The production of tissue-specific histone complements during development

1988 ◽  
Vol 66 (6) ◽  
pp. 636-649 ◽  
Author(s):  
Ronald W. Lennox ◽  
Leonard H. Cohen
Keyword(s):  
Sea Urchin ◽  
Cultured Cells ◽  
Intact Animal ◽  
Biological Significance ◽  
Tissue Specific ◽  
Major Mechanism ◽  
Mammalian Tissues ◽  
Dividing Cells ◽  
Tissue Differences

At least two mechanisms generate tissue differences in the histone subtype composition during development: subtype dilution and subtype replacement. Subtype dilution, which occurs when cells continue dividing after having ceased to synthesize one or more histone subtypes, allows the elimination of stable subtypes. It is the major mechanism generating cell differences in histone composition in sea urchin embryogenesis. Subtype replacement has been observed in mammalian tissues, both in the intact animal and in cultured cells. It is most evident in nondividing cells but occurs to some extent in dividing cells as well. Examples of the two mechanisms are presented and their possible biological significance, as well as that of the differences they produce, is discussed.

Nicotinic acid–adenine dinucleotide phosphate (NAADP) elicits specific microsomal Ca2+ release from mammalian cells

2001 ◽  
Vol 353 (3) ◽  
pp. 531-536 ◽  
Author(s):  
Ahad N.-K. YUSUFI ◽  
Jingfei CHENG ◽  
Michael A. THOMPSON ◽  
Eduardo N. CHINI ◽  
Joseph P. GRANDE
Keyword(s):  
Nicotinic Acid ◽  
Intracellular Calcium ◽  
Sea Urchin ◽  
Mammalian Cells ◽  
Calcium Release ◽  
Cultured Cells ◽  
Mesangial Cells ◽  
Rat Kidney ◽  
Leukaemia Cell Line ◽  
Mammalian Tissues

Nicotinic acid–adenine dinucleotide phosphate (NAADP), a molecule derived from β-NADP, has been shown to promote intracellular calcium release in sea urchin eggs. However, there is little information regarding the role of NAADP in the regulation of intracellular calcium fluxes in mammalian cells. We found recently that several mammalian tissues have a high capacity for NAADP synthesis, as assessed by sea urchin egg bioassay. To determine the functional significance of NAADP production by mammalian tissues, we sought to determine whether NAADP is capable of inducing calcium release from microsomes prepared from cultured cells. We found that NAADP, but not β-NADP, activates a specific microsomal calcium release system in mesangial cells isolated from rat kidney; NAADP was without effect in renal tubular epithelial cells. NAADP-induced calcium release is not affected by inhibitors of the inositol 1,4,5-trisphosphate or ryanodine channels. However, NAADP-elicited calcium release was inhibited by L-type calcium channel blockers and by alkaline phosphatase treatment of NAADP. NAADP also promotes specific microsomal calcium release in rat vascular smooth muscle cells, cardiac myocytes, fibroblasts and a human leukaemia cell line, indicating that the capacity for NAADP-induced calcium release is widespread in mammalian cells. We propose that NAADP may be an important regulator of intracellular calcium in many mammalian tissues.

Surface Characters of Dividing Cells

1958 ◽  
Vol 35 (2) ◽  
pp. 396-399
Author(s):  
SHOZO ISHIZAKA
Keyword(s):  
Sea Urchin ◽  
Optical Section ◽  
Camera Lucida ◽  
Centre Of Gravity ◽  
Whole Process ◽  
Spindle Axis ◽  
Sea Urchin Egg ◽  
Dividing Cells

1. The surface movements during division have been studied by marking the naked surface of the sea-urchin egg with charcoal particles. 2. The contours of the largest optical section, the positions of the particles thereon and the positions of the astral centres are recorded in a series of camera lucida drawings. 3. The drawings are then superimposed, the centre of gravity and spindle axis being used for reference. 4. It is thereby shown that there are two surface rings which remain in the same positions throughout the whole process of division. 5. It is concluded that these rings indicate regions where stresses remain balanced during division.

scholarly journals MITO-Tag Mice enable rapid isolation and multimodal profiling of mitochondria from specific cell types in vivo

