Division-induced DNA double strand breaks in the chromosome terminus region of Escherichia coli lacking RecBCD DNA repair enzyme.

Marker frequency analysis of the Escherichia coli recB mutant chromosome has revealed a deficit of DNA in a specific zone of the terminus, centred on the dif/TerC region. Using fluorescence microscopy of a marked chromosomal site, we show that the dif region is lost after replication completion, at the time of cell division, in one daughter cell only, and that the phenomenon is transmitted to progeny. Analysis by marker frequency and microscopy shows that the position of DNA loss is not defined by the replication fork merging point since it still occurs in the dif/TerC region when the replication fork trap is displaced in strains harbouring ectopic Ter sites.

[FEATURES OF CLINICAL COURSE OF INFECTIOUS MONONUCLEOSIS IN CHILDREN DEPENDENT ON ETIOLOGY].

The article highlights the clinical features of infectious mononucleosis in children (based on the analysis of the data for children of different ages treated in Odessa clinical hospital of infectious diseases in connection with infectious mononucleosis) based on etiological factors.

[Assemblages of bloodsucking mosquito larvae (Diptera: Culicidae) in water bodies of the northern Kulunda steppe].

The population structure of bloodsucking mosquito larvae in temporary and constant water bodies of the northern Kulunda steppe was investigated. The seasonal dynamics of the population density, the number of species in different types of reservoirs, and average density of each species are given. The productivity of water reservoirs in relation to mosquitoes of the family Culicidae is analyzed.

[Species composition of mosquitoes (Diptera, Culicidae) and possibility of the West Nile virus natural foci formation in the South of Western Siberia].

In 2004 June-July collections of mosquito adults and small mammals were carried out in two areas of Novosibirsk Region (forest-steppe and steppe zones), where the West Nile virus (WNV) was for the first time recorded in birds with different migration status in 2002-2004. Seventeen species of mosquitoes were found; significant changes in their species composition and abundance, as compared with latest faunistic studies made in the sixties-seventies of the last century, are revealed. WNV markers (antigen, RNA) are found in small mammals; highly sensitive to the WNV replication mosquito species are also found.

[On the fauna and ecology of mosquitoes (Diptera: Culicidae) in forest-steppe and steppe regions of Western Siberia].

Fauna and ecology of the mosquitoes from the southern forest-steppe (Chany Lake) and the northern steppe (Karasuksky lakes) have been investigated during 2004-2006. Species composition, dominant species, biotopical and seasonal distribution are examined. Detailed data on the biotopical and seasonal distribution, sex ratio and terms of development for the dominant species Coquillettidia richiardii (Ficalbi, 1889) are reported.