35 research outputs found

    The impact of Ty3-gypsy group LTR retrotransposons Fatima on B-genome specificity of polyploid wheats

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    <p>Abstract</p> <p>Background</p> <p>Transposable elements (TEs) are a rapidly evolving fraction of the eukaryotic genomes and the main contributors to genome plasticity and divergence. Recently, occupation of the A- and D-genomes of allopolyploid wheat by specific TE families was demonstrated. Here, we investigated the impact of the well-represented family of <it>gypsy </it>LTR-retrotransposons, <it>Fatima</it>, on B-genome divergence of allopolyploid wheat using the fluorescent <it>in situ </it>hybridisation (FISH) method and phylogenetic analysis.</p> <p>Results</p> <p>FISH analysis of a BAC clone (BAC_2383A24) initially screened with Spelt1 repeats demonstrated its predominant localisation to chromosomes of the B-genome and its putative diploid progenitor <it>Aegilops speltoides </it>in hexaploid (genomic formula, BBAADD) and tetraploid (genomic formula, BBAA) wheats as well as their diploid progenitors. Analysis of the complete BAC_2383A24 nucleotide sequence (113 605 bp) demonstrated that it contains 55.6% TEs, 0.9% subtelomeric tandem repeats (Spelt1), and five genes. LTR retrotransposons are predominant, representing 50.7% of the total nucleotide sequence. Three elements of the <it>gypsy </it>LTR retrotransposon family <it>Fatima </it>make up 47.2% of all the LTR retrotransposons in this BAC. <it>In situ </it>hybridisation of the <it>Fatima</it>_2383A24-3 subclone suggests that individual representatives of the <it>Fatima </it>family contribute to the majority of the B-genome specific FISH pattern for BAC_2383A24. Phylogenetic analysis of various <it>Fatima </it>elements available from databases in combination with the data on their insertion dates demonstrated that the <it>Fatima </it>elements fall into several groups. One of these groups, containing <it>Fatima</it>_2383A24-3, is more specific to the B-genome and proliferated around 0.5-2.5 MYA, prior to allopolyploid wheat formation.</p> <p>Conclusion</p> <p>The B-genome specificity of the <it>gypsy</it>-like <it>Fatima</it>, as determined by FISH, is explained to a great degree by the appearance of a genome-specific element within this family for <it>Ae. speltoides</it>. Moreover, its proliferation mainly occurred in this diploid species before it entered into allopolyploidy.</p> <p>Most likely, this scenario of emergence and proliferation of the genome-specific variants of retroelements, mainly in the diploid species, is characteristic of the evolution of all three genomes of hexaploid wheat.</p

    Isolation and sequence analysis of the wheat B genome subtelomeric DNA

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    <p>Abstract</p> <p>Background</p> <p>Telomeric and subtelomeric regions are essential for genome stability and regular chromosome replication. In this work, we have characterized the wheat BAC (bacterial artificial chromosome) clones containing Spelt1 and Spelt52 sequences, which belong to the subtelomeric repeats of the B/G genomes of wheats and <it>Aegilops </it>species from the section <it>Sitopsis</it>.</p> <p>Results</p> <p>The BAC library from <it>Triticum aestivum </it>cv. Renan was screened using Spelt1 and Spelt52 as probes. Nine positive clones were isolated; of them, clone 2050O8 was localized mainly to the distal parts of wheat chromosomes by <it>in situ </it>hybridization. The distribution of the other clones indicated the presence of different types of repetitive sequences in BACs. Use of different approaches allowed us to prove that seven of the nine isolated clones belonged to the subtelomeric chromosomal regions. Clone 2050O8 was sequenced and its sequence of 119 737 bp was annotated. It is composed of 33% transposable elements (TEs), 8.2% Spelt52 (namely, the subfamily Spelt52.2) and five non-TE-related genes. DNA transposons are predominant, making up 24.6% of the entire BAC clone, whereas retroelements account for 8.4% of the clone length. The full-length CACTA transposon <it>Caspar </it>covers 11 666 bp, encoding a transposase and CTG-2 proteins, and this transposon accounts for 40% of the DNA transposons. The <it>in situ </it>hybridization data for 2050O8 derived subclones in combination with the BLAST search against wheat mapped ESTs (expressed sequence tags) suggest that clone 2050O8 is located in the terminal bin 4BL-10 (0.95-1.0). Additionally, four of the predicted 2050O8 genes showed significant homology to four putative orthologous rice genes in the distal part of rice chromosome 3S and confirm the synteny to wheat 4BL.</p> <p>Conclusion</p> <p>Satellite DNA sequences from the subtelomeric regions of diploid wheat progenitor can be used for selecting the BAC clones from the corresponding regions of hexaploid wheat chromosomes. It has been demonstrated for the first time that Spelt52 sequences were involved in the evolution of terminal regions of common wheat chromosomes. Our research provides new insights into the microcollinearity in the terminal regions of wheat chromosomes 4BL and rice chromosome 3S.</p

    Economic Migration in Central Siberia and Ethnic Conflict Risks (Based on Krasnoyarsk Krai Analysis)

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    Migration, be it free or forced, is an essential prerequisite of the dynamic development of many territories, Krasnoyarsk Krai inclusive. The territory of the region is irregularly and poorly populated: 84% of inhabitants are concentrated in the south of the region, in the territory comprising only 10% of the regional territory. Under the circumstances Krasnoyarsk Krai needs an increased flow of migrants for the participation in economic development of unpopulated areas of Krai. But on the other hand, economic need in migrants becomes the reason of the ethnic conflicts risks increase in Central Siberia through creation of various negative myths on migrants. The experts report an increase in social tension between migrants and host parties in the Siberian regions of the Russian Federation. The interrelations inside the social medium and cultural contacts are in many respects determinant for the economic development of the region because the main actors of the economics are people. Keywords: economic migration, tolerance index, Siberia, Krasnoyarsk Krai JEL Classifications: D8, R1, Z

    The Influence of Neurotrophic Factors BDNF and GDNF Overexpression on the Functional State of Mice and Their Adaptation to Audiogenic Seizures.

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    peer reviewedThe high prevalence of diagnosed cases of severe neurological disorders, a significant proportion of which are epilepsy, contributes to a high level of mortality and disability in the population. Neurotrophic factors BDNF and GNDF are considered promising agents aimed at increasing the central nervous system's adaptive potential for the development of the epileptiform activity. Despite the pronounced neuroprotective and anticonvulsant potential, an appropriate way to stimulate these endogenous signaling molecules with minimal risk of side effects remains an open question. Herein, we assessed the safety of gene therapy using original adeno-associated viral constructs carrying the genes of neurotrophic factors BDNF and GDNF in the early postnatal period of development of experimental animals. The intraventricular injection of AAV-Syn-BDNF-eGFP and AAV-Syn-GDNF-eGFP viral constructs into newborn mice was found to provide persistent overexpression of target genes in the hippocampus and cerebral cortex in vivo for four weeks after injection. The application of viral constructs has a multidirectional effect on the weight and body length characteristics of mice in the early postnatal period; however, it ensures the animals' resistance to the development of seizure activity under audiogenic stimulation in the late postnatal period and preserves basic behavioral reactions, emotional status, as well as the mnestic and cognitive abilities of mice after simulated stress. Our results demonstrated the safety of using the AAV-Syn-BDNF-eGFP and AAV-Syn-GDNF-eGFP viral constructs in vivo, which indicates the expediency of further testing the constructs as therapeutic anticonvulsants

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