lines. Thus, Mcl-1 transgenic cells remained subject to normal in vivo homeostatic mechanisms controlling viable cell number, but these constraints could be overridden under specific conditions in vitro. Within the organism, Bcl-2 family members may act at “viability gates” along the differentiation continuum, functioning as part of a system for controlled hematopoietic cell amplification. Enforced expression of even a moderate viability-promoting member of this family such as Mcl-1, within a conducive intra- and extracellular environment in isolation from normal homeostatic constraints, can substantially increase the probability of cell immortalization. © 1998 by The American Society of Hematology.

Mcl-1 in Transgenic Mice Promotes Survival in a Spectrum of Hematopoietic Cell Types and Immortalization in the Myeloid Lineage

Blood ◽  
1998 ◽  
Vol 92 (9) ◽  
pp. 3226-3239 ◽  
Author(s):  
Ping Zhou ◽  
Liping Qian ◽  
Christine K. Bieszczad ◽  
Randolph Noelle ◽  
Michael Binder ◽  
...  
Keyword(s):  
Myeloid Cells ◽  
Myeloid Cell ◽  
Cell Types ◽  
Cell Number ◽  
Hematopoietic Cell ◽  
Viable Cell Number ◽  
Wide Range ◽  
Transgenic Cells

Mcl-1 is a member of the Bcl-2 family that is expressed in early monocyte differentiation and that can promote viability on transfection into immature myeloid cells. However, the effects of Mcl-1 are generally short lived compared with those of Bcl-2 and are not obvious in some transfectants. To further explore the effects of this gene, mice were produced that expressed Mcl-1 as a transgene in hematolymphoid tissues. The Mcl-1 transgene was found to cause moderate viability enhancement in a wide range of hematopoietic cell types, including lymphoid (B and T) as well as myeloid cells at both immature and mature stages of differentiation. However, enhanced hematopoietic capacity in transgenic bone marrow and spleen was not reflected in any change in pool sizes in the peripheral blood. In addition, among transgenic cells, mature T cells remained long lived compared with B cells and macrophages could live longer than either of these. Interestingly, when hematopoietic cells were maintained in tissue culture in the presence of interleukin-3, Mcl-1 enhanced the probability of outgrowth of continuously proliferating myeloid cell lines. Thus, Mcl-1 transgenic cells remained subject to normal in vivo homeostatic mechanisms controlling viable cell number, but these constraints could be overridden under specific conditions in vitro. Within the organism, Bcl-2 family members may act at “viability gates” along the differentiation continuum, functioning as part of a system for controlled hematopoietic cell amplification. Enforced expression of even a moderate viability-promoting member of this family such as Mcl-1, within a conducive intra- and extracellular environment in isolation from normal homeostatic constraints, can substantially increase the probability of cell immortalization. © 1998 by The American Society of Hematology.

scholarly journals Tissue engineering for compensating short bowel syndrome

2018 ◽  
Vol 20 (2) ◽  
pp. 259-264
Author(s):  
A V Kosulin ◽  
L N Beldiman ◽  
S V Kromsky ◽  
A A Kokorina ◽  
E V Mikhailova ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Small Intestine ◽  
Short Bowel Syndrome ◽  
Mechanical Stability ◽  
Clinical Problem ◽  
Cell Types ◽  
Short Bowel ◽  
Wide Range

Short bowel syndrome is an important clinical problem characterized by a high incidence of serious complications, deaths and socioeconomic consequences. Parenteral nutrition provides only a temporary solution without reducing the risk of complications. This applies equally to surgical treatment, in particular to small intestine transplantation and related concomitant interventions, which only facilitate the adaptation of the intestine to new conditions. Potential approaches have been analyzed in the treatment of the syndrome of the small intestine, which can be offered by dynamically developing tissue engineering. Various types of carriers and cell types that are used in experiments for obtaining tissue engineering designs of the intestine are discussed. A wide range of variants of such constructions is analyzed that can lead to obtaining an organ prosthesis with a cellular organization and mechanical stability similar to those of the native small intestine, which will ensure the necessary biocompatibility. It is established that one of the optimal carriers for today are extracellular matrices obtained by decellularization of the native small intestine. This process allows to preserve the microarchitecture of the small intestine, which greatly facilitates the process of filling the matrix with cells both in vitro and in vivo. It has also been established that mesenchymal stromal multipotent cells and organoid units obtained from the tissue of the native small intestine are particularly prominent among the most promising participants in the cellular ensemble.

