Abstract
The microchromosomes of Japanese quail fibroblasts are shown to be heterochromatic and nucleolus-organizing. Autoradiographic studies indicate that although some DNA replication takes place early, the time of intense replication is in the late S period after most replication in the macrochromosomes has ceased. Analytical centrifugation of quail DNA demonstrated a main band with a buoyant density of 1.701 g/cm3 and a satellite constituting about 5% of the DNA with a buoyant density of 1.715. The G-C content of the main and satellite band was 42 and 55 percent respecively by both buoyant density and DNA Tm. The satellite band renatured much more rapidly than main band DNA indicating it was composed of highly repetitive sequences. When purified satellite DNA was centrifuged at pH 13 it separated into three portions, a major central band constituting 72% of the satellite DNA, and two smaller bands, one heavier and one lighter than the central band, each constituting 14% of the satellite DNA. This indicated that in a portion of the satellite DNA the bases were non-randomly distributed in the half-DNA helices.
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Bianchi, N. O., Molina, O. J.: Chronology and pattern of replication in the bone marrow chromosomes of Gallus domesticus. Chromosoma (Berl.) 21, 387–397 (1967).
Birnstiel, M., Speirs, J., Purdom, I., Jones, K., Loening, U. E.: Properties and composition of the isolated ribosomal DNA satellite of Xenopus laevis. Nature (Lond.) 219, 454–463 (1968).
Britten, R. J., Kohne, D. E.: Repeated sequences in DNA. Science 161, 529–540 (1968).
Brown, D. D., Dawid, I. B.: Specific gene amplification in oocytes. Science 160, 272–280 (1968).
Clement, W. M.: Autoradiographic studies of the chromosomes of the domestic fowl. Genetics 61, 11s (1969).
Comings, D. E.: Quantitative autoradiography of heterochromatin replication in Microtus agrestis. Chromosoma 29, 434–445 (1970).
Doerfler, W., Hogness, D. S.: Separation of the strands of poly d-TG: AC in alkaline CsCl. J. molec. Biol. 14, 237–240 (1965).
Donnelly, G. M., Newcomer, E. H.: Autoradiographic patterns in cultured leukocytes of the domestic fowl. Exp. Cell Res. 30, 363–368 (1963).
Flamm, W. G., Bond, H. E., Burr, H. E.: Density-gradient centrifugation of DNA in a fixed-angle rotor. Biochim. biophys. Acta (Amst.) 129, 310–319 (1966).
— McCallum, M., Walker, P. M. B.: The isolation of complementary strands from a mouse DNA fraction. Proc. nat. Acad. Sci. (Wash.) 57, 1729–1734 (1967).
— Walker, P. M. B., McCallum, M.: Some properties of the single strands isolated from the DNA of the nuclear satellites of the mouse (Mus musculus). J. molec. Biol. 40, 423–443 (1969a).
—: Renaturation and isolation of single strands from nuclear DNA of the guinea pig. J. molec. Biol. 42, 441–455 (1969b).
Gall, J. G., Pardue, M. L.: Formation and detection of RNA-DNA hybrid molecules in cytological preparations. Proc. nat. Acad. Sci. (Wash.) 63, 378–383 (1969).
Lima-de-Faria, A., Birnstiel, M., Jaworska, H.: Amplification of ribosomal cistrons in the heterochromatin of Acheta. Genetics 61 (Suppl.) 145–159 (1969).
Mandel, M., Marmur, J.: Use of ultraviolet absorbance-temperature profile for determining guanine plus cytosine content of DNA. Methods in Enzymology 12B, 195–206 (1968).
— Schildkraut, C. L., Marmur, J.: Use of CsCI density gradient analysis for determining the guanine plus cytosine content of DNA. Methods in Enzymology 12B, 184–195 (1968).
Matsuda, K., Siegel, A.: Hybridization of plant ribosomal RNA to DNA: The isolation of a DNA component rich in ribosomal RNA cistrons. Proc. nat. Acad. Sci. (Wash.) 58, 673–680 (1967).
Newcomer, E. H.: The mitotic chromosomes of the domestic fowl. J. Hered. 48, 227–234 (1957).
Ohno, S.: Sex chromosomes and microchromosomes of Gallus domesticus. Chromosoma (Berl.) 11, 484–498 (1961).
— Christian, L. C., Stenius, C.: Nucleolus-organizing microchromosomes of Gallus domesticus. Exp. Cell Res. 27, 612–614 (1962).
Schmid, W.: DNA replication patterns of the heterochromosomes in Gallus domesticus. Cytogenetics 1, 344–352 (1962).
Skinner, D. M.: Deoxyribonucleic acid sequences complementary to ribosomal ribonucleic acid in a crustacean. Biochemistry 8, 1467–1473 (1969).
Stafford, D. R., Guild, W. R.: Satellite DNA from sea urchin sperm. Exp. Cell Res. 55, 347–350 (1969).
Szybalski, W.: Use of cesium sulfate for equilibrium density gradient centrifugation. Methods in Enzymology 12B, 330–360 (1968).
Waring, M., Britten, R. J.: Nucleotide sequence repetition: A rapidly reassociating fraction of mouse DNA. Science 154, 791–794 (1966).
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Supported by N.I.H. Grant GM-15886, The Charles and Henrietta Detoy Research Fellowship.
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Comings, D.E., Mattoccia, E. Studies of microchromosomes and a G-C rich DNA satellite in the quail. Chromosoma 30, 202–214 (1970). https://doi.org/10.1007/BF00282001
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DOI: https://doi.org/10.1007/BF00282001