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61.
用随机引物扩增多态DNA(RAPD)技术对三种不同组合:小麦(Triticum aestivum)( )簇毛麦(Haynaldia villosa);小麦( )羊草(Leymus chinensis)和小麦( )高冰草(Agropyron elongatum)的属间不对称杂种进行分子鉴定,不同杂种植株的基因组经随机引物扩增后,均出现双亲的多态特异产物,证实它们含有双亲的基因组。将引物OPJ-12扩增的高冰草多态特异产物(分子量为0.77bp的DNA片段)分离纯化并标记作探针,用Southern杂交证明了小麦( )高冰草杂种经OPJ-12扩增的0.77kbp特异片段与高冰草这一片段具有同源性。本文结果证明,RAPD技术可作为小麦属间不对称体细胞杂种的一种快速、简便、有效的分子鉴定方法。 相似文献
62.
Three-dimensional quantitative structure–activity relationship (3D-QSAR) studies were performed on a series of substituted 1,4-dihydroindeno[1,2-c]pyrazoles inhibitors, using molecular docking and comparative molecular field analysis (CoMFA). The docking results from GOLD 3.0.1 provide a reliable conformational alignment scheme for the 3D-QSAR model. Based on the docking conformations and alignments, highly predictive CoMFA model was built with cross-validated q 2 value of 0.534 and non-cross-validated partial least-squares analysis with the optimum components of six showed a conventional r 2 value of 0.911. The predictive ability of this model was validated by the testing set with a conventional r 2 value of 0.812. Based on the docking and CoMFA, we have identified some key features of the 1,4-dihydroindeno[1,2-c]pyrazoles derivatives that are responsible for checkpoint kinase 1 inhibitory activity. The analyses may be used to design more potent 1,4-dihydroindeno[1,2-c]pyrazoles derivatives and predict their activity prior to synthesis. 相似文献
63.
64.
Benjamin Chun-Kit Tong Aston Jiaxi Wu Min Li King-Ho Cheung 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2018,1865(11):1745-1760
Alzheimer's disease (AD) is the most common type of dementia and is characterized by the accumulation of amyloid (Aβ) plaques and neurofibrillary tangles in the brain. Much attention has been given to develop AD treatments based on the amyloid cascade hypothesis; however, none of these drugs had good efficacy at improving cognitive functions in AD patients suggesting that Aβ might not be the disease origin. Thus, there are urgent needs for the development of new therapies that target on the proximal cause of AD. Cellular calcium (Ca2+) signals regulate important facets of neuronal physiology. An increasing body of evidence suggests that age-related dysregulation of neuronal Ca2+ homeostasis may play a proximal role in the pathogenesis of AD as disrupted Ca2+ could induce synaptic deficits and promote the accumulation of Aβ plaques and neurofibrillary tangles. Given that Ca2+ disruption is ubiquitously involved in all AD pathologies, it is likely that using chemical agents or small molecules specific to Ca2+ channels or handling proteins on the plasma membrane and membranes of intracellular organelles to correct neuronal Ca2+ dysregulation could open up a new approach to AD prevention and treatment. This review summarizes current knowledge on the molecular mechanisms linking Ca2+ dysregulation with AD pathologies and discusses the possibility of correcting neuronal Ca2+ disruption as a therapeutic approach for AD. 相似文献
65.
Jun Feng Weixia Gao Yanyan Gu Wei Zhang Mingfeng Cao Cunjiang Song Peng Zhang Min Sun Chao Yang Shufang Wang 《Applied microbiology and biotechnology》2014,98(14):6397-6407
Poly-γ-glutamic acid (γ-PGA) is an important biopolymer with greatly potential in industrial and medical applications. In the present study, we constructed a metabolically engineered glutamate-independent Bacillus amyloliquefaciens LL3 strain with considerable γ-PGA production, which was carried out by single, double, and triple markerless deletions of three degradation genes pgdS, ggt, and cwlO. The highest γ-PGA production (7.12 g/L) was obtained from the pgdS and cwlO double-deletion strain NK-pc, which was 93 % higher than that of wild-type LL3 strain (3.69 g/L). The triple-gene-deletion strain NK-pgc showed a 28 % decrease in γ-PGA production, leading to a yield of 2.69 g/L. Furthermore, the cell morphologies of the mutant strains were also characterized. The cell length of cwlO deletion strains NK-c and NK-pc was shorter than that of the wild-type strain, while the ggt deletion strains NK-g, NK-pg, NK-gc, and NK-pgc showed longer cell lengths. This is the first report concerning the markerless deletion of γ-PGA degradation genes to improve γ-PGA production in a glutamate-independent strain and the first observation that γ-glutamyltranspeptidase (encoded by ggt) could be involved in the inhibition of cell elongation. 相似文献
66.
