Vol 11, No 4 (2013)

Analysis of current data concerning functioning, structural organization and evolutionary aspects of origin for a unique class of the plant LysM-receptors has been performed. Plant receptors with LysM-motifs in the extracellular domain act as mediators in recognition of N-acetylglucosamine-containing compounds. Such compounds from pathogenic bacteria and fungi cause activation of plant defense systems, while the compounds secreted by symbiotic microorganisms trigger endosymbiosis formation. A possible mode of receptor operation in binding of structurally similar microbial signals, that leads to pathogen resistance or endosymbiosis development, as well as the role of LysM-receptors in these processes, have been examined.

This review considers evolution of multigene families based on the example of the PHO gene family, which encodes acid phosphatases. An analysis of databases revealed that the divergence of regulation of structural genes transcription and their involvement in novel regulatory pathways, is the main direction in evolution of multigene families.

Background. Agonistic behavior is necessary for formation of dominant-subordinate relationship and for maintenance of social hierarchy in animal communities. However? there are few reports about the genetic features of agonistic behavior development in animals living in stable social groups. The aim of the present study was to investigate the ontogeny of agonistic behavior in male mice of different genotype and social status under stable social hierarchy conditions. Materials and methods. We studied the age dynamics of offensive attacks, the vertical defensive postures and the “runaway” behavior in male mice of inbred strains PT and CBA/Lac housed in genetically heterogeneous pairs during puberty (from 38 to 70 days of life). Results. Dominant-subordinate relationships were stable in 80 % of pairs during the experiment. During the period of stable social hierarchy we observed a transient increase in the number of offensive attacks at the end of puberty in dominants of the strain CBA/Lac but not in PT. Conclusion. In conclusion, the study revealed a significant influence of social rank and genotype on the development of patterns of social behavior in laboratory male mice during puberty.

Background. Distribution of root nodule bacteria of soybean in soils of Ukraine is the result of intensive cultivation of soybeans over the last 20 years. During the observation the structure of soybean rhizobia populations for the first time we have determined the strains which significantly differ in phenotypic properties from typical slow-growing bacteria of B. japonicum species previously described. These strains are characterized by high speed growth and we tentatively called them “stains with intensive growth”. The aim of our work was to investigate the genotypic properties of microsymbionts of soybeans with different rates of growth spreading in soils of Ukraine. Materials and methods. The 16S rRNA gene and intergenic 16S-23S rRNA region of six strains - typical representatives of soybean nodule bacteria with slow- and intensive growth-rates was carried out. The strains were picked up from different Ukrainian soils. Results. Analysis of the 16S rRNA nucleotide sequences showed the 100% similarity of slow-growing strains to B. japonicum USDA 6T and USDA 4 ones. This analysis proved propinquity of strains with intensive growth to the strain B. japonicum USDA 127 (USDA 123 group). Representatives of this group possessed increased saprophytic competence so as the examined strains. With use of restriction analysis of ITS intergenic region soybean rhizobia were divided among two ITS types: 1st ITS type - strains with intensive growth, 2nd ITS type - slow- growing strains. According to results of ITS-region sequencing soybean rhizobia form 3 reliably different clusters: two of which include slow-growing strains (group USDA 6 and USDA 4), and a third include soybean microsymbionts with intensive growth (USDA 123 group). Conclusion. On the basis of phenotypic and genotypic (16S rRNA and 16S-23S rRNA) analysis all of the investigated soybean strains of root nodule bacteria were related to the Bradyrhizobium japonicum species. The division of strains by the structure of the ITS-region into two genotypes corresponds to the division of strains into two physiological groups: the strains of an intense and slow growth.