24 research outputs found
REARRANGEMENT IN THE B-GENOME FROM DIPLOID PROGENITOR TO WHEAT ALLOPOLYPOLID
Three key periods that were accompanied by considerable rearrangements in the B genome of wheat and its progenitor can be considered. The first period covers the period from the divergence of diploid Triticum and Aegilops species from their common progenitor (2.5–6 million years ago) to formation of the tetraploid T. diccocoides (about 500 thousand years ago). Significant genomic rearrangements in the diploid progenitor of the B genome, Ae. speltoides (SS genome), involved a considerable amplification of repeated DNA sequences, which led to an increase in the number of heterochromatin blocks on chromosomes relative to other diploid Aegilops and Triticum species. Our analysis has demonstrated that during this period the Spelt1 repeats intensively amplified as well as several mobile elements proliferated, in particular, the genome-specific gypsy LTR-retrotransposon Fatima and CACTA DNA-transposon Caspar. The second period in the B-genome evolution was associated with the emergence of tetraploid (BBAA genome) and its subsequent evolution. The third most important event leading to the next rearrangement of the B genome took place relatively recently, 7000–9500 years ago, being associated with the emergence of hexaploid wheat with the genomic formula BBAADD. The evolution of the B/S genome involved intergenomic and intragenomic translocations and chromosome inversions. So far, five rearrangements in the B-genome chromosomes of polyploid wheats has been observed and described; the majority of them took place during the formation and evolution of tetraploid species. The mapping of the S-genome chromosomes and comparison with the B-genome chromosome maps have demonstrated that individual rearrangements pre-existed in Ae. speltoides; moreover, Ae. speltoides is polymorphic for these rearrangements.Chromosome 5B is nearly 870 Mbp (5BL = 580 Mbp and 5BS = 290 Mbp) and is known to carry important genes controlling the key aspects of wheat biology, in particular, Ph1, critical for correct mitosis and meiosis in the allopolyploid nucleus; Kr1, controlling interspecific incompatibility; the genes controlling hybrid necrosis and response to vernalization, Ne1 and Vrn-B1; and genes controlling resistance to various pathogens and bread-making quality. The translocations and inversions of chromosome 5B/5S, which could have taken place in the evolution of Ae. speltoides and allopolyploid wheats, yet has not been detected so far. On the other hand, the changes in chromosome 5B that had brought forth the locus Ph1 took place due to certain yet unknown mechanisms. Construction of the physical map for chromosome 5B and determination of its primary structure are in progress now
Enhancement of leaf rust resistance of Siberian winter wheat varieties by marker-assisted selection
Cultivation of winter wheat varieties in the West Siberian region of Russia has competitive advantages compared to spring varieties: utilization of spring-summer moisture, early maturation and harvest and a high yield potential. The poor resistance of winter varieties to foliar diseases results in significant yield losses and facilitates the spread of pathogens to the spring wheat cultivars. The present study was conducted to evaluate the effectiveness of molecular markers specific for VRN-1 and Lr loci in selecting winter wheat genotypes resistant to leaf rust. The winter wheat cultivars Biyskaya ozymaya and Filatovka were crossed with spring wheat introgression lines 21-4 and 5366-180 and the spring wheat cultivar Tulaikovskaya 10 carrying LrTt2, LrAsp5 and Lr6Ai#2 loci from Triticum timopheevii, Aegilops speltoides and Thynopyrum intermedium, respectively. To identify winter wheat plants homozygous for target loci, F2 populations were screened with functional markers to VRN-1 genes and with markers specific for alien genetic material. Based on the genotyping analysis of 371 F2 plants a total of 44 homozygous genotypes with winter habit was identified. There were eight genotypes containing Lr loci among them. Evaluation of F2-derived F3-4 families for both seedling and adult resistance showed that only one F3-4 family had moderate susceptible reaction type to the field population of leaf rust. Others ranged from nearly immune to resistant with severity of 5%. The data also indicated the utility of the VRN-1 allele-specific markers for detection of genotypes with winter habit without vernalization at early stages of plant breeding
Clinical and neuroimaging features vertebral radiculopathy in the combination with vertebral hemangiomas
<p><em>Aim of the study: t</em>o study the clinical and neuroimaging features of radiculopathy vertebral hemangiomas in conjunction with the vertebrae. <em>Materials and methods. </em>A total of 56 patients with radiculopathy vertebral hemangiomas combined with the vertebrae. <em>Results. </em>The patients in addition to pain, and focal neurological symptoms were observed violation of urination, and chronic venous insuffciency of lower extremities. MRI identifed three types of vertebral hem-angiomas, depending on the structural characteristics. <em>Conclusion</em>. The aim of the study is realized.Most hemangiomas are asymptomatic yourself. Pain and neurological symptoms caused by musculo-tonic component, the presence of disc herniation, changes in the intervertebral joints, ligaments violation. Type III meets the criteria for hemangiomas and requires aggressive surgical treatment.</p>
