Compensatory growth responses of seedlings of Pharbitis purpurea (Convulvulaceae) to tissue removal at different seeding depths of seeds

Tissue damage to seedlings can limit their later growth, and the further effects may be greater with increasing seedling age. Seedlings, however, can minimize the effect of damage through compensatory growth. Seedlings of Pharbitis purpurea grow in frequently disturbed habitats and generally tolerate damage to leaf tissues. We evaluated the compensatory responses of the cotyledon to different levels of defoliation and their effect on seedling growth and development. We also examined the relationship between seeding depth and compensatory growth. We tested seven defoliation treatments with one or both cotyledons and/or the apical meristem of seedlings removed from seeds buried at a seeding depth of either 2 or 5?cm. We then measured 12 growth traits of the seedlings to assess development and growth compensation. The area, thickness, biomass, and longevity of the remaining cotyledon were also measured to quantify increased growth as result of treatment effects at both seeding depths. The results showed that defoliation reduced seedling height, belowground length, and total biomass significantly in subsequent growth in all treatments. However, defoliation treatments had direct positive impacts on growth at 2?cm depth compared with 5?cm depth. In contrast, the compensation of cotyledon area (C _area), biomass (C _mass), and thickness (C _thickness) was greater at 5?cm depth than at 2?cm depth. The results thus indicate that P. purpurea seedlings adopted a compensatory growth strategy to resist leaf loss and minimize any adverse effects using the remaining cotyledon. Increasing seeding depth can aggravate the compensatory growth of remain cotyledon after partial defoliation.     

ATG12对缺氧缺血性脑病小鼠神经细胞凋亡和自噬的影响

目的探讨自噬相关蛋白12 （ATG12）对缺氧缺血性脑病（HIE）小鼠细胞凋亡和自噬的影响及分子机制。 方法通过尾静脉注射腺相关病毒构建ATG12低表达小鼠模型,将40只小鼠分为假手术组、HIE模型组、对照病毒模型（NC-HIE）组和ATG低表达病毒模型（ATG12 shRNA-HIE）组,HIE模型组小鼠左侧颈动脉结扎后低氧（8﹪氧气+92﹪氮气）处理2.5?h,假手术组不予结扎和低氧处理。缺氧处理后,荧光定量PCR检测脑组织ATG12 mRNA表达水平。比色法检测各组小鼠大脑神经细胞SOD和MDA水平;通过Tunel法检测各组小鼠大脑神经细胞凋亡水平;通过Western Blot检测各组小鼠大脑神经细胞LC3A/B、ATG12和SQSTM1/?p62蛋白表达水平。采用t检验和单因素方差分析对实验数据进行统计分析。 结果与假手术组小鼠脑组织ATG12 mRNA水平（1.00±0.14）相比,HIE模型组小鼠脑组织ATG12 mRNA水平（5.23±0.37）显著升高（t?= 33.60,P?< 0.01）;与假手术组小鼠脑组织超氧化物歧化酶（SOD）活性[（103.60±4.84）?U/?mgprot]和丙二醛（MDA）含量[（42.40±3.17）?μmol/?mgprot]比较,HIE模型组小鼠脑组织SOD活性[（62.60±3.44）?U/?mgprot]显著降低,MDA含量[（83.80±4.39）?μmol/?mgprot]显著升高,与NC-HIE组小鼠脑组织SOD活性[（61.20±4.39）?U/mgprot]和MDA含量[（85.20± 2.70）?μmol/?mgprot]比较,ATG12 shRNA-?HIE组小鼠脑组织SOD活性[（93.80± 5.43）?U/?mgprot]显著升高,MDA含量[（49.20±3.49）?μmol/mgprot]显著降低,差异具有统计学意义（F?= 222.7,P?< 0.01;F?=?415.8,P?相似文献   

