排序方式: 共有76条查询结果,搜索用时 0 毫秒
1.
2.
MtDNA and Y-Chromosome Lineages in the Yakut Population 总被引:1,自引:0,他引:1
Puzyrev V. P. Stepanov V. A. Golubenko M. V. Puzyrev K. V. Maximova N. R. Kharkov V. N. Spiridonova M. G. Nogovitsina A. N. 《Russian Journal of Genetics》2003,39(7):816-822
The structure of female (mtDNA) and male (Y-chromosome haplotypes) lineages in the Yakut population was examined. To determine mtDNA haplotypes, sequencing of hypervariable segment I and typing of haplotype-specific point substitutions in the other parts of the mtDNA molecule were performed. Y haplogroups were identified through typing of biallelic polymorphisms in the nonrecombining part of the chromosome. Haplotypes within haplogroups were analyzed with seven microsatellite loci. Mitochondrial gene pool of Yakuts is mainly represented by the lineages of eastern Eurasian origin (haplogroups A, B, C, D, G, and F). In Yakuts haplogroups C and D showing the total frequency of almost 80% and consisting of 12 and 10 different haplopypes, respectively, were the most frequent and diverse. The total part of the lineages of western Eurasian origin (Caucasoid) was about 6% (4 haplotypes, haplogroups H, J, and U). Most of Y chromosomes in the Yakut population (87%) belonged to haplogroup N3 (HG16), delineated by the T–C substitution at the Tat locus. Chromosomes of haplogroup N3 displayed the presence of 19 microsatellite haplotypes, the most frequent of which encompassed 54% chromosomes of this haplogroup. Median network of haplogroup N3 in Yakuts demonstrated distinct starlike phylogeny. Male lineages of Yakuts were shown to be closest to those of Eastern Evenks. 相似文献
3.
Siela?N.?Maximova Larence?Alemanno Ann?Young Nicole?Ferriere Abdoulaye?Traore Mark?J.?GuiltinanEmail author 《In vitro cellular & developmental biology. Plant》2002,38(3):252-259
Summary The development of efficient tissue culture systems for cacao holds the potential to contribute to the improvement of this
tropical erop by providing a rapid and efficient vegetative propagation system for multiplication of elite genotypes. It may
also find application in facilitation of germplasm movement across quarantine borders, enhancement of germplasm conservation
via cryo-preservation, and development of genetic transformation systems. Somatic embryogenesis using floral tissue explants
was previously the only tissue culture procedure for regeneration of cacao. We report the development of a secondary embryogenesis
system utilizing primary somatic embryo cotyledon explants, which results in up to a 30-fold increase in somatic embryo production
compared to primary somatic embryogenesis. The influence of genotype on the efficiency of the system was evaluated. To understand
the cellular origins and developmental pathways operative in this system, we investigated the morphological changes occurring
over time using light and scanning electron microscopy. While primary embryos arise from clusters of cells forming embryonic
nodules, secondary embryos arise predominantly from the division of single cells, in a pathway reminiscent of zygotic embryogenesis.
These results have important significance to the application of tissue culture to cacao improvement programs. 相似文献
4.
5.
1. Examining male residents of the Russian Far-East, changes in their heart rate structures and temperature variations on the hand surfaces under hypoxic and local cold factor were studied.
2. Reliable differences in statistical and spectral-wave indices of human heart rate and hand surface thermal pattern depending on the level of nonspecific resistance.
3. It is possible to select persons resistant to low temperature and oxygen deficiency by their heart rate responses to hypoxia and local cold impacts. 相似文献
6.
7.
