Genome comparisons reveal a dominant mechanism of chromosome number reduction in grasses and accelerated genome evolution in Triticeae.

Single-nucleotide polymorphism was used in the construction of an expressed sequence tag map of Aegilops tauschii, the diploid source of the wheat D genome. Comparisons of the map with the rice and sorghum genome sequences revealed 50 inversions and translocations; 2, 8, and 40 were assigned respectively to the rice, sorghum, and Ae. tauschii lineages, showing greatly accelerated genome evolution in the large Triticeae genomes. The reduction of the basic chromosome number from 12 to 7 in the Triticeae has taken place by a process during which an entire chromosome is inserted by its telomeres into a break in the centromeric region of another chromosome. The original centromere-telomere polarity of the chromosome arms is maintained in the new chromosome. An intrachromosomal telomere-telomere fusion resulting in a pericentric translocation of a chromosome segment or an entire arm accompanied or preceded the chromosome insertion in some instances. Insertional dysploidy has been recorded in three grass subfamilies and appears to be the dominant mechanism of basic chromosome number reduction in grasses. A total of 64% and 66% of Ae. tauschii genes were syntenic with sorghum and rice genes, respectively. Synteny was reduced in the vicinity of the termini of modern Ae. tauschii chromosomes but not in the vicinity of the ancient termini embedded in the Ae. tauschii chromosomes, suggesting that the dependence of synteny erosion on gene location along the centromere-telomere axis either evolved recently in the Triticeae phylogenetic lineage or its evolution was recently accelerated.

BAC libraries of Triticum urartu, Aegilops speltoides and Ae. tauschii, the diploid ancestors of polyploid wheat.

Triticum urartu, Aegilops speltoides and Ae. tauschii are respectively the immediate diploid sources, or their closest relatives, of the A, B and D genomes of polyploid wheats. Here we report the construction and characterization of arrayed large-insert libraries in a bacterial artificial chromosome (BAC) vector, one for each of these diploid species. The libraries are equivalent to 3.7, 5.4 and 4.1 of the T. urartu, Ae. speltoides, Ae. tauschii genomes, respectively. The predicted levels of genome coverage were confirmed by library hybridization with single-copy genes. The libraries were used to estimate the proportion of known repeated nucleotide sequences and gene content in each genome by BAC-end sequencing. Repeated sequence families previously detected in Triticeae accounted for 57, 61 and 57% of the T. urartu, Ae. speltoides and Ae. tauschii genomes, and coding regions accounted for 5.8, 4.5 and 4.8%, respectively.

[Effect of strophanthin on the electrophoretic mobility of blood erythrocytes in adults and children]. / Vliianie strofantina na élektroforeticheskuiu podvizhnost' éritrotsitov krovi vzroslykh i detei.

As assessed by changes in the erythrograms asymmetry coefficient, selectivity of the strophantin effect on cell populations with different mobility and age specifics of reciprocal responses, was revealed in adult subjects and in children. The data obtained suggest existence of difference in quality of functional condition of the erythrocytes with normal as well as reduced mobility in children and in adults.

[Electrophoretic mobility and oxidizing status of rat blood erythrocytes at scald trauma]. / Elektroforeticheskaia podvizhnost' i okislitelnyl status eritrotsitov krys pri ozhoge.

On model of scald trauma the correlation of electrophoretic mobility of rat blood erythrocytes with intensity of lipid oxidation of erythrocyte membranes and with activity of catalase were studied. It is shown that in dynamics of scald disease development the erythrocyte mobility decreases, the velocity of oxidizing ability of their lipids increases and the protective action of blood antioxidation system is blocked. It is found that there is a close dependence between the level of oxidative processes and electrogenic properties of erythrocytes at the height of manifestation of scald toxaemia. A conclusion was made that the oppressing influence of increasing lipid oxidizing ability a on electrokinetic potential of erythrocytes is of a threshold nature and is realized through change in the membranes' state of these cells.

[The electrophoretic mobility of the erythrocytes in rats during body adaptation to low-temperature exposure]. / Elektroforeticheskaia podvizhnost' éritrotsitov krovi krys pri adaptatsii organizma k vozdeistviiu nizkoi temperatury.

The action of a low temperature (-4 degrees C) on electrophoretic mobility of rat blood erythrocytes (EME) was studied. The stress provoked by the low temperature renders a considerable influence on EM of erythrocytes, but the degree and disposition of arising changes depend on the duration of temperature coercion. Two weeks after conducting cooling seances (beginning with 15 min, with an every day increase in exposition by 10 min), the response reaction was manifested in the rise of asymmetry and excess of distribution curve of EME index. The prolongation of cold adaptation to 6 weeks was accompanied with the authentic lowering of the mean mobility of cells, in addition to a subsequent sharp modification of erythrogram profile. The cooling of animals conducted against the background of thyreoidine has given, as a whole, similar results, although the use of the protector alleviated the consequences of low temperature coercion.