scholarly journals Immature megakaryocytes in the mouse: physical characteristics, cell cycle status, and in vitro responsiveness to thrombopoietic stimulatory factor

Blood ◽  
1982 ◽  
Vol 59 (3) ◽  
pp. 569-575 ◽  
Author(s):  
MW Long ◽  
N Williams ◽  
S Ebbe
Keyword(s):  
Cell Cycle ◽  
Cell Types ◽  
Equilibrium Density ◽  
Early Maturation ◽  
Hydroxyurea Treatment ◽  
Cell Groups ◽  
Stimulatory Factor ◽  
Cell Cycle Status

Abstract The heterogeneity among immature megakaryocytes has been examined by physical properties, cell cycle status, and responsiveness to thrombopoietic stimulatory factor. Three types of immature megakaryocytes exist that can be recognized by acetylcholinesterase staining, nuclear shape, high nucleus/cytoplasm ratio, and small size (8--18 mu) with respect to mature megakaryocytes (greater than 18 mu). These three acetylcholinesterase-containing cell types are distinguished by their nuclear configuration: a round, indented, and lobed nucleus. The lobed cell type was found to overlap with and enhance detection of megakaryoblasts (stage I megakaryocytes). These cells had a sedimentation velocity range of 3.5--19.0 mm hr-1 and a density range of 1.072--1.095 g cm-3. Separation of these three classes of immature megakaryocytes was achieved by equilibrium density centrifugation with modal buoyant densities of 1.079 g cm-3 (round), 1.084 g cm-3 (indented), and 1.089 g cm-3 (lobed). In the presence of thrombopoietic stimulatory factor, the round nucleated cells, but not the indented or lobed nuclei morphology, were observed to develop into large mature megakaryocytes in 60-hr semisolid cell cultures. Development of two cell groups, or colonies of megakaryocytes, was not observed during this in vitro incubation period. In vivo treatment with hydroxyurea indicated that 57.5% +/- 19% of the round nucleus form were actively synthesizing DNA. No reduction in the numbers of indented or lobed nucleus forms were observed following hydroxyurea treatment. The data in this report strongly support the concept that these three types of immature megakaryocytes reflect the early maturation stages occurring in megakaryocyte differentiation.

Alteration of extracellular cation concentrations and ratios in culture medium does not affect first cleavage division of hamster zygotes in vitro nor overcome the 'two-cell block'

1989 ◽  
Vol 1 (3) ◽  
pp. 231 ◽  
Author(s):  
BD Bavister ◽  
M Golden
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Cell Block ◽  
Cleavage Division ◽  
Cell Stage ◽  
Wide Range ◽  
Standard Culture ◽  
Simple Medium

In vivo fertilized hamster one-cell eggs (embryos) were cultured in a simple medium that was modified to provide a wide range of concentrations and ratios of the four major cation components (sodium, potassium, calcium and magnesium) while maintaining total osmotic pressure at 290 +/- 5 mosm. Embryos were cultured in these media to find the optimum cation concentrations for supporting the first cleavage division in vitro and to determine if physiologically abnormal cation concentrations and/or ratios in standard culture media could account for the 'two-cell block' to development in vitro in this species. Despite using a broad range of ratios for sodium:potassium (from 45:1 to 5:1) and for calcium:magnesium (from 17:1 to 1:1), there were no significant differences in the proportions of fertilized eggs that underwent the first cleavage division (approx. 60-80% across all treatments), and none of the two-cell embryos underwent further cleavage during extended culture. These data demonstrate that the first cleavage division of hamster embryos in vitro is insensitive to extracellular concentrations and ratios of the major cations, and that the non-physiological concentrations and/or ratios of these cations in the culture medium are not the primary reason for the failure of hamster zygotes to develop past the two-cell stage in vitro.

scholarly journals Murine clusterin: molecular cloning and mRNA localization of a gene associated with epithelial differentiation processes during embryogenesis

1993 ◽  
Vol 122 (5) ◽  
pp. 1119-1130 ◽  
Author(s):  
LE French ◽  
A Chonn ◽  
D Ducrest ◽  
B Baumann ◽  
D Belin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Cell Types ◽  
Branching Morphogenesis ◽  
Structural Features ◽  
Heparin Binding ◽  
Binding Domains ◽  
Cell Layers

