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Transfer RNA-derived small RNAs in plants

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Science China(Life Sciences) 2018年第2期61卷 155-161页

作者： Lei Zhu david w.ow Zhicheng Dong Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China University of Chinese Academy of Sciences Beijing 100049 China

Rather than random degradation products, the 18 to 40 nucleotides(nt) transfer RNA-derived small RNAs(tsRNAs) are RNA species generated specifically from pre-RNAs or mature tRNAs in archaea, bacteria and eukaryotes. Recent studies from animal systems have shown that tsRNAs are important non-coding RNAs that regulate gene expression at the transcriptional and/or post-transcriptional levels. They are involved in various biological processes, such as cell proliferation, tumor genesis, stress response and intergenerational epigenetic inheritance. In this review, we will summarize the discovery, biogenesis, and function of tsRNAs in higher plants. In addition, analysis on tsRNAs from lower plants is shown.

关键词： tRNA derived-small RNAs tsRNAs biogenesis plant

An Open-Source System for In Planta Gene Stacking by Bxbl and Cre Recombinases

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Molecular Plant 2014年第12期7卷 1756-1765页

作者： Lili Hou Yuan-Yeu Yau Junjie wei Zhiguo Han Zhicheng Dong david w. ow Plant Gene Engineering Center South China Agricultural Plant Molecular Analysis and Genetic Improvement Key Laboratory SouthChina Botanical Garden Chinese Academy of Sciences 723 Xingke Road Guangzhou 510650 China University of Chinese Academy of Sciences 19 Yuquan Road Beijing 100049 China Former Affiliation Plant Gene Expression Center USDA-ARS & Plant & Microbial Biology University of California-Berkeley 800Buchanan St. Albany CA 94710 USA

The rapid development of crops with multiple transgenic traits arouses the need for an efficient system for creating stacked cultivars. Most major crops rely on classical breeding to introgress the transgene from a laboratory variety to the numerous cultivars adapted to different growing regions. Even with vegetative propagated crops, genetic crosses are conducted during varietal improvement prior to vegetative cloning. The probability to assort the ＇x＇ number of transgenic loci into a single genome may seem trivial, （~）x for a diploid species, but given the ＇y＇ number of other nontransgenic traits that breeders also need to assemble into the same genome, the （~）~＊y probability for a ＇breeding stack＇ could quickly make the line conversion process unmanageable. Adding new transgenes onto existing transgenic varieties without creating a new segregating locus would require site-specific integration of new DNA at the existing transgenic locus. Here, we tested a recombinase-mediated gene-stacking scheme in tobacco. Sequential site-specific inte- gration was mediated by the mycobacteriophage Bxbl integrase-catalyzed recombination between attP and attB sites. Transgenic DNA no longer needed after integration was excised by Cre recombinase-mediated recombination of Iox sites. Site-specific integration occurred in -10% of the integration events, with half of those events usable as substrates for a next round of gene stacking. Among the site-specific integrants, however, a third experienced gene silencing. Overall, precise structure and reproducible expression of the sequentially added triple traits were obtained at an overall rate of -3% of the transformed clones--a workable frequency for the development of commercial cultivars. Moreover, since nei- ther the Bxbl-att nor the Cre-lox system is under patent, there is freedom to operate,

关键词： transgenesis site-specific recombination integrase gene targeting transgene expression.

Reduction of Cd in Rice through Expression of OXS3-like Gene Fragments

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Molecular Plant 2016年第2期9卷 301-304页

作者： wang, Changhu Guo, weili Ye, Shan wei, Pengcheng ow, david w. Chinese Acad Sci South China Bot Garden Plant Gene Engn Ctr 723 Xingke Rd Guangzhou 510650 Guangdong Peoples R China Anhui Acad Agr Sci Inst Rice Res Hefei 230031 Peoples R China

Dear Editor,Cadmium （Cd） is a toxic heavy metal and carcinogen, and its en- try into the food chain has serious effects on food security and public health （Uraguchi et al., 2011）. As rice is a staple food crop for half of the world＇s population, Cd in rice grain has become a major source of dietary Cd for this part of the world.

关键词： become effective decided

Making bridges between preclinical and clinical insights into age-related cognitive decline

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Neural Regeneration Research 2025年第8期20卷 2321-2322页

作者： david VC Brito Clévio Nóbrega Algarve Biomedical Center-Research Institute(ABC-RI) Campus GambelasFaroPortugal Algarve Biomedical Center-(ABC) Campus GambelasFaroPortugal Faculty of Medicine and Biomedical Sciences(FMCB) University of AlgarveGambelas CampusFaroPortugal

with people living longer,the societal impact of age-related cognitive decline is becoming more pronounced(Crimmins,2015).Thus,it is increasingly important to comprehend the cognitive shifts linked to aging-whether th... 详细信息

关键词： bridges becoming insight

women in visual neural regeneration research

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Neural Regeneration Research 2025年第2期20卷 489-490页

作者： Tonia S.Rex david J.Calkins Vanderbilt Eye Institute Vanderbilt University Medical CenterNashvilleTNUSA

The year 2024 marks the 60^(th)anniversary of Title IX and 25 years since the New York Times revealed bias against female faculty members at the Massachusetts Institute of *** take an opportunity here to examine the state of gender bias in a relatively new yet already prominent field,neural regeneration in the visual system,for which there is a well-defined context useful for this *** National Eye Institute(NEI)provided the first round of research funding for its Audacious Goals Initiative(AGI)on visual neural regeneration in 2013 and the last round in ***,we focus on this *** sources included PubMed,the National Science Foundation(NSF),the NEI,the Blue Ridge Institute for Medical Research and data from the major professional organization for eye and vision research,the Association for Research in Vision and Ophthalmology(ARVO).

