[Embryonal cell hybrids: new opportunities for studying pluripotency and reprogramming of the differentiated cell chromosomes]. / Embrional'nye gibridnye kletki: novye vozmozhnosti v izuchenii pliuripotentnosti i reprogrammirovaniia khromosom diffenetsirovannykh kletok.

Here we study the properties of cell hybrids produced by the fusion of embryonal stem cells and differentiated ones. During in vitro cultivation, such hybrids predominantly lose the somatic partner chromosomes, although the loss of the embryonic partner autosomes 1, 9, 11, 12, 15, 16, 18, and 19 is also common in the clones; i.e., this is a bidirectional process. The use of a selective media allows the isolation of the clones, with the embryonal X chromosome replaced by the somatic genome homolog. The cell hybrids with a near-diploid chromosome set preserve the high-level pluripotency properties of the embryonal partner including the capacity to form chimeras after their introduction in the blastocoel. An investigation of the chimeric animals demonstrated a reprogramming of the "somatic" X chromosome in the course of development. The prospective identification of the chromosomes involved in the maintenance of pluripotency and studies of its cis- and trans-regulation in the cell hybrid genome are discussed.

[Chromosome localization and analysis of synteny analysis of some genes in swine, cattle, and sheep (Artiodactyla)]. / Khromosomnaia lokalizatsiia i analiz sintenii nekotorykh genov u svin'i, korovy i ovtsy (otriad Artiodactyla)]

Using the hybrid cell lines pig-American mink, cow-American mink, and sheep-American mink, the localization of some genes included in a large conservative block localized on human chromosome (chr) 17 was performed by means of electrophoresis of proteins and Southern blot hybridization. Genes NF1, RARA, PRKCA, and ERBB2 were assigned to chr 12 in swine; TK1 and UMPH2, to chr 19 in cattle; and TK1, UMPH2, and PEPA, to chr 11 in sheep. The conserved synteny of these genes in three representatives of the order Artiodactyla was shown.

[The isolation and analysis of the highly repetitive DNA from the argali]. / Vydelenie i analiz vysokopovtoriaiushcheisia DNK arkhara.

The repeated DNA sequence of wild ram (Ovis ammon) of 800 bp has been cloned. The blot-hybridization, in situ-hybridization, sequencing and computer analysis were used for the sequence analysis. It was shown that the cloned DNA is from 1.714 gm/cm3 repeated satellite DNA family. Fourteen highly homologous sequences were revealed in the nucleotide sequence databases. An analysis of their alignment revealed presence of two subfamilies (A and B). Average divergence of subfamily A. sequences (including the wild ram repeated sequence) from consensus is about 1%.

[Feasibility of analysis of macroevolutionary rearrangements of mammalian chromosomes]. / Vozmozhnosti analiza makroévoliutsionnykh preobrazovanii khromosom mlekopitaiushchikh.

In the Institute of Cytology and Genetics, Siberian Division, Russian Academy of Sciences, detailed studies on chromosome sets of humans and domestic animals were initiated and supported by D.I. Belyaev and started by S.I. Radzhabli. They believed that analysis of differentially stained chromosomes and mapping of the genomes of main commercial species provide for a better understanding of the processes that occurred during their evolution and domestication. Several new approaches to studying macroevolutionary karyotypic rearrangements associated with divergence of remote taxa, such as primates and paridigitate ungulates, are discussed.