Clusterin is a broadly distributed glycoprotein constitutively expressed by various tissues and cell types, that has been shown to be involved in cell-cell adhesion and expressed during cellular differentiation in vitro. To assess the suggested participation of clusterin in these processes in vivo, we have cloned the cDNA encoding murine clusterin and studied the cellular distribution of clusterin mRNA during murine embryogenesis. Sequence analysis of the cDNA encoding murine clusterin revealed 92 and 75% sequence identity with the rat and human cDNAs, respectively, and conservation of the predicted structural features which include alpha-helical regions and heparin-binding domains. From 12.5 d of development onwards, the clusterin gene is widely expressed in developing epithelia, and selectively localized within the differentiating cell layers of tissues such as the developing skin, tooth, and duodenum where proliferating and differentiating compartments are readily distinguished. In addition, transient and localized clusterin gene expression was detected in certain morphogenetically active epithelia. In the lung, abundant gene transcripts were detected in cuboidal epithelial cells of the terminal lung buds during branching morphogenesis, and in the kidney, clusterin gene expression in the epithelial cells of comma and S-shaped bodies coincided with the process of polarization. Our results demonstrate the in vivo expression of the clusterin gene by differentiating epithelial cells during murine embryogenesis, and provide novel evidence suggesting that clusterin may be involved in the differentiation and morphogenesis of certain epithelia.

scholarly journals Immature megakaryocytes in the mouse: physical characteristics, cell cycle status, and in vitro responsiveness to thrombopoietic stimulatory factor

Blood ◽  
1982 ◽  
Vol 59 (3) ◽  
pp. 569-575 ◽  
Author(s):  
MW Long ◽  
N Williams ◽  
S Ebbe
Keyword(s):  
Cell Cycle ◽  
Cell Types ◽  
Equilibrium Density ◽  
Early Maturation ◽  
Hydroxyurea Treatment ◽  
Cell Groups ◽  
Stimulatory Factor ◽  
Cell Cycle Status

The heterogeneity among immature megakaryocytes has been examined by physical properties, cell cycle status, and responsiveness to thrombopoietic stimulatory factor. Three types of immature megakaryocytes exist that can be recognized by acetylcholinesterase staining, nuclear shape, high nucleus/cytoplasm ratio, and small size (8--18 mu) with respect to mature megakaryocytes (greater than 18 mu). These three acetylcholinesterase-containing cell types are distinguished by their nuclear configuration: a round, indented, and lobed nucleus. The lobed cell type was found to overlap with and enhance detection of megakaryoblasts (stage I megakaryocytes). These cells had a sedimentation velocity range of 3.5--19.0 mm hr-1 and a density range of 1.072--1.095 g cm-3. Separation of these three classes of immature megakaryocytes was achieved by equilibrium density centrifugation with modal buoyant densities of 1.079 g cm-3 (round), 1.084 g cm-3 (indented), and 1.089 g cm-3 (lobed). In the presence of thrombopoietic stimulatory factor, the round nucleated cells, but not the indented or lobed nuclei morphology, were observed to develop into large mature megakaryocytes in 60-hr semisolid cell cultures. Development of two cell groups, or colonies of megakaryocytes, was not observed during this in vitro incubation period. In vivo treatment with hydroxyurea indicated that 57.5% +/- 19% of the round nucleus form were actively synthesizing DNA. No reduction in the numbers of indented or lobed nucleus forms were observed following hydroxyurea treatment. The data in this report strongly support the concept that these three types of immature megakaryocytes reflect the early maturation stages occurring in megakaryocyte differentiation.

The allocation of early blastomeres to the ectoderm and endoderm is variable in the sea urchin embryo

Development ◽  
1997 ◽  
Vol 124 (11) ◽  
pp. 2213-2223 ◽  
Author(s):  
C.Y. Logan ◽  
D.R. McClay
Keyword(s):  
Sea Urchin ◽  
Low Frequency ◽  
Initial Step ◽  
Cell Types ◽  
Lytechinus Variegatus ◽  
Cell Fates ◽  
Cell Stage ◽  
Sea Urchin Embryo

