The Histones Associated With Condensed and Extended Chromatin of Mouse Liver

Johmann, Carol A.; Eckhardt, Ronald A.; Gorovsky, Martin A.

doi:10.1083/jcb.58.1.119

Cited by 20 publications

(5 citation statements)

References 35 publications

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“…Such studies have often shown differences in one or more histone fractions or subfractions, between different fractions of chromatin from the same nuclei, among diflerent tissues or developmental stages of an organism, or among different species (see e.g. Johmann et al, 1973;Elgin and Boyd, 1975;Oliver and Chalkley, 1972b). The present study indicates differences in histone composition between chromatin from different developmental stages as well as between chromatin from different species of Drosophila.…”

Section: Discussionsupporting

confidence: 56%

“…Under certain conditions of preparation, Krause et al (1974) found an enrichment of H3 in the nuclei of stationary cultured mouse L-cells and an enrichment of H4 in the nuclei of exponentially growing cells. After fractionation of the chromatin from mouse and rat liver, the extended fraction, which is active in RNA synthesis, was shown to have a conspicuous reduction in the relative amount of H4 as compared to the inactive, condensed fraction (Johmann et al, 1973;Gottesfeld et al, 1974).…”

Section: Discussionmentioning

confidence: 99%

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Histone content in relation to amount of heterochromatin and developmental stage in three species of Drosophila

et al. 1976

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Relative amounts of various histone fractions in Drosophila chromatin were estimated densitometrically on electrophoretic gel separations. Several consistent and highly significant differences were obtained between larval and adult chromatin. The arginine-rich histones showed the most conspicuous changes: higher amounts of H4 in larvae, higher H3 in adults. The level of modification of these histones was clearly higher in larval than in adult chromatin. The modification of the two slower subfractions of H4 involved, in all probability, phosphorylation as well as acetylation. In all types of Drosophila chromatin studied 50% or more of the H2a molecules were phosphorylated--a remarkably high proportion. The species differences observed in relative amounts of histone were consistent in both stages of development. D. melanogaster differed from D. hydei and D. virilis in all histones except H2b, while the latter two species were generally similar. The interspecific variation in histone pattern was generally not correlated to differences in content of heterochromatin. The level of modification of H2 was, however, presumably an exception, as it was significantly lower for both larvae and adults in D. virilis than in the other two species. These differ from D. virilis in containing appreciably lower proportions of heterochromatic chromosome segments.

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Section: Discussionsupporting

confidence: 56%

Section: Discussionmentioning

confidence: 99%

Histone content in relation to amount of heterochromatin and developmental stage in three species of Drosophila

et al. 1976

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“…However, until these studies are repeated using more sensitive methods, it is not possible to determine whether these other organisms show differences between sperm and somatic histones which are as small as (or smaller than) those reported here. matin condensation or in the control of genetic activity are still obscure (13,16).…”

Section: Frog Testis Histonesmentioning

confidence: 99%

“…This is rather surprising since histone F3s of different organisms have the same mobitities on urea-polyacrylamide gels at low pH (26) and the amino acid sequences of F3s from diverse sources are remarkably similar (4,8,15). Since histones show anomalous behavior on SDS-containing polyacrylamide gels (25,14,16), the molecular basis for this difference between calf and frog F3 is not clear.…”

Section: Frog Liver Histonesmentioning

confidence: 99%

Electrophoretic analysis of liver and testis histones of the frog Rana pipiens.

Alder¹,

Gorovsky²

1975

The Journal of Cell Biology

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Histones were extracted from frog livers and testes and analyzed by electrophoresis on long polyacrylamide gels and on sodium dodecyl sulfate (SDS)-containing polyacrylamide gels. Frog histones were found to be similar to those of calf thymus except that frog histone fraction F2A2 showed a marked dependence on the temperature at which the long gels were run, and frog histone fraction F3 could be separated from frog F2B on SDS-containing gels.Comparisons between frog liver and frog testis histones indicated that the testis contains as its major F1 component a fast migrating species not found in liver. Testis histones also showed less microheterogeneity of fractions F3 and F2A 1 than liver histones. These were the only differences observed between liver and testis histones, even when testis histones were prepared from sperm suspensions that were rich in cells in the late stages of spermiogenesis. Thus it seems that, in Rana, the electrophoretic properties of the basic proteins of sperm differ from those of somatic cells only in the nature of histone FI and in the degree of microheterogeneity of fractions F2AI and F3.The sperm cells of most organisms contain highly condensed chromatin and are genetically inactive. In many species, sperm also contain basic proteins which differ from the histones associated with the chromatin of somatic cells (3,9,10,18,29). It is tempting to suggest that at least some of the differences between the basic proteins of sperm and somatic cells are somehow correlated with either the genetic inactivity or with the presence of highly condensed chromatin in sperm. However, there are organisms in which spermiogenesis is reported not to involve detectable changes in histories. For example, in the frog Rana pipiens, the sperm have been shown to contain somatic type histones both cytochemically (33) and biochemically (2, 30, 31). However, recent advances in methods for isolating and characterizing histones (22, 23) have led us to reexamine the histones of R.pipiens spermiogenic cells to determine if, in fact, there are no differences between sperm and somatic histones. MATERIALS AND METHODS Preparation of TissuesSexually mature male R. pipiens were obtained from Vermont Frog Farms (Albury, Vt.) and were either used as shipped or treated with tetracycline-HCl (5 mg/0.2 ml of water twice per week) following the method of Gibbs et al. (I 1).For use, frogs were struck on the head, pithed, and then dissected on ice. Livers were removed and cold 0.9% NaCI-0.01 M Na-oxalate was forced through the tissue by injection with a 22-gauge needle to remove residual blood cells. Livers were used immediately for nucleus isolations or were quick-frozen on dry ice and stored at -20~ This process usually took 4-5 min.Testes were dissected and were either quick-frozen immediately or macerated into llYTo Holtfreter's solution

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“…Nevertheless, nucleohistones may eventually be involved not only in the maintenance of the conformation of chromatin but also in the control of the activity of genome. [12][13][14][15][16] Zinc has been reported to be the cofactor of many enzymes. 7 8 Little is known about its effect on nuclear enzymes.…”

mentioning

confidence: 99%