Full text in pdf format

Mg²⁺-dependent ATPase activity investigated in heterochromatin, euchromatin and nucleoli of Triatoma infestans

M.T.V. Azeredo-Oliveira^I; M.L.S. Mello^II

^IDepartamento de Biologia, IBILCE, UNESP, 15100 São José do Rio Preto, SP, Brasil
^IIDepartamento de Biologia Celular, IB, UNICAMP, 13100 Campinas, SP, Brasil. Send correspondence to M.L.S.M.

ABSTRACT

Mg^t+-dependent ATPases were demonstrated with cytoenzymological procedures at the light microscope level in euchromatin and nucleoli, but not in the heterochromatin of polyploid nuclei of T. infestans nymphae during development. At the electron microscope level, euchromatin did not exhibit the reaction product, a finding which is attributed to slight differences in the methodology as compared with that for light microscopy. The ATPases detected in euchromatin are assumed to be related to its transcriptional activities

Keywords: Mg²⁺; ATPase; heterochromatin; Triatoma infestans.

REFERENCES

Agutter, P.S., McArdle, H.J. and McCaldin, B. (1976). Evidence for involvement of nuclear envelope nucleoside triphosphate in nucleocytoplasmic translocation of ribonucleoprotein. Nature, 263: 165-167.

Agutter, P.S., Harris, J.R. and Stevenson, I. (1977). Ribonucleic acid stimulation of mammalian liver nuclear-envelope nucleoside triphosphatase. Biochem. J. 162: 671-679.

Alberts, B. and Sternglanz, R. (1977). Recent excitement in the DNA replication problem. Nature 9: 955-961.

Arai, -K-I., Low, R.L. and Kornberg, A. (1981). Movement and site selection for priming by the primosome in phage tX174 DNA replication. Proc. Natl. Acad. Sci. USA 78: 707-711.

Buchavalov, I.B. and Unger, E. (1977). Enzyme activity of nuclear ribonucleoproteins. Exp. Cell Res. 106: 139-150.

Fox, N., Fernandez, C. and Studzinski, G.P. (1981). Visualization of nucleolar substructure in cultured human fibroblasts by magnesium-activated adenosine triphosphatase reaction. J. Histochem. Cytochem. 29: 1115-1120.

Karsenti, G. and Gounon, P. (1979). Lampbrush chromosomes: Are they ATP dependent contractile structures? Biol. Cell. 34: 91-98.

Lehninger, A.L. (1976). Bioquímica. Edgard Blucher, São Paulo.

Mello, M.L.S. (1971). Nuclear behavior in the Malpighian tubes of Triatoma infestans (Rcduv., Hemiptera). Cytologia 36:42-49.

Pautrat, G. and Benkoel, L. (1977). Adenosine triphosphatase activity during fusion of culture sheep choroid plexus cells induced by either Visna virus or polyethylene glycol. Cell. Mol. Biol. 23: 349-354.

Racker, L. (1976). A New Look at Mechanisms in Bioenergetics. Academic Press, New York. Rubin, A.H. and Chu, B. (1978). Reversible regulation by magnesium of chick embryo fibroblast proliferation. J. Cell Physiol. 94: 13-19.

Siebert, G. (1966). Nucleolar enzymes of isolated rat liver nucleoli. Natl. Cancer Inst. Monograph 23: 285-293.

Van Steveninck, R.F.M. (1979). The verification of cytochemical tests for ATPase activity in plant cells using X-ray microanalysis. Protoplasma 99: 211-220.

Vorbrodt, A. and Boun, T.W. (1979). Ultrastructural cytochemical studies of plasma membrane phosphatase activities during the HeLa S₃ cell cycle. J. Histochem. Cytochem. 27: 15961603.

Vorbrodt, A. and Maul, G.G. (1980). Cytochemical studies on the relation of nucleoside triphosphatase activity to ribonucleoproteins in isolated rat liver nuclei. J. Histochem. Cytochem. 28:27-35.

Wachstein, M. and Meisel, G. (1957). Histochemistry of hepatic phosphatases at a physiologic pH. Am. J. Clin. Pathol. 27: 13-23.

Wegmann, R. and Bankowsky, Z. (1960). Differentiation histochimique de quatre groupes d'adénosine triphosphatases selon Slater. Ann. Histochem. 5: 121-141.