关键词： neural visual Times

Competition and the evolution of imperfect mimicry

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Current Zoology 2012年第4期58卷 608-619页

作者： david w. PFENNIG david w. KIKUCHI Department of Biology University of North Carolina Chapel Hill NC 27599-3280 USA

Mimicry is widely used to exemplify natural selection＇s power in promoting adaptation. Nonetheless, it has become increasingly clear that mimicry is frequently imprecise. Indeed, the phenotypic match is often poor between mimics and models in many Batesian mimicry complexes and among co-mimics in many Mtillerian mimicry complexes. Here, we consider whether such imperfect mimicry represents an evolutionary compromise between predator-mediated selection favoring mimetic conver- gence on the one hand and competitively mediated selection favoring divergence on the other hand. Specifically, for mimicry to be effective, mimics and their models/co-mimics should occur together. Yet, co-occurring species that are phenotypically similar often compete for resources, successful reproduction, or both. As an adaptive response to minimize such costly interactions, in-teracting species may diverge phenotypically through an evolutionary process known as character displacement. Such divergence between mimics and their models/co-mimics may thereby result in imperfect mimicry. we review the various ways in which character displacement could promote imprecise mimicry, describe the conditions under which this process may be especially likely to produce imperfect mimicry, examine a possible case study, and discuss avenues for future research. Generally, character displacement may play an underappreciated role in fostering inexact mimicry .

关键词： Batesian mimicry Character displacement Hybridization MtUlerian mimicry Reproductive interference Selectivetrade-off

A Batesian mimic and its model share color production mechanisms

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Current Zoology 2012年第4期58卷 658-667页

作者： david w. KIKUCHI david w. PFENNIG Department of Biology University of North Carolina at Chapel Hill Chapel Hill NC 27599-3280 USA

Batesian mimics are harmless prey species that resemble dangerous ones （models）, and thus receive protection from predators. How such adaptive resemblances evolve is a classical problem in evolutionary biology. Mimicry is typically thought to be difficult to evolve, especially if the model and mimic produce the convergent phenotype through different proximate mecha- nisms. However, mimicry may evolve more readily if mimic and model share similar pathways for producing the convergent phenotype. In such cases, these pathways can be co-opted in ancestral mimic populations to produce high-fidelity mimicry with- out the need for major evolutionary innovations. Here, we show that a Batesian mimic, the scarlet kingsnake Larnpropeltis elap-soides, produces its coloration using the same physiological mechanisms as does its model, the eastern coral snake Micrurus fulvius. Therefore, precise color mimicry may have been able to evolve easily in this system. Generally, we know relatively little about the proximate mechanisms underlying mimicry .

关键词： Adaptation Coloration Convergent evolution Pteridine Pigment

A Review of the Taxonomy and Palaeoecology of the Anurognathidae(Reptilia,Pterosauria)

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Acta Geologica Sinica(English Edition) 2020年第5期94卷 1676-1692页

作者： david w.E.HONE School of Biological and Chemical Sciences Queen Mary University of LondonLondonE14NSUK

The anurognathids are an enigmatic and distinctive clade of small,non-pterodactyloid pterosaurs with an unusual combination of anatomical traits in the head,neck,wings and *** are known from very limited remains and few have been described in detail,and as a result,much of their biology remains *** is despite their importance as potentially one of the earliest branches of pterosaur evolution or even lying close to the origins of *** review covers the taxonomy and palaeoecology of the anurognathids,which remain an interesting branch of pterosaurian evolution.

关键词： non-pterodactyloid palaeobiology flight Ornithodira

Beyond the burn: Studies on the physiological effects of flamethrowers during world war Ⅱ

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Military Medical Research 2020年第3期7卷 303-311页

作者： david w.Van wyck 4/3 SFG(A)Bldg Z-4157 South Post Rd Fort BraggNC 28310USA

Flamethrowers are widely considered one of warfare’s most controversial weapons and are capable of inflicting gruesome physical injuries and intense psychological *** being the last of the major combatants in world warⅡ(wwⅡ)to develop them,the *** quickly became the most frequent and adept operator of portable *** gave the *** ample opportunity to observe the effects of flamethrowers on enemy ***,while most people in modern times would consider immolation by flamethrower to be an unnecessarily painful and inhumane way to inflict casualties,immolation was,at one point during wwⅡ,referred to as"mercy killing"by the *** warfare Service(CwS).This mischaracterization arose from a series of firsthand accounts describing what were believed to be quick,painless,and unmarred deaths,as well as from a poor and incomplete understanding of flamethrower *** a result,indirect mechanisms such as hypoxia and carbon monoxide poisoning were generally absent from accounts of the flamethrower’s fatal *** was not until several years after flamethrowers were introduced to the frontlines that the CwS and National Defense Research Committee(NDRC)conducted a series of tests to better understand the physiological and toxicological effects of *** article examines how the initial absence of scientific data on the physiologic effects of flamethrowers led to an inaccurate understanding of their lethality,and bizarre claims that one of history’s most horrific instruments of war was considered one of the more"humane"weapons on the battlefield.

关键词： Flamethrower Burns Carbon monoxide Asphyxiation Hypoxia Chemical warfare