67.
Lineage-specific evolution and gene flow in Listeria monocytogenes are independent of bacteriophages
Roxana Zamudio Richard D. Haigh Joseph D. Ralph Megan De Ste Croix Taurai Tasara Katrin Zurfluh Min Jung Kwun Andrew D. Millard Stephen D. Bentley Nicholas J. Croucher Roger Stephan Marco R. Oggioni 《Environmental microbiology》2020,22(12):5058-5072
Listeria monocytogenes is a foodborne pathogen causing systemic infection with high mortality. To allow efficient tracking of outbreaks a clear definition of the genomic signature of a cluster of related isolates is required, but lineage-specific characteristics call for a more detailed understanding of evolution. In our work, we used core genome MLST (cgMLST) to identify new outbreaks combined to core genome SNP analysis to characterize the population structure and gene flow between lineages. Whilst analysing differences between the four lineages of L. monocytogenes we have detected differences in the recombination rate, and interestingly also divergence in the SNP differences between sub-lineages. In addition, the exchange of core genome variation between the lineages exhibited a distinct pattern, with lineage III being the best donor for horizontal gene transfer. Whilst attempting to link bacteriophage-mediated transduction to observed gene transfer, we found an inverse correlation between phage presence in a lineage and the extent of recombination. Irrespective of the profound differences in recombination rates observed between sub-lineages and lineages, we found that the previously proposed cut-off of 10 allelic differences in cgMLST can be still considered valid for the definition of a foodborne outbreak cluster of L. monocytogenes. 相似文献
68.
茶园间作柑桔杨梅或吊瓜对叶蝉及蜘蛛类群数量和空间格局的影响 总被引:4,自引:0,他引:4
为评价茶园间作几种常见经济作物对重要害虫假眼小绿叶蝉及其主要天敌蜘蛛类群数量和空间格局的影响,遂选乌牛早品种纯茶园、乌牛早分别与柑桔、杨梅和吊瓜的间作茶园、以及安吉白茶与吊瓜间作茶园,2007年9月上旬—2008年12月下旬,每旬1次调查茶丛上、中、下层叶蝉和各种蜘蛛的数量。结果表明:(1)与纯茶园相比,间作茶园叶蝉种群数量和蜘蛛类群个体数量显著地增加,间作茶园蜘蛛种数显著地增加;(2)间作茶园茶丛上、中、下层叶蝉、蜘蛛个体数量分布明显区别于纯茶园茶丛上、中、下层叶蝉、蜘蛛个体数量分布;(3)茶丛上层的嫩梢是制作高档茶的原料,而纯茶园茶丛上层叶蝉虫口百分率为54.16%,间作茶园茶丛上层叶蝉虫口百分率皆减小,并且叶蝉高峰期间蜘蛛的跟随效应增强;(4)间作增加了经济收入并减少了防治次数。认为:(1)间作可在一定程度上调控叶蝉种群、蜘蛛类群的数量和空间格局;(2)间作可减轻叶蝉为害造成的产值损失,增强了茶园群落对于叶蝉的自然控制潜能。 相似文献
69.
本研究采用温室盆栽试验,利用丛枝菌根(AM)真菌摩西管柄囊霉Funneliformis mosseae进行接种试验,研究了在Cd胁迫下(0、5、15和30mg/kg)接种AM真菌对高羊茅Festuca elata ‘Crossfire II’的生物量、防御酶活性、磷和镉(Cd)含量的影响。结果表明,随着Cd浓度的增加,高羊茅的菌根侵染率和菌根相对依赖性有所增加。接种AM真菌改善了磷从植株根系向地上部的转运,有助于植株在地上部积累更多的磷。此外,AM真菌和Cd胁迫对高羊茅植株抗氧化酶活性都有显著影响,在镉胁迫下,与未接种植株相比,接种AM真菌显著提高了植株的过氧化氢酶活性,而显著降低了植株的丙二醛含量。与未接种植株相比,接种摩西管柄囊霉显著提高了寄主植物对Cd的富集能力,有利于重金属在根部的积累,同时降低了地上部的Cd含量。本研究表明,高羊茅-丛枝菌根共生体在Cd污染土壤的修复中具有潜在应用价值。 相似文献
70.
Kimura H Kwan KM Zhang Z Deng JM Darnay BG Behringer RR Nakamura T de Crombrugghe B Akiyama H 《PloS one》2008,3(9):e3174