Summary
DNA synthesis and mitosis were initiated in cultured tobacco pith tissue by means of IAA and kinetin. DNA classes were determined by microspectrophotometric measurements (Feulgen); autoradiographs (tritiated thymidine) served to ascertain whether or not nuclei had undergone DNA synthesis during culture.
All mitoses in “new” cells (resulting from divisions in culture) were diploid and had been preceded by DNA synthesis in culture.
Whereas many of the “old” cells (which had not previously divided in culture) found in diploid or polyploid mitosis had undergone DNA synthesis during culture, others had not. Such non-radioactive mitoses still occurred after 16 days.
In view of this, a 4 C nucleus in differentiated tissue should be considered as potentially both diploid and tetraploid, for it appears impossible to predict whether it would, upon restoration of conditions conducive to DNA synthesis and mitosis, enter a diploid mitosis or, after undergoing DNA synthesis, a tetraploid one.
A high nuclear DNA content seems to have a much more inhibiting effect on the onset of DNA doubling than on that of mitosis.
Somatic polyploidization is understood as the result of two DNA doublings between which mitosis was omitted, or aborted, or in effect undone by a failure of cytokinesis leading to fusion during a later mitosis.
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Literature
Berger, C. A.: Multiplication and reduction of somatic chromosome groups as a regular developmental process in the. mosquito, Culex pipiens. Publ. 496 Carnegie Inst. Wash., 209–232 (1938).
D'Amato, F.: A brief discussion on “endomitosis”. Caryologia (Firenze) 6, 341–345 (1954).
Das, N. K., K. Patau and F. Skoog: Initiation of mitosis and cell division by kinetin and indole-acetic acid in excised tobacco pith tissue. Physiol. Plantarum (Cph.) 9, 640–651 (1956).
—: Autoradiographic and microspectrophotometric studies of DNA synthesis in excised tobacco pith tissue. Chromosoma (Berl.) 9, 606–617 (1958).
Ficq, A., and C. Pavan: Autoradiography of polytene chromosomes of Rhynchosciara angelae at different stages of larval development. Nature (Lond.) 180, 983–984 (1957).
Firket, H.: Recherches sur la synthèse des acides désoxyribonucléiques et la préparation a la mitose dans des cellules cultivées “in vitro”. (Etude cytophotométrique et autoradiographique.) Arch. Biol. (Liège) 69, 1–166 (1957).
Geitler, L.: Die Entstehung der polyploiden Somakerne der Heteropteren durch Chromosomenteilung ohne Kernteilung. Chromosoma (Berl.) 1, 1–22 (1939).
— Endomitose und endomitotische Polyploidisierung. Protoplasmatologia 6c, 1–89 (1953).
Grell, M.: Cytological studies in Culex. I. Somatic reduction divisions. Genetics 31, 60–76 (1946).
Huskins, C. L., and L. M. Steinitz: The nucleus in differentiation and development. II. Induced mitoses in differentiated tissues of Rhoeo roots. J. Hered. 39, 67–77 (1948).
Jardetzky, C. D., C. P. Barnum and H. Vermund: Deoxyribonucleic acid and phospholipide metabolism in regenerating liver and the effect of X-radiation. J. biol. Chem. 222, 421–433 (1956).
Levan, A.: Cytological phenomena connected with the root swelling by growth substances. Hereditas (Lund) 25, 87–96 (1939).
Lima-de-Faria, A.: Differential uptake of tritiated thymidine into hetero and euchromatin in Melanoplus and Secale. J. biophys. biochem. Cytol. 6, 457–466 (1959).
Naylor, J. M.: Control of nuclear processes by auxin in axillary buds of Tradescantia paludosa. Canad. J. Bot. 36, 221–232 (1958).
Patau, K.: The DNA content of nuclei in root tips of Rhoeo discolor. Rec. Gen. Soc. Amer. 21, 56 (1952).
—, N. K. Das and F. Skoog: Induction of DNA synthesis by kinetin and indoleacetic acid in excised tobacco pith tissue. Physiol. Plantarum (Cph.) 10, 949–966 (1957).
—, and H. Swift: The DNA-content (Feulgen) of nuclei during mitosis in a root tip of onion. Chromosoma (Berl.) 6, 149–169 (1953).
Pavan, C.: Morphological and physiological aspects of chromosomal activities. Proc. 10th Internat. Congr. Genetics 1, 321–336 (1959).
Price, J. M., and A. K. Laird: A comparison of the intracellular composition of regenerating liver and induced liver tumors. Cancer Res. 10, 650–658 (1950).
Rudkin, G. T., and S. L. Corlette: Disproportionate synthesis of DNA in a polytene chromosome region. Proc. Nat. Acad. Sci. (Wash.) 43, 964–968 (1957).
Srinivasachar, D.: The DNA-content of nuclei in the meristem of onion roots. Ph. D. Thesis, Univ. of Wisconsin 1953.
Stich, H. F., and J. M. Naylor: Variation of desoxyribonucleic acid content of specific chromosome regions. Exp. Cell Res. 14, 442–445 (1958).
Taylor, J. H.: Asynchronous duplication of chromosomes in cultured cells of Chinese hamster. J. biophys. biochem. Cytol. 7, 455–464 (1960).
Tschermak-Woess, E.: Karyologische Pflanzenanatomie. Protoplasma (Wien) 46, 789–834 (1956).
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This work has been supported by research grants to K. Patau from the U.S. Public Health Service (grant No. C-3313) and the American Cancer Society.
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Patau, K., Das, N.K. The relation of DNA synthesis and mitosis in tobacco pith tissue cultured in vitro. Chromosoma 11, 553–572 (1960). https://doi.org/10.1007/BF00328674
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DOI: https://doi.org/10.1007/BF00328674