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11.
采用硅胶柱层析法对黄连木叶粗多酚进行纯化,并且对纯化后的多酚、单宁、黄酮组分进行测定。结果表明,纯化产物中的多酚、单宁、黄酮含量分别为1.0125g当量没食子酸每克样品、0.8600g当量单宁酸每克样品和0.1453g当量芦丁每克样品。与粗多酚相比,多酚含量提高了20.54%,单宁含量提高了13.53%,黄酮含量提高了12.03%。采用DPPH自由基清除法、FRAP总抗氧化法对纯化产物进行体外抗氧化活性检测。同时,以秀丽隐杆线虫(Caenorhabditiselegans)为模式动物检测纯化产物对胡桃醌诱导线虫体内活性氧(ROS)的抑制效应和对线虫存活率的影响。结果表明,黄连木多酚纯化产物体外抗氧活性强于黄连木叶粗多酚,强于维生素C,但稍逊于纯茶多酚;且能显著提高线虫的存活率和降低线虫细胞内ROS浓度。以上结果说明黄连木叶多酚是很好的天然抗氧化剂,具有在食品、医药、化妆品等领域广泛应用的潜力。 相似文献
12.
基于靶点的体外药物筛选操作相对简单,成本较低,但是由于药物在体内的作用并不仅仅取决于其与靶点的作用程度,吸收、分布、代谢、排泄特征和毒性均会对早期先导物能否进入临床使用产生极大的影响,因此,药物的体内筛选受到重视。本文重点综述了秀丽隐杆线虫(C.elegans)在抗衰老、抗感染药物筛选中的应用情况。秀丽隐杆线虫结构简单、易于培养和可实现高通量筛选,在未来的药物筛选中必将发挥更重要的作用。 相似文献
13.
《Cell cycle (Georgetown, Tex.)》2013,12(14):2585-2586
Comment on: Jensen M, et al. Cell 2012; 149:173-87. 相似文献
14.
太空飞行所致的肌萎缩和重力感知的分子机制至今尚不清楚.研究太空飞行对秀丽隐杆线虫(C.elegans)体壁肌细胞结构和功能的影响.经过近15天太空飞行后对其生存率和运动能力进行了观察,并检测了5个重要的肌相关基因的表达和3种蛋白质含量.太空研究是在动物的整体水平进行的,而不是就单个细胞的研究.经历太空飞行后线虫生存率没有明显变化,但运动频率变慢,爬行轨迹也发生了改变,提示线虫运动功能出现障碍,这些数据揭示:微重力下秀丽线虫肌肉发育发生了变化.肌球蛋白A(myosin A)免疫荧光染色观察发现,太空飞行组肌纤维面积缩小,肌细胞致密体(dense-body)荧光亮度下降.这些形态学观察直接提示太空组线虫出现了肌萎缩.但是,肌动蛋白(F-actin)荧光染色显示两组并无明显差别.基因表达水平的分析结果显示,在太空飞行组动物中dys-1表达明显上调,同时hlh-1,myo-3,unc-54和egl—19基因表达下调.抗肌萎缩蛋白(dystrophin,由dys—1编码)是抗肌萎缩蛋白-糖蛋白复合物(DGC)的主要组成成分,而该复合物在微重力下增多,提示肌细胞是为了接受更多的力学刺激以维持细胞内外的力学平衡,所以该复合物在肌细胞的重力感知中起关键作用.基因hlh-1,myo-3,unc-54和egl-19表达下调,说明它们分别从结构和功能两个途径促进了微重力性肌萎缩的发生.最后,Western blot结果提示,太空组线虫体壁肌内肌球蛋白A减少,进一步确证了太空飞行中线虫有肌萎缩发生. 相似文献
15.
Dawe AS Nylund R Leszczynski D Kuster N Reader T De Pomerai DI 《Bioelectromagnetics》2008,29(2):92-99
Recent data suggest that there might be a subtle thermal explanation for the apparent induction by radiofrequency (RF) radiation of transgene expression from a small heat-shock protein (hsp16-1) promoter in the nematode, Caenorhabditis elegans. The RF fields used in the C. elegans study were much weaker (SAR 5-40 mW kg(-1)) than those routinely tested in many other published studies (SAR approximately 2 W kg(-1)). To resolve this disparity, we have exposed the same transgenic hsp16-1::lacZ strain of C. elegans (PC72) to higher intensity RF fields (1.8 GHz; SAR approximately 1.8 W kg(-1)). For both continuous wave (CW) and Talk-pulsed RF exposures (2.5 h at 25 degrees C), there was no indication that RF exposure could induce reporter expression above sham control levels. Thus, at much higher induced RF field strength (close to the maximum permitted exposure from a mobile telephone handset), this particular nematode heat-shock gene is not up-regulated. However, under conditions where background reporter expression was moderately elevated in the sham controls (perhaps as a result of some unknown co-stressor), we found some evidence that reporter expression may be reduced by approximately 15% following exposure to either Talk-pulsed or CW RF fields. 相似文献
16.
以种子萌发根尖和花药愈伤组织为材料,研究了取样时间、预处理方法对百日草染色体制片的影响。结果表明:根尖上午8:00~9:00,花药愈伤继代3~5d上午9:00~10:00为最佳取样预处理时间;采用三种药剂预处理活体根尖,以4℃下饱和对二氯苯溶液或0.002mol/L的8-羟基喹啉液预处理8h效果最佳,花药愈伤则以饱和对二氯苯溶液预处理6h效果最佳。本实验的预处理温度是固定的,可克服预处理随季节和时间温度的变化而带来的不稳定性,且百日草花药愈伤染色体观察为首次报道。 相似文献
17.
