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Biomedical subjects

V Z Tarantul

Publications and source records attributed to V Z Tarantul.

At least 19 recordsLinked to original sources

[Biological effect of human erythropoietin in transgenic mice].

Transgenic mice were obtained inheriting the human erythropoietin gene under the control of viral regulatory elements. The reliable difference in haematocrit, the content of haemoglobin and percentage of reticulocytes in peripheral blood were not revealed. The level of serum erythropoietin in transgenic mice is several fold higher than in control mice. The increased pool of erythroid cells was observed in the bone marrow of transgenic mice, especially of normoblasts (3-fold) and reticulocytes (4,5-fold).

Animals

[Molecular and cytologic analyses of the transcription of evolutionarily conservative moderately repetitive sequences of vertebrate genomes].

Transcription of several families of moderately repeated sequences, conserved through the evolution of vertebrates, has been studied in different types of pigeon, chicken and mouse cells. It is shown both by hybridization with isolated RNA and by in situ hybridization that the families of repeats, dispersed in bird genomes and organized in clusters, are differentially expressed in pigeon erythroid cells with different degrees of specialization; in addition, they are transcribed in different types of chick embryo cells and on lampbrush chromosomes in chicken oocytes. Sequences homologous to these repeats were transcribed in different types of newborn mouse cells. Another family of conservative moderate repeats (family T1) dispersed in the mouse genome was also transcribed in a large variety of tissues in both new-born mice and chick embryos. A comparison of structural and transcription features of conservative moderate repeats represented in genomes of the number of vertebrates made it possible to regard them as "housekeeping" elements. The conservation in the evolution as well as the character of transcription of similar genome elements testify to their important role in the organism functioning at different stages of development.

Animals

[New data on the type of structural changes in DNA of simian adenovirus SA7 microinjected into mouse zygotes].

The structure of the transgene has been analysed in a new series of experiments on the transfer of adenovirus SA7 DNA into the mice zygotes by microinjection technique. The previous data on SA7 DNA elimination from the genomes of different organs (sceletal muscles, heart, tail) have been confirmed and detailed for the F0 and F1 generations of transgenic animals. The left end of adenoviral genome has been shown to be predominantly transfered after microinjections of SA7 DNA into the mice zygotes.

Adenoviridae

[Production of transgenic rabbits and mice carrying the gene for bovine growth hormone].

The results of experiments on the transfer of bovine gene for growth hormone into mice and rabbits are presented. The gene was transferred by the technique of microinjection into the zygote. In all cases transgene in rabbits occurred to be changed. In two transgenic mice the bovine growth hormone gene represented some tandem arranged copies. One of the mice had accelerated growth. This phenotypic changes is found to be inheritable.

Animals

Rearrangements of microinjected recombinant DNA in the genome of transgenic mice.

Previously, mouse zygotes were microinjected with the recombinant plasmid pMA3, which contains the Herpes simplex virus thymidine kinase gene attached to the promoter region of the Rous sarcoma virus (Gazaryan et al. 1984a). In the present work the pMA3 fragment with the flanking genomic sequences was isolated from the DNA of one transgenic Fo mouse by the "plasmid rescue" technique. The rescued plasmid (pMAR1) lacked all virus-specific sequences and retained only some pBR322 sequences. The flanking region at one end of the integrated pBR322-specific fragment contained a highly conserved mouse repetitive sequence. The possible mechanisms of rearrangement of foreign DNA in germ line cells are discussed.

Animals

[Transcription, in frog oocytes and transgenic mice, of recombinant plasmids with long terminal repeats of retrovirus proviruses].

RNA-DNA hybridization was used to study the transcription efficiency of the genes controlled by the long terminal repeats (LTR) from two different retroviral proviruses (exogenous provirus of the chicken Rous sarcoma virus and endogenous xenotropic provirus of the mouse). The oocyte nuclei of Xenopus laevis and the liver of transgenic mice were used as the transcription systems. The transcription efficiency of genes with the above mentioned promoters was shown to be roughly the same for both systems. Thus, the LTR of two proviruses of different origin possess the promoters of comparable strength and do not show any marked tissue or species specificity.

Animals

[Molecular organization and genome expression in eukaryotes].

The recent data on the structural organization and expression of genome in eukaryotes are reviewed. Different types of nucleotide sequences (repetitions, palindromes, homopolymers) represented in the regions of genome transcription, as well as in mRNA's of the cytoplasm and nuclear messenger-like RNA's are analyzed. Probable functions of different types of sequences are discussed. The problem of nuclear precursors of cytoplasmic mRNA's and in particular heterogeneous nuclear RNA is considered. It is noted that this population of molecules is heterogeneous not only by the molecular weight, but also by some other parameters. Stable messenger-like 28S and 18S RNA's found in the nuclei are described. In addition to the already known scheme of rapid posttranscriptional processing of pre-mRNA, a hypothesis is put forward to the effect that the selective transport of mRNA molecules stored in the nucleus from the nucleus into the cytoplasm is realized at the expense of extended processing.

Animals

[Structure of the mRNA of eukaryotic cells].

A review is given of the principal achievements in studying the structure of mRNA in eukaryotic cells. The data are provided on the size and life time, complexity and distribution of different kinds of mRNA by the frequency of repetitions; composition and structure of mRNP. The structures of individual mRNA's and general pattern of the structure of eukaryotic mRNA and mRNP are considered.

Animals

Purification and characterization of two transcribed repetitive DNA fractions from the pigeon genome.

Two fractions of the repeats belonging to intermediate frequency repetitive DNA were isolated from the total pigeon nuclear DNA fragmented to about 450 nucleotides. One fraction was designated as "rare repeats" (repetition frequency about 35 per haploid genome) and another termed as "moderate repeats" (repetition frequency about 2500 per haploid genome). The rare repeats, which constitute about 7% of the total DNA, include at least 75% of the repetitive DNA sequences transcribed into the high molecular fraction (greater than 45S) of HnRNA in erythroid cells. These repeats have properties compatible with the characteristics of the class of low frequency interspersed DNA found in genomes of many other Metazoan species. The moderate repeats contribute only about 10-20% of the total repetitive DNA copies present in greater than 45S HnRNA and differ from the rare repeats in some other properties.--The possible role of the rare repeats in the genome is discussed.

Animals