Vol 10, No 1 (2012)

In the present work a molecular genetic analysis of the receptor part of the nfr5 gene in 15 plants of the conjugate collection (the plant component Melilotus albus, the bacterial component Sinorhizobium meliloti) has been done. Was studied the LysM domains structure and found a high level of the nucleotide polymorphism in LysM domains of this gene. A clear relationship of nucleotide and amino acid polymorphism in the receptor region of the nfr5 gene with the genetic diversity of the rhizobial component (bacterial symbiotic locus nodD) was observed. Based on these data, the computer modeling of binding of the bacterial Nod-factor with two different variants of the plant receptor was performed.

We studied genetic structure of populations of Karelian birch Betula pendula var. carelica (Mercklin) Hämet-Ahti, whichlacks second growth. Based on the values of expected and observed heterozygosity, the predominantselection of homozygotes on the background of decrease of the heterozygotes fraction was revealed. Interpopulation differentiation rate (Fst = 0,145) indicates a high inbreeding frequency. Observed genetic characteristics of the populationssuggest that genetic mechanisms play a role in the current decrease of thepopulation size of Karelian birch and its genetic degradation. 

 Using ethylmethansulphonate the chemical mutagenesis of the pea laboratory line SGE was performed. During analysis of 425 families (2069 plants) of М₂ progeny 45 putative mutants were selected, among them 30 mutants forming ineffective nodules (Fix^– phenotype), 13 mutantsunable to form nodules (Nod^– phenotype), and 2 mutants forming a few nodules (Nod^+/– phenotype). For 1 Nod^– and 5 Fix^– mutants monogenic inheritance and recessive phenotype manifestation were demonstrated. For Fix^– mutant SGEFix^––9 an additional mutation leading to Nod^+/– phenotype was shown. Complementation analysis showed that the mutant phenotype of the SGEFix^- - 5 line is caused by a mutation in the sym33 gene, of theSGEFix^––6 linein the sym40 gene, of the SGEFix^––7 line in the sym27 gene, and of the SGEFix^––8 linein the sym25 gene.

A pea mutant SGECdt (cdt), which has an increased cadmium tolerance and an increased cadmium accumulation, as compared to the initial line, was recently obtained. Earlier, a SSAP (sequence specific amplified polymorphism) analysis revealed localization of the cdt locus in VI linkage group. For fine mapping of the cdt locus a set of PCR based markers was developed. PCR markers were based on known sequences of pea genes, which were determined using analysis of genome microsynteny between pea and model legume Medicago truncatula. The close linkage of the cdt locus and markers based on the Pentatricopeptide repeat and Exosome complex exonuclease RRP 45 genes was revealed. Thus, prerequisites for cdt positional cloning were developed.

SUMMARY: The possibility of interaction between Prion Protein and amyloid beta peptide in living cells of yeast Saccharomyces cerevisiae have been investigated by fluorescence 3D microscopy. Using the FR ET technique, it was shown that amyloid beta peptide and PrP interact in yeast cells. In the future, the yeast model can be used for investigation of the fine mechanisms of this interaction by fluorescence microscopy.