2018 ◽  
Vol 116 (1) ◽  
pp. 303-312 ◽  
Author(s):  
Erol C. Bayraktar ◽  
Lou Baudrier ◽  
Ceren Özerdem ◽  
Caroline A. Lewis ◽  
Sze Ham Chan ◽  
...  
Keyword(s):  
Metabolite Profiling ◽  
Cultured Cells ◽  
Transgenic Animals ◽  
Cell Types ◽  
Tissue Level ◽  
Specific Cell ◽  
Mammalian Tissues ◽  
Cell Type Specific ◽  
Untargeted Metabolite Profiling

Mitochondria are metabolic organelles that are essential for mammalian life, but the dynamics of mitochondrial metabolism within mammalian tissues in vivo remains incompletely understood. While whole-tissue metabolite profiling has been useful for studying metabolism in vivo, such an approach lacks resolution at the cellular and subcellular level. In vivo methods for interrogating organellar metabolites in specific cell types within mammalian tissues have been limited. To address this, we built on prior work in which we exploited a mitochondrially localized 3XHA epitope tag (MITO-Tag) for the fast isolation of mitochondria from cultured cells to generate MITO-Tag Mice. Affording spatiotemporal control over MITO-Tag expression, these transgenic animals enable the rapid, cell-type-specific immunoisolation of mitochondria from tissues, which we verified using a combination of proteomic and metabolomic approaches. Using MITO-Tag Mice and targeted and untargeted metabolite profiling, we identified changes during fasted and refed conditions in a diverse array of mitochondrial metabolites in hepatocytes and found metabolites that behaved differently at the mitochondrial versus whole-tissue level. MITO-Tag Mice should have utility for studying mitochondrial physiology, and our strategy should be generally applicable for studying other mammalian organelles in specific cell types in vivo.

scholarly journals MITO-Tag Mice enable rapid isolation and multimodal profiling of mitochondria from specific cell types in vivo

2018 ◽  
Author(s):  
Erol Can Bayraktar ◽  
Lou Baudrier ◽  
Ceren Özerdem ◽  
Caroline A. Lewis ◽  
Sze Ham Chan ◽  
...  
Keyword(s):  
Metabolite Profiling ◽  
Cultured Cells ◽  
Transgenic Animals ◽  
Cell Types ◽  
Tissue Level ◽  
Specific Cell ◽  
Mammalian Tissues ◽  
Cell Type Specific ◽  
Untargeted Metabolite Profiling

ABSTRACTMitochondria are metabolic organelles that are essential for mammalian life, but the dynamics of mitochondrial metabolism within mammalian tissues in vivo remains incompletely understood. While whole-tissue metabolite profiling has been useful for studying metabolism in vivo, such an approach lacks resolution at the cellular and subcellular level. In vivo methods for interrogating organellar metabolites in specific cell-types within mammalian tissues have been limited. To address this, we built on prior work in which we exploited a mitochondrially-localized 3XHA epitope-tag (“MITO-Tag”) for the fast isolation of mitochondria from cultured cells to now generate “MITO-Tag Mice.” Affording spatiotemporal control over MITO-Tag expression, these transgenic animals enable the rapid, cell-type-specific immunoisolation of mitochondria from tissues, which we verified using a combination of proteomic and metabolomic approaches. Using MITO-Tag Mice and targeted and untargeted metabolite profiling, we identified changes during fasted and refed conditions in a diverse array of mitochondrial metabolites in hepatocytes and found metabolites that behaved differently at the mitochondrial versus whole-tissue level. MITO-Tag Mice should have utility for studying mitochondrial physiology and our strategy should be generally applicable for studying other mammalian organelles in specific cell-types in vivo.

