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221.
生命形成的过程极其漫长, 经历了地球系统复杂的沧海桑田变化。当前人类所观察到的物种分布格局的形成除了由物种本身特征决定外, 还受到环境变化、人类活动以及各种随机事件的影响。受限于实验条件、时间、经费、人力等诸多因素, 我们尚无法完整地观察并记录到物种多样性形成的全过程, 只能通过片段化数据来推测该过程。信息科学中包括数值模拟在内的仿真技术以其高效、可控及全过程记录等优势, 能从某种程度上解决物种多样性格局形成过程中的部分数据黑箱问题。本文介绍了数值模拟的概念和工作原理及在物种多样性研究中应用的特点, 列举了物种生态位、扩散模式、种间互作及物种分布应对气候变化等方面的数值模拟研究, 基于已有研究系统地介绍了如何综合上述数值模拟研究构建虚拟物种、气候和场景来解释物种多样性的形成与维持机制, 并阐述了数值模拟在物种多样性研究中的优缺点及应用前景。 相似文献
222.
为快速鉴定糜子(Panicum miliaceum)资源, 建立分子标记检测平台, 以272份山西糜子核心种质为研究材料, 利用85对简单重复序列(SSR)引物, 应用ID Analysis 4.0软件, 构建DNA分子身份证。结果表明, 对85对SSR引物进行筛选, 发现20对引物组合(RYW67、RYW53、RYW37、RYW65、RYW62、RYW77、RYW5、RYW49、RYW84、RYW19、RYW11、RYW40、RYW54、RYW28、RYW31、RYW7、RYW16、RYW8、RYW9和RYW18)可区分272份材料。共检测到等位变异(Na) 60个, 平均每个位点检出3个; Shannon多样性指数(I)为0.957 8 (RYW16)-1.096 7 (RYW5), 平均值为1.055 2; 多态性信息含量(PIC)为0.604 4 (RYW77)-0.753 0 (RYW37), 平均值为0.692 1。利用20对引物构建山西糜子核心种质的字符串、条形码和二维码DNA分子身份证, 可为种质身份标识和溯源提供实践路径。 相似文献
223.
Mariann M. Gabrawy Reyhan Westbrook Austin King Nick Khosravian Neeraj Ochaney Tagide DeCarvalho Qinchuan Wang Yuqiong Yu Qiao Huang Adam Said Michael Abadir Cissy Zhang Pratik Khare Jennifer E. Fairman Anne Le Ginger L. Milne Fernando J. Vonhoff Jeremy D. Walston Peter M. Abadir 《Aging cell》2024,23(4):e14102
Tryptophan catabolism is highly conserved and generates important bioactive metabolites, including kynurenines, and in some animals, NAD+. Aging and inflammation are associated with increased levels of kynurenine pathway (KP) metabolites and depleted NAD+, factors which are implicated as contributors to frailty and morbidity. Contrastingly, KP suppression and NAD+ supplementation are associated with increased life span in some animals. Here, we used DGRP_229 Drosophila to elucidate the effects of KP elevation, KP suppression, and NAD+ supplementation on physical performance and survivorship. Flies were chronically fed kynurenines, KP inhibitors, NAD+ precursors, or a combination of KP inhibitors with NAD+ precursors. Flies with elevated kynurenines had reduced climbing speed, endurance, and life span. Treatment with a combination of KP inhibitors and NAD+ precursors preserved physical function and synergistically increased maximum life span. We conclude that KP flux can regulate health span and life span in Drosophila and that targeting KP and NAD+ metabolism can synergistically increase life span. 相似文献
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松辽盆地阿尔必期微体浮游植物新属种 总被引:1,自引:3,他引:1
该文描述了松辽盆地中白垩世阿尔必期泉头组三段的微体浮游植物化石1新属7新种,隶属于微咸水沟鞭藻类2属5新种(含4新亚种),淡水绿藻1属1种和疑源类1新属1新种。并对沟鞭藻 Ngktericysta Bint,1986进行了修订。 相似文献
226.
乔传令 《分子细胞生物学报》1992,(2)
本文用亲和层析法从Calderobacteriumhydrogenophilum(极端耐热细菌)中分离得到纯的耐热蛋白质延长因子。测得其相对的分子量为51000。该蛋白质对热极其稳定,从膜过滤分析法测定EF-Tu 的活性可知,在80℃加热5 min后,原活性仅仅失去50%。Ouchterlony双向免疫扩散的结果表明,该蛋白延长因子与E.coli 延长因子有着抗原的相似性。而且该因子只含一个半胱氨酸残基,其位置在半胱氨酸81,即肽段T_(13)。Southern 杂交试验的结果显示出C.hydrogenophilum 的染色体DNA 中可能有两个基因编码同一蛋白。 相似文献
227.
Yanan Liu Tongjun Sun Yulin Sun Yanjun Zhang Ana Radoji
i Yuli Ding Hainan Tian Xingchuan Huang Jiameng Lan Siyu Chen Alberto Ruiz Orduna Kewei Zhang Reinhard Jetter Xin Li Yuelin Zhang 《The Plant cell》2020,32(12):4002
The plant defense hormone salicylic acid (SA) is perceived by two classes of receptors, NPR1 and NPR3/NPR4. They function in two parallel pathways to regulate SA-induced defense gene expression. To better understand the roles of the SA receptors in plant defense, we systematically analyzed their contributions to different aspects of Arabidopsis (Arabidopsis thaliana) plant immunity using the SA-insensitive npr1-1 npr4-4D double mutant. We found that perception of SA by NPR1 and NPR4 is required for activation of N-hydroxypipecolic acid biosynthesis, which is essential for inducing systemic acquired resistance. In addition, both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) are severely compromised in the npr1-1 npr4-4D double mutant. Interestingly, the PTI and ETI attenuation in npr1-1 npr4-4D is more dramatic compared with the SA-induction deficient2-1 (sid2-1) mutant, suggesting that the perception of residual levels of SA in sid2-1 also contributes to immunity. Furthermore, NPR1 and NPR4 are involved in positive feedback amplification of SA biosynthesis and regulation of SA homeostasis through modifications including 5-hydroxylation and glycosylation. Thus, the SA receptors NPR1 and NPR4 play broad roles in plant immunity. 相似文献
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229.
Xiao Lei Na Ma Yanjie Liang Junyan Liu Pei Zhang Yanan Han Wei Chen Lehui Du Baolin Qu 《Journal of cellular and molecular medicine》2020,24(18):11018-11023
Radiotherapy is one of the most important treatments for chest tumours. Although there are plenty of strategies to prevent damage to normal lung tissues, it cannot be avoided with the emergence of radiation‐induced lung injury. The purpose of this study was to investigate the potential radioprotective effects of glucosamine, which exerted anti‐inflammatory activity in joint inflammation. In this study, we found glucosamine relieved inflammatory response and structural damages in lung tissues after radiation via HE staining. Then, we detected the level of epithelial‐mesenchymal transition marker in vitro and in vivo, which we could clearly observe that glucosamine treatment inhibited epithelial‐mesenchymal transition. Besides, we found glucosamine could inhibit apoptosis and promote proliferation of normal lung epithelial cells in vitro caused by radiation. In conclusion, our data showed that glucosamine alleviated radiation‐induced lung injury via inhibiting epithelial‐mesenchymal transition, which indicated glucosamine could be a novel potential radioprotector for radiation‐induced lung injury. 相似文献
230.