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The Relative Concentration of Solids in the Nucleolus, Nucleus, and Cytoplasm of the Developing Nerve Cell of the Chick

Growing and differentiating nerve cells of the fifth cranial ganglion of the chick embryo were studied by several means. During the period of 70 hours to 11 days of incubation (Hamburger-Hamilton stages 19 to 37) average cell mass increased more than 4.5 times while cells changed from relatively und...

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Detalles Bibliográficos
Autores principales: Merriam, R. W., Koch, William E.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1960
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2224863/
https://www.ncbi.nlm.nih.gov/pubmed/19866564
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author Merriam, R. W.
Koch, William E.
author_facet Merriam, R. W.
Koch, William E.
author_sort Merriam, R. W.
collection PubMed
description Growing and differentiating nerve cells of the fifth cranial ganglion of the chick embryo were studied by several means. During the period of 70 hours to 11 days of incubation (Hamburger-Hamilton stages 19 to 37) average cell mass increased more than 4.5 times while cells changed from relatively undifferentiated neuroblasts to morphologically characteristic nerve cells with long processes. By making simplifying assumptions about thickness of nucleus and nucleolus, relative to cytoplasmic thickness, it was possible to calculate solute concentration of nucleus and nucleolus relative to that of the cytoplasm from measurements of optical retardations through living cells. Differences in relative solute concentration were observed in nucleolus, cytoplasm, and nucleoplasm in the approximate ratio 1.2:1.0:0.8, respectively. The ratio remained essentially constant during the growth period examined despite the fact that the cell components grow at markedly different rates. This suggests that solid concentrations are physical characteristics of nucleus, nucleolus, and cytoplasm which are maintained even during rapid growth and differentiation. By cytochemical means it was demonstrated that mass increase in the nucleus is not associated with increase in deoxyribonucleic acid. Both ribonucleic acid and protein are in greater concentration in nucleolus and cytoplasm than in the nucleoplasm. Electron microscopy shows interruptions in the nuclear envelope as well as an approximately even distribution of electron density in nucleus and cytoplasm. It is pointed out that consistent differences in solid concentration can exist on either side of the nuclear envelope even though it contains "pores." Implications of these data are discussed.
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spelling pubmed-22248632008-05-01 The Relative Concentration of Solids in the Nucleolus, Nucleus, and Cytoplasm of the Developing Nerve Cell of the Chick Merriam, R. W. Koch, William E. J Biophys Biochem Cytol Article Growing and differentiating nerve cells of the fifth cranial ganglion of the chick embryo were studied by several means. During the period of 70 hours to 11 days of incubation (Hamburger-Hamilton stages 19 to 37) average cell mass increased more than 4.5 times while cells changed from relatively undifferentiated neuroblasts to morphologically characteristic nerve cells with long processes. By making simplifying assumptions about thickness of nucleus and nucleolus, relative to cytoplasmic thickness, it was possible to calculate solute concentration of nucleus and nucleolus relative to that of the cytoplasm from measurements of optical retardations through living cells. Differences in relative solute concentration were observed in nucleolus, cytoplasm, and nucleoplasm in the approximate ratio 1.2:1.0:0.8, respectively. The ratio remained essentially constant during the growth period examined despite the fact that the cell components grow at markedly different rates. This suggests that solid concentrations are physical characteristics of nucleus, nucleolus, and cytoplasm which are maintained even during rapid growth and differentiation. By cytochemical means it was demonstrated that mass increase in the nucleus is not associated with increase in deoxyribonucleic acid. Both ribonucleic acid and protein are in greater concentration in nucleolus and cytoplasm than in the nucleoplasm. Electron microscopy shows interruptions in the nuclear envelope as well as an approximately even distribution of electron density in nucleus and cytoplasm. It is pointed out that consistent differences in solid concentration can exist on either side of the nuclear envelope even though it contains "pores." Implications of these data are discussed. The Rockefeller University Press 1960-02-01 /pmc/articles/PMC2224863/ /pubmed/19866564 Text en Copyright © Copyright, 1960, by The Rockefeller Institute Press
spellingShingle Article
Merriam, R. W.
Koch, William E.
The Relative Concentration of Solids in the Nucleolus, Nucleus, and Cytoplasm of the Developing Nerve Cell of the Chick
title The Relative Concentration of Solids in the Nucleolus, Nucleus, and Cytoplasm of the Developing Nerve Cell of the Chick
title_full The Relative Concentration of Solids in the Nucleolus, Nucleus, and Cytoplasm of the Developing Nerve Cell of the Chick
title_fullStr The Relative Concentration of Solids in the Nucleolus, Nucleus, and Cytoplasm of the Developing Nerve Cell of the Chick
title_full_unstemmed The Relative Concentration of Solids in the Nucleolus, Nucleus, and Cytoplasm of the Developing Nerve Cell of the Chick
title_short The Relative Concentration of Solids in the Nucleolus, Nucleus, and Cytoplasm of the Developing Nerve Cell of the Chick
title_sort relative concentration of solids in the nucleolus, nucleus, and cytoplasm of the developing nerve cell of the chick
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2224863/
https://www.ncbi.nlm.nih.gov/pubmed/19866564
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