Surface Characters of Dividing Cells

1966 ◽  
Vol 44 (2) ◽  
pp. 225-232
Author(s):  
SHOZO ISHIZAKA
Keyword(s):  
Sea Urchin ◽  
Surface Stress ◽  
Radius Of Curvature ◽  
Surface Movement ◽  
Daughter Cells ◽  
Sea Urchin Egg ◽  
Area Increase ◽  
Dividing Cells ◽  
Division Process ◽  
Surface Area Increase

1. Surface movement of the dividing spermatocyte of the grasshopper, Acrida lata, was followed by a marking method. 2. Throughout the division process of the spermatocytes, incipient daughter cells maintain spherical contours. 3. By direct observation of markers and calculation using the condition given in item 2, the following points are established. (a) As in the sea-urchin egg, there are a pair of circular zones on a grasshopper spermatocyte surface which retain their respective radii unchanged while the cell undergoes a division. (b) In the grasshopper spermatocyte, unlike the sea-urchin egg, the surfaces of these circular zones do change their positions and move towards the poles during division. (c) As a spherical cell goes through a constricted form to become two daughter cells, not only is the radius of curvature of the surface everywhere uniform (item 2), but both axial length and surface area increase uniformly everywhere except in the region of the furrow. 4. From the findings of item 3 it is inferred that the prevailing surface stress is uniform and isotropic, like surface tension, and that the force causing division must be derived from some other parts of the cell such as the furrow cortex or the endoplasm. 5. Basically, the nature of the surface of sea-urchin eggs is similar to that of the spermatocyte. That the circular zones of the former are stationary while those of the latter move steadily during cleavage is tentatively explained in terms of the speed of advance of the furrow in relation to the relaxation time of the cortex.

scholarly journals Didecanoyl phosphatidylcholine is a superior substrate for assaying mammalian phospholipase D

1996 ◽  
Vol 319 (3) ◽  
pp. 861-864 ◽  
Author(s):  
Anne M VINGGAARD ◽  
Torben JENSEN ◽  
Clive P. MORGAN ◽  
Shamshad COCKCROFT ◽  
Harald S. HANSEN
Keyword(s):  
Detection Limit ◽  
Phospholipase D ◽  
Cultured Cells ◽  
Human Neutrophils ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Mammalian Tissues ◽  
Radioactive Concentration ◽  
Adp Ribosylation Factor ◽  
Cytosolic Factor ◽  
Assay Conditions

Phospholipase D (PLD) activity in crude or solubilized membranes from mammalian tissues is difficult to detect with the current assay techniques, unless a high radioactive concentration of substrate and/or long incubation times are employed. Generally, the enzyme has to be extracted and partially purified on one column before easy detection of activity. Furthermore, PLD activity in cultured cells can only be detected by the available assay techniques in the presence of guanosine 5´-[γ-thio]triphosphate (GTP[S]) and a cytosolic factor [usually ADP-ribosylation factor (Arf)]. In this paper we report that the use of didecanoyl phosphatidylcholine (C10-PC) in mammalian PLD assays considerably increases the detection limit. C10-PC was compared with the commonly used dipalmitoyl phosphatidylcholine (C16-PC) as a substrate for PLD activity from membranes of human neutrophils, human placenta and pig brain, and from placental cytosol. C10-PC was superior to C16-PC by a factor of 2–28 depending on assay conditions and tissue, and it allowed the detection of GTP[S]-and Arf-stimulated PLD activity without addition of phosphatidylinositol 4,5-bisphosphate.

scholarly journals Conservation of ribosomal RNA during compensatory renal hypertrophy. A major mechanism in RNA accretion.

1976 ◽  
Vol 69 (3) ◽  
pp. 548-556 ◽  
Author(s):  
W T Melvin ◽  
A Kumar ◽  
R A Malt
Keyword(s):  
Ribosomal Rna ◽  
Cultured Cells ◽  
Compensatory Hypertrophy ◽  
Mouse Kidney ◽  
Average Increase ◽  
Renal Hypertrophy ◽  
Major Mechanism ◽  
Compensatory Renal Hypertrophy

After removal of one mouse kidney, compensatory hypertrophy in the remaining kidney is marked in 2 days by a 20% average increase in ribosomal RNA (rRNA) per cell. Both 28S and 18S RNA are conserved during the initial stages of compensatory renal hypertrophy to an extent sufficient to account for the rest of the observed accumulation of rRNA. Like some cultured cells, the kidney conserves rRNA during physiological growth.

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