对野生秀丽四照花(Cornus hongkongensis subsp. elegans)种子的生物学特性进行观察测定,比较变温、低温层积、化学处理对种子萌发的影响。结果表明,秀丽四照花种子千粒重76.91 g,长5.81 mm、宽5.10 mm、厚3.99 mm。种子在整个试验过程中吸水率低于8%,说明有吸水性障碍的坚硬种皮抑制了种子萌发。变温条件下,温差较大的30℃/15℃处理对秀丽四照花种子萌发有较好的促进作用,萌发时滞短,萌发率和发芽势较高。秀丽四照花种子经30%NaOH浸泡10 min,可明显缩短萌发时间,但4℃低温层积处理对种子萌发没有显著效果。 相似文献
18.
Akira Sawada Tetsuya Iwasaki Chitose Inoue Kana Nakaoka Takumi Nakanishi Junpei Sawada Narumi Aso Syuya Nagai Haruka Ono Masaoki Takagi 《Population Ecology》2021,63(3):204-218
Top predators are frequently the target of conservation programs. Owls are such predators. However, previous studies of owls are biased to species occurring in temperate regions, whereas most owl species occur in tropical or subtropical regions and are understudied. Furthermore, owls are often endemic to islands and of unknown conservation status. Demographic data for such species are especially scarce although they are essential for initiating and promoting their conservation. As a case study of demographic analysis of owls in a tropical or subtropical area and on islands, we applied an integrated population model to 7-year monitoring data (2012–2018) of the Ryukyu Scops Owl population on Minami-daito Island, Japan. We used survival history data from 903 individuals, reproduction and sex ratio data from 213 broods, and count data of 2,526 individuals in total. Long-term averages of annual survival rates were 0.73 for adult females and 0.74 for adult males, although the sexual difference was not significant. Sex ratio estimates fluctuated annually and long-term averages were slightly skewed to males: 0.51 among fledglings, 0.54 among yearlings, and 0.52 among adults. Long-term averages of population size were estimated to be 273.4 females and 296.8 males. The long-term average of population growth rate was 0.98, suggesting a slightly declining trend. It was fortunate to recognize the declining trend during the early phase. Considering the general lack of fundamental ecological data on owls of tropical or subtropical areas and on islands, it seems likely that many endangered owl populations await conservation efforts. 相似文献
19.
The evolutionarily conserved Roundabout (Robo) family of axon guidance receptors control midline crossing of axons in response to the midline repellant ligand Slit in bilaterian animals including insects, nematodes, and vertebrates. Despite this strong evolutionary conservation, it is unclear whether the signaling mechanism(s) downstream of Robo receptors are similarly conserved. To directly compare midline repulsive signaling in Robo family members from different species, here we use a transgenic approach to express the Robo family receptor SAX-3 from the nematode Caenorhabditis elegans in neurons of the fruit fly, Drosophila melanogaster. We examine SAX-3’s ability to repel Drosophila axons from the Slit-expressing midline in gain of function assays, and test SAX-3’s ability to substitute for Drosophila Robo1 during fly embryonic development in genetic rescue experiments. We show that C. elegans SAX-3 is properly translated and localized to neuronal axons when expressed in the Drosophila embryonic CNS, and that SAX-3 can signal midline repulsion in Drosophila embryonic neurons, although not as efficiently as Drosophila Robo1. Using a series of Robo1/SAX-3 chimeras, we show that the SAX-3 cytoplasmic domain can signal midline repulsion to the same extent as Robo1 when combined with the Robo1 ectodomain. We show that SAX-3 is not subject to endosomal sorting by the negative regulator Commissureless (Comm) in Drosophila neurons in vivo, and that peri-membrane and ectodomain sequences are both required for Comm sorting of Drosophila Robo1. 相似文献
20.
Jrme Goudeau Catherine S Sharp Jonathan Paw Laura Savy Manuel D Leonetti Andrew G York Dustin L Updike Cynthia Kenyon Maria Ingaramo 《Genetics》2021,217(4)
We create and share a new red fluorophore, along with a set of strains, reagents and protocols, to make it faster and easier to label endogenous Caenorhabditis elegans proteins with fluorescent tags. CRISPR-mediated fluorescent labeling of C. elegans proteins is an invaluable tool, but it is much more difficult to insert fluorophore-size DNA segments than it is to make small gene edits. In principle, high-affinity asymmetrically split fluorescent proteins solve this problem in C. elegans: the small fragment can quickly and easily be fused to almost any protein of interest, and can be detected wherever the large fragment is expressed and complemented. However, there is currently only one available strain stably expressing the large fragment of a split fluorescent protein, restricting this solution to a single tissue (the germline) in the highly autofluorescent green channel. No available C. elegans lines express unbound large fragments of split red fluorescent proteins, and even state-of-the-art split red fluorescent proteins are dim compared to the canonical split-sfGFP protein. In this study, we engineer a bright, high-affinity new split red fluorophore, split-wrmScarlet. We generate transgenic C. elegans lines to allow easy single-color labeling in muscle or germline cells and dual-color labeling in somatic cells. We also describe a novel expression strategy for the germline, where traditional expression strategies struggle. We validate these strains by targeting split-wrmScarlet to several genes whose products label distinct organelles, and we provide a protocol for easy, cloning-free CRISPR/Cas9 editing. As the collection of split-FP strains for labeling in different tissues or organelles expands, we will post updates at doi.org/10.5281/zenodo.3993663 相似文献