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The paper presents the analysis of the frequency, density, and distribution of recombination sites in the male meiosis of the domestic cat (Felis silvestris catus). The study was carried out using immunofluorescent staining of synaptonemal complex (SC) proteins, centromeric proteins and mismatch repair protein MLH1, a reliable marker of crossingover sites. We mapped 2633 sites of crossing over in 1098 individual autosomes. Based on these data, we estimated the total length of the genetic map of the domestic cat to be 2176 centimorgans. Positive correlation between the length of SC and the number of recombination sites common for mammalians was also found in the domestic cat. It was shown that this species was characterized by the highest density of recombination and the lowest interference in mammals. 相似文献
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Methods for site-directed multiple modification of DNA have been developed and used for modification of either one or two strands of plasmid DNA. Plasmid DNAs modified in the region of the tet gene were transformed into Escherichia coli cells and Tet colonies were screened. It was shown that multiple lesions in one DNA strand performed using either N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or sodium bisulfite were effectively repaired in the cell by error-free mechanism. In contrast, modification of two DNA strands led to induction of mutations. The efficiency of mutagenesis in the case of modification of a local region of one DNA strand with sodium bisulfite and modification of the other strand with MNNG was 1.1-7.9%. Mutations were analysed by restriction mapping and sequencing. All of them were G----A transitions. 相似文献
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Russian Journal of Genetics - The study is focused on the analysis of the mechanisms underlying the formation and distribution of repeat clusters in mammalian chromosomes, as exemplified by a group... 相似文献
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Antizyme frameshifting as a functional probe of eukaryotic translational termination 总被引:1,自引:1,他引:0
Karamysheva ZN Karamyshev AL Ito K Yokogawa T Nishikawa K Nakamura Y Matsufuji S 《Nucleic acids research》2003,31(20):5949-5956
Translation termination in eukaryotes is mediated by the release factors eRF1 and eRF3, but mechanisms of the interplay between these factors are not fully understood, due partly to the difficulty of measuring termination on eukaryotic mRNAs. Here, we describe an in vitro system for the assay of termination using competition with programmed frameshifting at the recoding signal of mammalian antizyme. The efficiency of antizyme frameshifting in rabbit reticulocyte lysates was reduced by addition of recombinant rabbit eRF1 and eRF3 in a synergistic manner. Addition of suppressor tRNA to this assay system revealed competition with a third event, stop codon readthrough. Using these assays, we demonstrated that an eRF3 mutation at the GTPase domain repressed termination in a dominant negative fashion probably by binding to eRF1. The effect of the release factors and the suppressor tRNA showed that the stop codon at the antizyme frameshift site is relatively inefficient compared to either the natural termination signals at the end of protein coding sequences or the readthrough signal from a plant virus. The system affords a convenient assay for release factor activity and has provided some novel views of the mechanism of antizyme frameshifting. 相似文献
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Udina I. G. Karamysheva E. E. Turkova S. O. Orlova A. R. Sulimova G. E. 《Russian Journal of Genetics》2003,39(3):306-317
In the herds of Ayrshire and Black Pied cattle breeds of Russian selection, comparative analysis of allelic distribution of BoLA-DRB3 was performed in animal groups with different status of persistent lymphocytosis (PL) caused by the bovine leukemia virus (BLV). Alleles were typed by PCR–RFLP. Different spectra of BoLA-DRB3 alleles mediating susceptibility and resistance to leukemia were detected in the studied breeds. The role of amino acid motives in 1 domain of BoLA-DRB3 antigens was confirmed: ER (in positions 70–71), in resistance to leukemia and VDTY and VDTV (75–78), in susceptibility to leukemia. The nucleotide sequence of allele BoLA-DRB3.2*7with deletion of codon 65, which resulted in the changed conformation of the corresponding antigen molecule, was associated with resistance to PL. Cows of Black Pied and Ayrshire breeds with genotypes coding VDTY/VDTV (RR = 11.67, P = 0,014) and VDTY/VDTY (RR = 4.71, P = 0.022), respectively, were shown to be susceptible to PL. The role of heterozygosity level was demonstrated (estimated by BoLA-DRB3 alleles and by amino acid motives in positions 75–78 of the antigen) as an unspecific factor of resistance to PL. The lowest heterozygosity level by amino acid motives (75–78) was revealed in PL animals, for which sample inbreeding coefficients were detected: F = 0.324 and 0.084 in Ayrshire and Black Pied breeds, respectively. 相似文献
6.
