Dynamics of the Centromeric Histone CENH3 Structure in Rye-Wheat Amphidiploids (Secalotriticum)

The centromeres perform integral control of the cell division process and proper distribution of chromosomes into daughter cells. The correct course of this process is often disrupted in case of remote hybridization, which is a stress factor. The combination of parental genomes of different species in a hybrid cell leads to a “genomic shock” followed by loss of genes, changes in gene expression, deletions, inversions, and translocations of chromosome regions. The created rye-wheat allopolyploid hybrids, which were collectively called secalotriticum, represent a new interesting model for studying the effect of remote hybridization on the centromere and its components. The main feature of an active centromere is the presence of a specific histone H3 modification in the centromeric nucleosomes, which is referred to as CENH3 in plants. In this paper the results of cytogenetic analysis of the secalotriticum hybrid karyotypes and the comparison of the CENH3 N-terminal domain structure of parent and hybrid forms are presented. It is shown that the karyotypes of the created secalotriticum forms are stable balanced hexaploids not containing minichromosomes with deleted arms, in full or in part. A high level of homology between rye and wheat enables to express both parental forms of CENH3 gene in the hybrid genomes of secalotriticum cultivars. The CENH3 structure in hybrids in each crossing combination has some specific features. The percentage of polymorphisms at several amino acid positions is much higher in one of the secalotriticum hybrids, STr VD, than in parental forms, whereas the other hybrid, STr VM, inherits a high level of amino acid substitutions at the position 25 from the maternal parent

Структурные и фазовые превращения в зонах контакта Al-Ti, Al-Ni и сплава AMr7 при пластической деформации

Work is devoted research of features of structure formation processes in the contact zone of limited solubility bimetals and alloys subjected to plastic deformation. It is established, that the plastic deformation of limited solubility metals (Al-Ti, Al-Ni), can significantly broaden the scope of their mutual solubility. The appearance of zones of local tensile and compressive stresses (curvature crystal lattice zones) leads to increased solubility, emergence of new phases and redistribution of their composition, reorientation of granular structureРабота посвящена исследованию особенностей процессов формирования структуры в зоне контакта биметаллов с ограниченной растворимостью и сплавов, подвергнутых пластической деформации. Установлено, что пластическая деформация металлов c ограниченной растворимостью (Al-Ti, Al-Ni) может значительно расширить область их взаимной растворимости. Появление зон локального растяжения и сжимающих напряжений (зон кривизны кристаллической решетки) приводит к увеличению растворимости, появлению новых фаз и перераспределению их состава, переориентации зернистой структур

Структурные и фазовые превращения в зонах контакта Al-Ti, Al-Ni и сплава AMr7 при пластической деформации

Work is devoted research of features of structure formation processes in the contact zone of limited solubility bimetals and alloys subjected to plastic deformation. It is established, that the plastic deformation of limited solubility metals (Al-Ti, Al-Ni), can significantly broaden the scope of their mutual solubility. The appearance of zones of local tensile and compressive stresses (curvature crystal lattice zones) leads to increased solubility, emergence of new phases and redistribution of their composition, reorientation of granular structureРабота посвящена исследованию особенностей процессов формирования структуры в зоне контакта биметаллов с ограниченной растворимостью и сплавов, подвергнутых пластической деформации. Установлено, что пластическая деформация металлов c ограниченной растворимостью (Al-Ti, Al-Ni) может значительно расширить область их взаимной растворимости. Появление зон локального растяжения и сжимающих напряжений (зон кривизны кристаллической решетки) приводит к увеличению растворимости, появлению новых фаз и перераспределению их состава, переориентации зернистой структур