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V I Prima

Publications and source records attributed to V I Prima.

11 recordsLinked to original sources
PubMed2000

Growth protocols for etiolated soybeans germinated within BRIC-60 canisters under spaceflight conditions.

As part of the GENEX (Gene Expression) spaceflight experiment, protocols were developed to optimize the inflight germination and subsequent growth of 192 soybean (Glycine max cv McCall) seeds during STS-87. We describe a method which provided uniform growth and development of etiolated seedlings while eliminating root and shoot restrictions for short-term (4-7 day) experiments. Final seedling growth morphologies and the gaseous CO2 and ethylene levels present both on the last day in space and at the time of recovery within the spaceflight and ground control BRIC-60 canisters are presented.

Carbon Dioxide↗
PubMed1991

[Cycle dependent expression of the gene coding for B2mRNA].

The relative contents of individual tissue specific RNA B2mRNAx was studied in the population of nuclear and poly(A)+ cytoplasmic RNA from the livers of intact, falsely operated and having suffered the partial liver resection rats. Dot-hybridization technique was used to study this transcript containing the transcribed copy of the B2 repetitive genetic element of rats. The expression of the gene coding for B2mRNAx takes place at the lower level in the liver induced to proliferation as compared with the one in the liver of intact animals. It is changed reproducibly in antiphase with the c-fos RNA and with major inclinations at the moments of cellular phases switch.

Animals↗
PubMed1986

[Effect of monovalent cations on the ratio of RNA transcripts from DNA with different repetitive sequences in leukemia P-388 cells].

Using leukemic P-388 cells, it was demonstrated that alterations of the intracellular Na+/K+ ratio results in qualitative changes of newly synthesized mRNA, which manifests itself as changes in the kinetics of hybridization of heterogeneous nuclear RNA (hnRNA) with DNA. The decrease of the Na+/K+ value from 3.8:1 to 1:1 leads to inhibition of mRNA synthesis in mRNA cells hybridized at 10(3) greater than Dot greater than 10(4), but weakly affects the transcription of mRNA sequences hybridized with DNA within the Dot interval of 10(3.4)-10(3.8). A similar phenomenon is observed during hybridization of hnRNA with homogeneous fractions of unique and averagely repeating sequences of DNA. The hybridization rate constants of hnRNA synthesized by cells at different values of Na+/K+ and the limit values of hybridization (H infinity) were calculated. It was shown that the rate constants for RNA hybridization with DNA decrease by more than two orders of magnitude during the transition of the averagely repeating DNA fraction to the unique one; however, in both cases these constants give equal values for the RNA synthesized by cells at different cationic balance. The H infinity values for the RNA synthesized by cells at higher Na+ ratio appeared to be 1.5-2.0 times as high as compared with those for the RNA in the cells, in which the Na+/K+ ratio was 1:1. Thus, the monovalent cation ratio seems to exert a strong influence on the expression of sequences of different repeatedness in the genome and to play a role in the regulation of proliferative activity of the cell.

Animals↗
PubMed1982

[Features of nuclear genome transcription at early steps of liver regeneration: expression of DNA fractions with different repeating sequence frequencies].

The mode of hybridization of dRNA fraction from normal and regenerating rat liver with purified fractions of repeating and unique sequences of DNA was studied. In order to repress the reassociation of DNA the nucleic acids were annealed in a solution of 2 x SSC--80% formamide at 48 degrees. The differential hybridization curves suggest that the amount of transcripts with a high DNA sequence frequency increases, while the complexity of transcripts of unique DNA sequences decreases 3 hrs after partial hepatectomy. Simultaneously the amount of RNA transcribed from the unique and moderately repeating DNA fractions remains practically unchanged.

Animals↗
PubMed1980

[Reassociation of rat DNA fractions].

A method for direct registration of the first derivative of DNA reassociation kinetics in spectrophotometric cuvettes is proposed. Using this method, the rat liver DNA obtained by chromatography on hydroxyapatite was studied. The differential curves of reassociation and changes in hyperchromic spectra revealed the presence in the rat genome of 4 types of repeating sequences differing in their GC-content. A scheme of preparative separation of DNA with respect to the reassociation rate was developed. Three types of sequences repeating 3.10(5), 600 and 1 times in the genomes with the GC-content of 50, 42, and 33%, respectively, were obtained in a homogeneous state. The advantages of the differential method of registration of the kinetic curves for the study of DNA structure and calculation of fractionation schemes are discussed.

Animals↗
PubMed1979

Macromolecular structure of nuclear polyhedrosis virus genome.

DNA preparations from nuclear polyhedrosis virus (NPV) of Galleria mellonella L. (GmL) were fractionated in high ionic strength neutral sucrose gradient. This procedure allowed a separation of supercoiled infectious DNA molecules with contour length of 48--52 microns from infectious open ring DNA molecule, and noninfectious linear DNA molecules of the same size. In addition a heterogeneity of supercoiled DNA molecules was detected. Covalently closed DNA molecules did not contain protein or ribonucleotide ligands which could be digested by pronase or pancreatic RNase treatment. It is concluded from data on the infectivity of different molecular forms of DNA and reassociation kinetics studies, that the genome of GmL NPV is a unique ring nucleotide sequence with a molecular weight of about 90--100 X 10(6).

Animals↗