[Nucleotide sequence of internal transcribed spacers and 5.8S rDNA for the ribosomal operon from alfalfa Medicago sativa and cotton Gossypium hirsutum L]. / Nukleotidnye posledovatel'nosti vnutrennikh transkribiruemykh speiserov i 5.8S rDNA ribosomnogo operona u liutserny Medicago sativa i khlopchatnika Gossypium hirsutum L.

The 708- and 769-bp fragments from alfalfa and cotton containing the 3'-end of the 18S gene, the internal transcribed spacer. 1 (ITS1) the 5.8S gene, ITS2, and the 5'-end of the 28S gene were obtained using primers to the 18S and 28S ends of rDNA from tomato by a polymerase chain reaction. These sequences were cloned into pTZ19R. The 5.8S rDNA, ITS1 and ITS2 nucleotide sequences of alfalfa and cotton were determined. Comparative analysis of nucleotide sequences of alfalfa and cotton showed large hypervariability of spacer regions and conservatism of 5.8S rDNA sequence.

[Mobilization of phase I plasmid in Shigella sonnei and stability of its inheritance in rough strains of Shigella and Escherichia]. / Mobilizatsiia plazmidy I fazy Shigella sonnei i izuchenie stabil'nosti ee nasledovaniia v sherokhovatykh shtammakh shigell i ésherikhii.

The plasmid pSS120, determining the synthesis of species specific I phase antigen of Shigella sonnei is mobilized for genetic transfer into E. coli K12 recipient cells with the frequency 12-41%. The frequency depends on the type of mobilized plasmid and recipient strain. The I phase antigen is normally expressed in II phase recipient cells and in E. coli cells. During mobilization pSS120 forms cointegrates representing a recombinant of mobilizing and mobilized plasmids DNA. The study of pSS120 inheritance stability has shown the plasmid to be unstable during culturing of bacteria and to be partially lost from the parent Shigella sonnei strains as well as from the "hybrid" transconjugants obtained. The 60 Md plasmid present in the donor strains of Shigella sonnei is prone to structural fragmentation particularly expressed in Shigella sonnei/E. coli hybrids.