From mutations to mechanisms and dysfunction via computation and mining of protein energy landscapes
Qiao Wanli Akhter Nasrin Fang Xiaowen Maximova Tatiana Plaku Erion Shehu Amarda 《BMC genomics》2018,19(7):671-13
Background
The protein energy landscape underscores the inherent nature of proteins as dynamic molecules interconverting between structures with varying energies. Reconstructing a protein’s energy landscape holds the key to characterizing a protein’s equilibrium conformational dynamics and its relationship to function. Many pathogenic mutations in protein sequences alter the equilibrium dynamics that regulates molecular interactions and thus protein function. In principle, reconstructing energy landscapes of a protein’s healthy and diseased variants is a central step to understanding how mutations impact dynamics, biological mechanisms, and function.Results
Recent computational advances are yielding detailed, sample-based representations of protein energy landscapes. In this paper, we propose and describe two novel methods that leverage computed, sample-based representations of landscapes to reconstruct them and extract from them informative local structures that reveal the underlying organization of an energy landscape. Such structures constitute landscape features that, as we demonstrate here, can be utilized to detect alterations of landscapes upon mutation.Conclusions
The proposed methods detect altered protein energy landscape features in response to sequence mutations. By doing so, the methods allow formulating hypotheses on the impact of mutations on specific biological activities of a protein. This work demonstrates that the availability of energy landscapes of healthy and diseased variants of a protein opens up new avenues to harness the quantitative information embedded in landscapes to summarize mechanisms via which mutations alter protein dynamics to percolate to dysfunction.8.
Jean-Philippe Marelli Siela N. Maximova Karina P. Gramacho Seogchan Kang Mark John Guiltinan 《Tropical plant biology》2009,2(3-4):149-160
The C-biotype of Moniliophthora perniciosa is the causal agent of witches’ broom disease of Theobroma cacao L. While this disease is of major economic importance, the pathogenicity mechanisms and plant responses underlying the disease are difficult to study given the cacao tree’s long life cycle and the limited availability of genetic and genomic resources for this system. The S-biotype of M. perniciosa infects solanaceous hosts, particularly pepper (Capsicum annuum) and tomato (Solanum lycopersicum). These species are much more amenable for performing studies of mechanisms underpinning host-pathogen interactions as compared to cacao. A phylogenetic analysis performed in this study demonstrated that S-biotype strains clustered with C-biotype strains, indicating that these biotypes are not genetically distinct. A comparative analysis demonstrated that disease progression in tomato infected with the S- biotype is similar to that described for cacao infected with the C- biotype. The major symptoms observed in both systems are swelling of the infected shoots and activation and proliferation of axillary meristems. Cellular changes observed in infected tissues correspond to an increase in cell size and numbers of xylem vessels and phloem parenchyma along the infected stem. Observations revealed that fungal colonization is biotrophic during the first phase of infection, with appearance of calcium oxalate crystals in close association with hyphal growth. In summary, despite different host specificity, both biotypes of M. perniciosa exhibit similar disease-related characteristics, indicating a degree of conservation of pathogenicity mechanisms between the two biotypes. 相似文献
9.
Flaviviruses such as West Nile, Japanese encephalitis, and tick-borne encephalitis (TBEV) viruses are important neurotropic human pathogens, causing a devastating and often fatal neuroinfection. Here, we demonstrate that incorporation into the viral genome of a target sequence for cellular microRNAs expressed in the central nervous system (CNS) enables alteration of the neurovirulence of the virus and control of the neuropathogenesis of flavivirus infection. As a model virus for this type of modification, we used a neurovirulent chimeric tick-borne encephalitis/dengue virus (TBEV/DEN4) that contained the structural protein genes of a highly pathogenic TBEV. The inclusion of just a single target copy for a brain tissue-expressed mir-9, mir-124a, mir-128a, mir-218, or let-7c microRNA into the TBEV/DEN4 genome was sufficient to prevent the development of otherwise lethal encephalitis in mice infected intracerebrally with a large dose of virus. Viruses bearing a complementary target for mir-9 or mir-124a were highly restricted in replication in primary neuronal cells, had limited access into the CNS of immunodeficient mice, and retained the ability to induce a strong humoral immune response in monkeys. This work suggests that microRNA targeting to control flavivirus tissue tropism and pathogenesis might represent a rational approach for virus attenuation and vaccine development. 相似文献
10.
EA Dukhanina TI Lukyanova EA Romanova V Guerriero NV Gnuchev GP Georgiev DV Yashin LP Sashchenko 《Cell cycle (Georgetown, Tex.)》2015,14(22):3635-3643
PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4+ and CD8+ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response. 相似文献