微紫青霉CBHI酶的CBD蛋白编码区在大肠杆菌中的亚克隆及表达

对插入质粒pUC18－181上的微紫青霉（Penicilliumjanthinellum）CBHI酶的cDNA基因进行一系列DNA体外操作,包括进行序列定向缺失,最后将两末端修饰为平端后进行连接使质粒环化。用得到的产生序列定向缺失的重组质粒转化大肠杆菌JM109。利用CBD能吸附到结晶纤维素上的特性,从随机选取的24个缺失转化子中筛选到一株含CBD编码区的转化子JM109（pUC18C）,所表达的CBD融合蛋白分子量为21kD．JM109（pUC18C）所产生的LacZ-CBD融合蛋白可通过对纤维素的吸附-解吸附过程一步纯化。其IPTG诱导的pNPC酶活力为零,表明该菌已不再具有CBHI酶活力。     

Cloning, characterization and widespread expression analysis of testicular piRNA-like chicken RNAs

Piwi-interacting RNAs (piRNAs) are small RNAs abundant in the germline that have been implicated in germline development and maintenance of genomic integrity across several animal species including human, mouse, rat, zebrafish and drosophila. Tens of thousands of piRNAs have been discovered, yet abundant piRNAs have still not been detected in various eukaryotic organisms. This is a report on the characterization, cloning and expression profiling of piRNA-like chicken RNAs. Here, we identified 19 piRNAs, each 23–39 nucleotides long, from chicken testis using a small RNA cDNA library and T-A cloning methods. Three different pilRNAs were selected according to size, homology and secondary structure for temporal and spatial expression by Q-PCR technology in different tissues at five growth and four development stages of Chinese indigenous Rugao chickens (RG) and introduced recessive white feather chickens (RW). We found that, consistent to other organisms, pilRNA-encoding sequences within the chicken genome were asymmetrically distributed on the chromosomes while displaying a preference for intergenic regions across the genome. Interestingly, unlike miRNAs with unique stem-loop structures (mature miRNAs form stem section and the rest form loop section), distinct secondary structures of pilRNAs were predicted. In addition, chicken pilRNAs were not only abundant in the germline but also existed in somatic tissues, where, expression levels were influenced mainly by different pilRNAs, breed and gender. Taken together, our results suggest that two distinct secondary structures exist between pilRNAs and miRNAs, which may clarify the splicing and processing mechanisms of the two small RNAs are possible different. Moreover, our results suggest that pilRNAs may not only be confined to development and maintenance of the germline but may also play important roles in somatic tissues. Additionally, different pilRNAs may be involved in the unique regulatory machinery of complex biological processes.     

3个鸡种GARS-AIRS-GART基因第21号外显子的SNPs检测

采用PCR-SSCP和DNA测序法对安卡鸡、文昌鸡和如皋鸡中GARS-AIRS-GART基因的第21号外显子进行SNPs检测.结果发现该外显子含4个核苷酸多态位点:G29943A、C29968T、T30011C和C30017T,其中3处为非同义突变,分别为:29 943处天冬氨酸(Asp)→天冬酰胺(Asn)、30 011处色氨酸(Trp)→精氨酸(Arg)、30 017处精氨酸(Arg)→半胱氨酸(Cys);另一处为同义突变.对多态位点进行单倍型分析,发现12种单倍型,其中两种单倍型(5号和6号)的频率超过10%,分别为0.330 0和0.162 8,1号、3号、9号和10号单倍型频率介于1%～10%之间,其余都小于1%.另外共检测到11种基因型,存在5种等位基因,安卡鸡的D和E等位基因的基因频率较高,基因型与其它两个鸡品种之间都存在着极显著的差异(P<0.01),表明我国地方鸡种和外来鸡种在遗传组成上存在着差异.本研究将为鸡肉品质相关研究积累基础数据,为今后深入开展肉品质的开发利用奠定理论基础.     

