ATP level and cleavage of sea urchin eggs (O. F. M�ller)

Zotin, A. I.; Mil'man, L S; Faustov, V.S.

doi:10.1016/0014-4827(65)90058-3

Cited by 26 publications

(3 citation statements)

References 17 publications

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“…FUDR is well known as a selective inhibitor of DNA synthesis in plants and other organisms; its action depends upon causing thymidylic acid deficiency by blocking thymidylate synthetase (5, 27). The specificity of FUDR action on the tobacco pith explants is substantiated by the prevention of FUDR effect with thymidine and not uridine, nevertheless its effect on DNA synthesis may lead to an inhibition of RNA synthesis (5,13,37) and even synthesis of some enzymes (13,32).…”

Section: Discussionmentioning

confidence: 99%

A Requirement for DNA Synthesis during Auxin Induction of Cell Enlargement in Tobacco Pith Tissue

Maheshwari

Noodén

1971

Physiologia Plantarum

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IAA (indoleacetic acid) is known to induce cell enlargement without cell division in tobacco pith explants grown on an agar medium without added cytokinin. The very long lag period before IAA (2 × 10−5M) stimulates growth, about 3 days, can be useful to study the metabolic changes which lead to the promotion of growth. When the disks are transferred to a medium without IAA after 2 days or less of treatment with IAA, the IAA does not stimulate growth. Disks transferred after 3 days, subsequently show an auxin response, almost as great as those given IAA continuously. At 5 × 10−4M, 5‐fluorodeoxyuridine (FUDR), which inhibits DNA synthesis by blocking formation of thymidylate, completely suppresses the lAA‐induced growth if it is added together with the IAA or 1 day later. When the FUDR is given 2 days after the IAA, there is a small increment of auxin‐induced growth, and an even greater amount if added after 3 days. The period when exogenous auxin must be present to stimulate growth corresponds to the period of FUDR sensitivity. The FUDR inhibition is prevented by thymidine but not by uridine. Other inhibitors of DNA synthesis, hydroxyurea and fluorouracil, also inhibit auxin‐induced growth. Thus DNA synthesis seems to be required for auxin induction of cell enlargement in tobacco pith explants. In contrast, FUDR does not inhibit auxin‐induced growth in corn coleoptile and artichoke tuber sections.

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Section: Discussionmentioning

confidence: 99%

A Requirement for DNA Synthesis during Auxin Induction of Cell Enlargement in Tobacco Pith Tissue

Maheshwari

Noodén

1971

Physiologia Plantarum

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“…First, they do not directly inhibit polymerization of microtubules from brain (see below) and thus must act indirectly on microtubules. In the case of DNP, an uncoupler of oxidation phosphorylation in eggs (38) as well as other tissues, ATP levels in eggs have been shown to decrease (39) and the effect could involve ATP or potentially some other product of mitochondrial metabolism such as calcium (40) or hydrogen ion. With methyl xanthines the effect is unlikely t o be through the mitochondrial system as we shall now discuss.…”

Section: Dispersing Effects Of Colchicine Dinitrophenol (Dnp) and Mmentioning

confidence: 99%

Regulation of size and birefringence of the in vivo mitotic apparatus

et al. 1974

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Long chain glycols augment in size and birefringence the in vivo mitotic apparatus (MA) oE marine eggs. Dinitrophenol and caffeine antagonize the effect but they can be balanced by glycols. Caffeine inhibits the phosphodiesterase for cyclic AMP (CAMP) and CAMP levels increase in its presence. However, added dlbutyryl CAMP does not affect MAS o r cleavage, but is taken up by eggs. Oxygen uptake studies show that caffeine depresses oxidative metabolism but does not affect ATP levels. Action through the pentosephosphate shunt is suggested.Glycols influence the assembly of tubulin. Optical ultracentrifuge patterns of tubulin polymerized without glycol show a 6s and 30s peak. Similar patterns of tubulin polymerized at pH 6.4 in glycol and depolymerized in its absence show 6S, 8-18S, and 30S, peaks. The 8-18s peak appears in equilibrium with the 6s peak. If glycol is added t o cold tubulin polymerized without glycol, only 6s and 30s peaks occur. Preparations with no 30s peak d o not show 450 A rings in the EM.Calcium depolymerizes microtubules. In the absence of glycols 450 a rings are seen.In the presence of glycol, much higher concentrations of calcium are necessary for depolymerization, and few 450 8, rings occur.We suggest that glycols prevent formation of the stable 30s peak, favor an intermediate structure in equilibrium with the 6s peak, and antagonize calcium depolymerization. Their in vivo effects may arise from these interactions.

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“…In addition to the synthesis of DNA and ATP, the first cleavage of echinoderm eggs appears to require protein synthesis (Hultin, 1961 ;Zotin, Milman and Faustov, 1965;Young, Hendler and Karnofsky, 1969). In order to further elucidate the mechanisms of ME action on cleavage, it is necessary to obtain more detailed information on the response of cells to ME during the cleavage cycles and on the relationship between protein synthesis required for division and the effects of ME.…”

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confidence: 99%

Delay and Quadripartition in Sea Urchin Eggs Induced by Short Exposure to 2-Mercaptoethanol

Yuyama¹

1971

The Biological Bulletin

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ATP level and cleavage of sea urchin eggs (O. F. M�ller)

Cited by 26 publications

References 17 publications

A Requirement for DNA Synthesis during Auxin Induction of Cell Enlargement in Tobacco Pith Tissue

A Requirement for DNA Synthesis during Auxin Induction of Cell Enlargement in Tobacco Pith Tissue

Regulation of size and birefringence of the in vivo mitotic apparatus

Delay and Quadripartition in Sea Urchin Eggs Induced by Short Exposure to 2-Mercaptoethanol

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