[Evolution and Comparative Genomics of the pSM22 Plasmid of the IncF/MOBF12 Group].

A new plasmid, pSM22, was isolated from Serratia marcescens and sequenced. Its 43 190-bp sequence with an average GC-content of 58% contains 31 open reading frames (ORFs) which form replication, conjugation, stability, and adaptive modules. The replication module includes a site of initiation of leading-strand synthesis in plasmid replication, a replication termination site (terC), the rep A (=repA1) and repA4 genes, and the copA sequence, which codes for an antisense RNA (asRNA). These structures are functionally integrated in an FII replicon (incompatibility group IncFII). Based on the significant differences between the FII replicon and the canonical sequences of the R plasmids R1 and NR1 (=R100=R222), pSM22 was assigned to a new subtype. The conjugation module includes 13 genes with a high identity to the genes responsible for conjugation of the F plasmid. A comparative genomic analysis showed that the conjugation modules of pSM22 and F are structurally similar. By the conjugation system and the presence of three conserved motifs in relaxase (TraI), pSM22 belongs to the F12 clade of the MOBF type. The stability module includes the resD and parA genes, which are responsible for the resolution of multimeric plasmid forms and their subsequent segregation between daughter cells. The adaptive module contains the microcin H47 (MccH47) secretion/processing and UV resistance genes. The mosaic structure of pSM22 and reductive evolution of its modules suggest high genomic plasticity for the genus Serratia. An analysis of the architecture of the pSM22 modules clarifies the evolutionary relationships among IncF/MOBF12 group plasmids in bacteria of the family Enterobacteriaceae and opens a novel avenue for further comparative genomic studies of Serratia plasmids.

[THE COMPARATIVE ANALYSIS OF INFORMATION VALUE OF MAIN CLINICAL CRITERIA USED TO DIAGNOSE OF BACTERIAL VAGINOSIS].

The bacterial vaginosis is one of the most frequent causes of women visiting gynecologist. The diagnostics of bacterial vaginosis is predominantly based on Amsel criteria (1983). Nowadays, the objectivity of these criteria is disputed more often. The analysis of excretion of mucous membranes of posterolateral fornix of vagina was applied to 640 women with clinical diagnosis bacterial vaginosis. The application of light microscopy to mounts of excretion confirmed in laboratory way the diagnosis of bacterial vaginosis in 100 (15.63%) women. The complaints of burning and unpleasant smell and the Amsel criterion of detection of "key cells" against the background of pH > 4.5 were established as statistically significant for bacterial vaginosis. According study data, the occurrence of excretions has no statistical reliable obligation for differentiation of bacterial vaginosis form other inflammatory pathological conditions of female reproductive sphere. At the same time, detection of "key cells" in mount reliably correlated with bacterial vaginosis.

[Raoultella planticola, a new strain degrading 2,4,5-trichlorophenoxyacetic acid].

A new strain that degrades the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was isolated from soil, which was exposed to factors related to the petrochemical industry. According to its physiological, biochemical, cultural, and morphological traits, together with the sequence of the 16S rRNA gene, the strain was identified as Raoultella planticola 33-4ch. The strain could consume 2,4,5-T as a sole source of carbon and energy. The amount of 2,4,5-T in the culture medium decreased by 51% after five days of incubation. Raoultella planticola 33-4ch consumes 2,4,5-T to produce 4-chlorophenoxyacetic, phenoxyacetic, and 3-methyl-2,6-dioxo-4-hexenoic acids.

[Identification and characterization of a plasmid in strain Aeronomas hydrophila IBRB-36 4CPA carrying genes for catabolism of chlorophenoxyacetic acids]. / Identifikatsiia i kharakteristika plazmidy shtamma Aeronomas hydrophila 1BRB-36 4CPA, nesushchei geny katabolizma khlorfenoksiukusnykh kislot.

Results of studying plasmid pAH36 in strain Aeronomas hydrophila IBRB-36 4CPA are presented. Plasmid pAH36 possesses BamHI, PstI, and HindIII restriction sites and is 5.4 kb in size. The plasmid was shown to contain genes for catabolism of chlor-substituted phenoxyacetic acids.

[Nucleotide sequence of the repetitive B2 region of the mouse genome]. / Posledovatel'nost' nukleotidov povtoriaiushchegosia élementa B2 genoma myshi.

Mouse genome contains two major families of short interspersed repeats in more than 10(5) copies and scattered throughout the whole genome. They were named as B1 and B2 sequences since they were first isolated from the genome library by means of a dsRNA-B probe. Three copies of B2 family were sequenced and compared with previously sequenced B1 repeat. B2 ubiquitous repeat is of ca. 180 bp long. The members of the family deviate by 5% of nucleotides from the consensus sequence. B2 contains the regions of homology to RNA polymerase III split promoter and to 4.5 S snRNA I. In contrast to B1, it does not contain clear homologies to exon-intron junctions, papova replication origins and human Alu-sequence. One side of B2 repeat is represented by a very AT-rich sequence (30 bp long) followed with an oligo(A) stretch 10-15 nucleotides long. This region of the repeat is the most variable one. The unit is flanked by 15-16 bp direct repeats different in sequenced copies of B2. The same is true for some copies of B1 family. The properties of B1 and B2 repeats suggest that they represent a novel class of transposon-like elements of eukaryotic genome. The possible role of B-type repeats in genome reorganization, DNA replication and pre-mRNA processing is discussed.

Ubiquitous transposon-like repeats B1 and B2 of the mouse genome: B2 sequencing.

Mouse genome contains two major families of short interspersed repeats in more than 10(5) copies scattered throughout the whole genome. They are referred to as B1 and B2 sequences since they were first isolated from the genome library by means of a dsRNA-B probe /1/. In this work, two copies of the B2 family were sequenced and compared with the previously sequenced B1 repeat /2/. A B2 ubiquitous repeat is ca. 190 bp long. The members of the family deviate in 3-5% of nucleotides from the consensus sequence. B2 contains regions of homology to the RNA polymerase III split promoter and to 4.5S snRNA I. Both B1 and B2 contain regions which resemble junctions between exons and introns. In contrast to B1, B2 does not contain apparent homologies to papova viral replication origins and a human Alu sequence. One side of the B2 repeat is represented by a very AT-rich sequence (ca. 30 bp long) followed with an oligo (dA) stretch 10-15 nucleotides long. This region of the repeat is the most variable one. The whole unit is flanked with 15-16 bp direct repeats different in sequenced copies of B2. The same is true of some copies of the B1 family. The properties of B1 and B2 repeats suggest that they may represent a novel class of transposon-like elements in eukaryotic genome. A possible role of B-type repeats in genome reorganization, DNA replication and pre-mRNA processing is discussed.

[Certain properties of transcribed fragments of the mouse genome cloned in plasmid pBR322]. / Nekotorye svoistva transkribiruishchikhsia fragmentov genoma myshi, klonirovannykh v sostave plazmidy pBR322.

Clones of total mouse DNA efficiently hybridized with mRNA (or cDNA) were selected by colony hybridization technique. The majority of selected fragments demonstrate hybridization with cDNA, dsRNA-B (isolated from pre-mRNA) and oligo(dT). The data obtained indicate that the base sequences hybridizing to these test-probes are contiguous within several individual cloned restriction DNA fragments. At least in two cases sequences hybridizing with cDNA belong to repetitive fraction of the mouse genome (presumptive repetitive structural genes). They are transcribed effectively, and respective mRNAs of abundant type. Two other clones contain structural genes which are expressed into mRNAs of non-abundant type.