Proprioceptive neuromuscular facilitation increases alpha absolute power in the dorsolateral prefrontal cortex and superior parietal cortex

The physiotherapist’s clinical practice includes proprioceptive neuromuscular facilitation (PNF), which is a treatment concept that accelerates the response of neuromuscular mechanisms through spiral and diagonal movements. The adaptations that occur in the nervous system following PNF are still poorly described in the literature. Thus, this study had a goal to investigate the electrophysiological changes in the fronto-parietal circuit during PNF and movement in sagittal and diagonal patterns. This study included 30 female participants, who were divided into three groups (control, PNF, and flexion groups). Electroencephalogram measurements were determined before and after tasks were performed by each group. For the statistical analysis, a two-way ANOVA was performed for the factors group and time. Interactions between the two factors were investigated using a one-way ANOVA. A value of p?相似文献   

Conformational dynamics of Tetracenomycin aromatase/cyclase regulate polyketide binding and enzyme aggregation propensity

BackgroundThe N-terminal domain of Tetracenomycin aromatase/cyclase (TcmN), an enzyme derived from Streptomyces glaucescens, is involved in polyketide cyclization, aromatization, and folding. Polyketides are a diverse class of secondary metabolites produced by certain groups of bacteria, fungi, and plants with various pharmaceutical applications. Examples include antibiotics, such as tetracycline, and anticancer drugs, such as doxorubicin. Because TcmN is a promising enzyme for in vitro production of polyketides, it is important to identify conditions that enhance its thermal resistance and optimize its function.MethodsTcmN unfolding, stability, and dynamics were evaluated by fluorescence spectroscopy, circular dichroism, nuclear magnetic resonance ¹⁵N relaxation experiments, and microsecond molecular dynamics (MD) simulations.ResultsTcmN thermal resistance was enhanced at low protein and high salt concentrations, was pH-dependent, and denaturation was irreversible. Conformational dynamics on the μs-ms timescale were detected for residues in the substrate-binding cavity, and two predominant conformers representing opened and closed cavity states were observed in the MD simulations.ConclusionBased on the results, a mechanism was proposed in which the thermodynamics and kinetics of the TcmN conformational equilibrium modulate enzyme function by favoring ligand binding and avoiding aggregation.General significanceUnderstanding the principles underlying TcmN stability and dynamics may help in designing mutants with optimal properties for biotechnological applications.     

Genomic Scan Reveals Loci under Altitude Adaptation in Tibetan and Dahe Pigs

High altitude environments are of particular interest in the studies of local adaptation as well as their implications in physiology and clinical medicine in human. Some Chinese pig breeds, such as Tibetan pig (TBP) that is well adapted to the high altitude and Dahe pig (DHP) that dwells at the moderate altitude, provide ideal materials to study local adaptation to altitudes. Yet, it is still short of in-depth analysis and understanding of the genetic adaptation to high altitude in the two pig populations. In this study we conducted a genomic scan for selective sweeps using F_ST to identify genes showing evidence of local adaptations in TBP and DHP, with Wuzhishan pig (WZSP) as the low-altitude reference. Totally, we identified 12 specific selective genes (CCBE1, F2RL1, AGGF1, ZFPM2, IL2, FGF5, PLA2G4A, ADAMTS9, NRBF2, JMJD1C, VEGFC and ADAM19) for TBP and six (OGG1, FOXM, FLT3, RTEL1, CRELD1 and RHOG) for DHP. In addition, six selective genes (VPS13A, GNA14, GDAP1, PARP8, FGF10 and ADAMTS16) were shared by the two pig breeds. Among these selective genes, three (VEGFC, FGF10 and ADAMTS9) were previously reported to be linked to the local adaptation to high altitudes in pigs, while many others were newly identified by this study. Further bioinformatics analysis demonstrated that majority of these selective signatures have some biological functions relevant to the altitude adaptation, for examples, response to hypoxia, development of blood vessels, DNA repair and several hematological involvements. These results suggest that the local adaptation to high altitude environments is sophisticated, involving numerous genes and multiple biological processes, and the shared selective signatures by the two pig breeds may provide an effective avenue to identify the common adaptive mechanisms to different altitudes.