Zakharenko LP Rubtsov NB Karamysheva TV Riabchikova EI Bunkova EIu Kolodina NN Nepomniashchaia TI 《Tsitologiia》2003,45(12):1221-1226
Using light microscopy, we have shown that chlamydia and/or chlamydia-like microorganisms are registered in 20-25% of the healthy part of human population, whereas in patients of the same age with gynecological problems these were found in 40-50%. Commonly, the infection was slightly manifested (less than 5% of cells are infected). These results were confirmed in four months but only in heavily infected patients. The light microscope data are confirmed by observations with electron microscopy, and by FISH hybridization of the total chlamydial DNA on cytological preparations with chlamydial inclusions. In some cases, microcolonies revealed by FISH hybridization occupied the majority of the cytoplasm volume. Occasionally, the DNA material was found on the nuclear surface. It seems likely that in heavily infected cells chlamydia are able to penetrate into the perinucular space. 相似文献
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N. B. Rubtsov T. V. Karamysheva A. S. Bogdanov T. V. Likhoshvay I. V. Kartavtseva 《Russian Journal of Genetics》2011,47(9):1096-1110
The homology of DNA of C-positive centromeric regions of chromosomes in wood mice of the genus Sylvaemus (S. uralensis, S. fulvipectus, S. sylvaticus, S. flavicollis, and S. ponticus) was estimated for the first time. DNA probes were generated by microdissection from the centromeric regions of individual
autosomes of each species, and their fluorescence in situ hybridization (FISH) with metaphase chromosomes of representatives
of all studied wood mouse species was carried out. Unlike in the chromosomal forms and races of S. uralensis, changes in the DNA composition of the chromosomal centromeric regions in the wood mouse species of the genus Sylvaemus (including closely related S. flavicollis and S. ponticus) are both quantitative and qualitative. The patterns of FISH signals after in situ hybridization of the microdissection DNA
probes with chromosomes of the species involved in the study demonstrate significant differences between C-positive regions
of wood mouse chromosomes in the copy number and the level of homology of repetitive sequences as well as in the localization
of homologous repetitive sequences. It was shown that C-positive regions of wood mouse chromosomes can contain both homologous
and distinct sets of repetitive sequences. Regions enriched with homologous repeats were detected either directly in C-positive
regions of individual chromosomes or only on the short arms of acrocentrics, or at the boundary of C-positive and C-negative
regions. 相似文献
10.
Gizatullina ZZ Gaynutdinov TM Svoboda H Jerzembek D Knabe A Vielhaber S Malesevic M Heinze HJ Fischer G Striggow F Gellerich FN 《Mitochondrion》2011,11(3):421-429
We studied the functional properties of isolated brain mitochondria (BM) prepared from total rat brain (BM(total)) or from cerebral subregions under basal and Ca(2+) overload conditions in order to evaluate the effects of cyclosporine A (CsA) in a regiospecific manner. CsA-induced effects were compared with those of two derivatives-the none-immunosuppressive [O-(NH(2)(CH2)(5)NHC(O)CH(2))-D-Ser](8)-CsA (Cs9) and its congener, the immunosuppressive [D-Ser](8)-CsA. The glutamate/malate-dependent state 3 respiration of mitochondria (state 3(glu/mal)) differed in region-specific manner (cortex > striatum = cerebellum > substantia nigra > hippocampus), but was significantly increased by 1μM CsA (+21±5%) in all regions. Ca(2+) overload induced by addition of 20μM Ca(2+) caused a significant decrease of state 3(glu/mal) (-45 to -55%) which was almost completely prevented in the presence of 1μM CsA, 1μM Cs9 or 1μM [D-Ser](8)-CsA. Mitochondrial Ca(2+) accumulation thresholds linked to permeability transition (PT) as well as the rate and completeness of mitochondrial Ca(2+) accumulation differed between different brain regions. For the first time, we provide a detailed, regiospecific analysis of Ca(2+)-dependent properties of brain mitochondria. Regardless of their immunosuppressive impact, CsA and its analogues improved mitochondrial functional properties under control conditions. They also preserved brain mitochondria against Ca(2+) overload-mediated PT and functional impairments. Since Cs9 does not mediate immunosuppression, it might be used as a more specific PT inhibitor than CsA. 相似文献