Pre-M Phase-promoting Factor Associates with Annulate Lamellae in Xenopus Oocytes and Egg Extracts
We have used complementary biochemical and in vivo approaches to study the compartmentalization of M phase-promoting factor (MPF) in prophase Xenopus eggs and oocytes. We first examined the distribution of MPF (Cdc2/CyclinB2) and membranous organelles in high-speed extracts of Xenopus eggs made during mitotic prophase. These extracts were found to lack mitochondria, Golgi membranes, and most endoplasmic reticulum (ER) but to contain the bulk of the pre-MPF pool. This pre-MPF could be pelleted by further centrifugation along with components necessary to activate it. On activation, Cdc2/CyclinB2 moved into the soluble fraction. Electron microscopy and Western blot analysis showed that the pre-MPF pellet contained a specific ER subdomain comprising "annulate lamellae" (AL): stacked ER membranes highly enriched in nuclear pores. Colocalization of pre-MPF with AL was demonstrated by anti-CyclinB2 immunofluorescence in prophase oocytes, in which AL are positioned close to the vegetal surface. Green fluorescent protein-CyclinB2 expressed in oocytes also localized at AL. These data suggest that inactive MPF associates with nuclear envelope components just before activation. This association may explain why nuclei and centrosomes stimulate MPF activation and provide a mechanism for targeting of MPF to some of its key substrates
Alterations in subtelomeric tandem repeats during early stages of allopolyploidy in wheat
PubMedID: 15499400The genomic content of the subtelomeric repeated sequences Spelt1 and Spelt52 was studied by dot, Southern, and in situ hybridization in 11 newly synthesized amphiploids of Aegilops and Triticum, and data were compared with the parental plants. Spelt1 had reduced copy numbers in the first generation of three synthetic amphiploids, but two others did not change; Spelt52 was amplified in nine amphiploids and did not change in two. In the second allopolyploid generation, Spelt1 copy number did not change, whereas there was amplification of Spelt52 in some allopolyploids and decreases in others. Neither allopolyploidy level nor the direction of the cross affected the patterns of change in the newly synthesized amphiploids. Changes did not result from intergenomic recombination because similar alterations were noticed in allopolyploids with and without Ph1, a gene that suppresses homoeologous pairing. No differences in Spelt1 and Spelt52 tandem organization were found by Southern hybridization. The significance of these data are discussed in relation to the establishment of newly formed allopolyploids
Application NO TGCH-therapy in complex treatment of postoperative lumbar localization radiculopathy
This paper presents the results of a survey of 50 patients to study the application of terahertz therapy of NO in the complex treatment of postoperative lumbar radiculopathy localization. Materials and methods. Using a visual analogue scale assessed the degree of regression of pain, depending on the nature of the therapy. For the diagnosis of intra-articular inflammation in the postoperative motor segment and a local mikrovaskulita determined the level of antibodies in the serum of patients to collagen and myeloperoxidase. The results suggest shortening pain and reducing the content of antibodies to MPO and collagen in patients receiving short-wave therapy. Therefore, we conclude that the use of NO therapy TGCH improves the treatment of postoperative lumbar radiculopathy localizatio
Decompressive stabilizing operations in the treatment of complicated aggressive hemangiomas of transitional spine.
The aim: to study the efficiency of surgical treatment of complicated aggressive hemangiomas in transitional spine. Material and Methods. Decompressive stabilizing operations were made to 26 patients aged 35-52 years with hemangiomas of vertebral bodies. Individual surgical features varied due to the character and level of the injury. Results. In the experimental patients' group in admission there was neurological deficit of compressional origin associated with the critical values of luminal narrowing due to the epidural component of the neoformation. Stable antalgic effect and decrease in neurological deficit were seen postsurgically. Conclusion. While choosing the surgical option of decompressive stabilizing treatment a surgeon should take into account roentgenomorphometric features of the injured vertebrae. Adequately planned intervention fulfilled with the account of the injury character allows obtaining favorable outcomes as well as LQ improvement, neurological deficit decrease and the elimination of pain syndrome.</p
Effciency of HIV-infected patients detection in neurological hospitals of large industrial center
<p><em>Aim of the study: </em>to evaluate the effciency of detection for HIV-infection in patients of neurological departments of Saratov. <em>Materials and methods. </em>We retrospectively analyzed 25 250 medical histories of patients hospitalized into neurological departments of Saratov hospitals between January 2007 and April 2012. <em>Results. </em>Blood samples of 2010 patients (7,96 %) were tested for the presence of HIV-antibodies. 37 patients were HIV-positive (1,84 % of examined patients and 0,15 % of the total number of patients). <em>Conclusion. </em>Increasing popularity and variety of clinical manifestations of HIV-infection requires the expansion of neurological patients whom serum test for antibodies against HIV is needed.</p>