During sea urchin development, a tier-to-tier progression of cell signaling events is thought to segregate the early blastomeres to five different cell lineages by the 60-cell stage (E. H. Davidson, 1989, Development 105, 421–445). For example, the sixth equatorial cleavage produces two tiers of sister cells called ‘veg1′ and ‘veg2,’ which were projected by early studies to be allocated to the ectoderm and endoderm, respectively. Recent in vitro studies have proposed that the segregation of veg1 and veg2 cells to distinct fates involves signaling between the veg1 and veg2 tiers (O. Khaner and F. Wilt, 1991, Development 112, 881–890). However, fate-mapping studies on 60-cell stage embryos have not been performed with modern lineage tracers, and cell interactions between veg1 and veg2 cells have not been shown in vivo. Therefore, as an initial step towards examining how archenteron precursors are specified, a clonal analysis of veg1 and veg2 cells was performed using the lipophilic dye, DiI(C16), in the sea urchin species, Lytechinus variegatus. Both veg1 and veg2 descendants form archenteron tissues, revealing that the ectoderm and endoderm are not segregated at the sixth cleavage. Also, this division does not demarcate cell type boundaries within the endoderm, because both veg1 and veg2 descendants make an overlapping range of endodermal cell types. The allocation of veg1 cells to ectoderm and endoderm during cleavage is variable, as revealed by both the failure of veg1 descendants labeled at the eighth equatorial division to segregate predictably to either tissue and the large differences in the numbers of veg1 descendants that contribute to the ectoderm. Furthermore, DiI-labeled mesomeres of 32-cell stage embryos also contribute to the endoderm at a low frequency. These results show that the prospective archenteron is produced by a larger population of cleavage-stage blastomeres than believed previously. The segregation of veg1 cells to the ectoderm and endoderm occurs relatively late during development and is unpredictable, indicating that later cell position is more important than the early cleavage pattern in determining ectodermal and archenteron cell fates.

scholarly journals IGF-binding protein-4: biochemical characteristics and functional consequences

2003 ◽  
Vol 178 (2) ◽  
pp. 177-193 ◽  
Author(s):  
R Zhou ◽  
D Diehl ◽  
A Hoeflich ◽  
H Lahm ◽  
E Wolf
Keyword(s):  
Biological Fluids ◽  
Biological Significance ◽  
Structural Similarity ◽  
Cell Types ◽  
Cellular Growth ◽  
Igf Binding Proteins ◽  
Wide Range ◽  
Igf Binding

IGFs have multiple functions regarding cellular growth, survival and differentiation under different physiological and pathological conditions. IGF effects are modulated systemically and locally by six high-affinity IGF-binding proteins (IGFBP-1 to -6). Despite their structural similarity, each IGFBP has unique properties and exhibits specific functions. IGFBP-4, the smallest IGFBP, exists in both non-glycosylated and N-glycosylated forms in all biological fluids. It is expressed by a wide range of cell types and tIssues, and its expression is regulated by different mechanisms in a cell type-specific manner. IGFBP-4 binds IGF-I and IGF-II with similar affinities and inhibits their actions under almost all in vitro and in vivo conditions. In this review, we summarize the available data regarding the following aspects of IGFBP-4: genomic organization, protein structure-function relationship, expression and its regulation, as well as IGF-dependent and -independent actions. The biological significance of IGFBP-4 for reproductive physiology, bone formation, renal pathophysiology and cancer is discussed.

The role of the zona pellucida in the development of mouse eggs in vivo

Development ◽  
1970 ◽  
Vol 23 (3) ◽  
pp. 539-547
Author(s):  
Jacek A. Modliński
Keyword(s):  
Zona Pellucida ◽  
Blastocyst Stage ◽  
Cell Stage ◽  
Development In Vitro ◽  
Single Blastomeres ◽  
Mammalian Eggs ◽  
Mouse Eggs

Up to the present time the function and significance of the zona pellucida in the development of mammalian eggs has not been fully explained. Zona-free mouse eggs will develop in vitro from the 2-cell stage, or later, up to the blastocyst stage (Tarkowski, 1961; Mintz, 1962; Gwatkin, 1963). Single blastomeres isolated at the 2-cell (Mulnard, 1965), 4- and 8-cell stage (Tarkowski & Wróblewska, 1967) will also develop in vitro up to the blastocyst stage. Similar experiments on development in vitro of 1- and 2-cell rabbit eggs (Edwards, 1964) showed that in this species also cleavage can occur when the zona pellucida is absent, although the blastomeres exhibit a tendency to fall away from each other. Tarkowski's observations (unpublished) would appear to show, however, that naked 1-, 2- and 4-cell mouse eggs do not develop when transferred to the oviduct. A few hours after transplanting the naked eggs none could be recovered by flushing the oviduct, whereas eggs surrounded by zonae which were transplanted simultaneously were recovered.

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