Biotransformation of 4‐fluoro‐N‐(1‐{2‐[(propan‐2‐yl)phenoxy]ethyl}‐8‐azabicyclo[3.2.1]octan‐3‐yl)‐benzenesulfonamide,a novel potent 5‐HT7 receptor antagonist with antidepressant‐like and anxiolytic properties: In vitro and in silico approach

The aim of the study was to investigate the metabolism of 4‐fluoro‐N‐(1‐{2‐[(propan‐2‐yl)phenoxy]ethyl}‐8‐azabicyclo[3.2.1]octan‐3‐yl)‐benzenesulfonamide (PZ‐1150), a novel 5‐HT₇ receptor antagonist with antidepressant‐like and anxiolytic properties, by the following three ways: in vitro with microsomes; in vitro employing Cunninghamella echinulata, and in silico using MetaSite. Biotransformation of PZ‐1150 with microsomes resulted in five metabolites, while transformation with C. echinulata afforded two metabolites. In both models, the predominant metabolite occurred due to hydroxylation of benzene ring. In silico data coincide with in vitro experiments, as three MetaSite metabolites matched compounds identified in microsomal samples. In human liver microsomes PZ‐1150 exhibited in vitro half‐life of 64 min, with microsomal intrinsic clearance of 54.1 μL/min/mg and intrinsic clearance of 48.7 mL/min/kg. Therefore, PZ‐1150 is predicted to be a high‐clearance agent. The study demonstrated the applicability of using microsomal model coupled with microbial model to elucidate the metabolic pathways of compounds and comparison with in silico metabolite predictions.     

桃ERF转录因子家族生物信息学分析及 芽萌发相关基因筛选

以中油四号油桃(Prunus persica var. nectarina)为研究对象, 利用MEGA 6.0、MEME、GSDS和DNAMAN 6.0等软件对桃ERF家族数据进行生物信息学分析, 鉴定得到102个ERF转录因子家族基因, 并通过构建系统进化树将这102个基因分为10个子家族(I-X)。基因结构分析表明, 有81个基因不含内含子, 20个基因含有1个内含子, 有1个基因与其它成员差异较大, 含有5个内含子。保守元件分析表明, ERF家族包含20个保守元件, 其中Motif 1、Motif 2和Motif 4都属于AP2/ERF结构域, 同一个保守元件主要出现在同一个子家族中, 并且大部分保守元件的功能未知。VIII子家族基因的荧光定量PCR分析表明, 在桃叶芽处于不同的发育状态时, PpeERF068的表达量存在较大差异, 光照培养箱中培养的桃芽在萌发过程中各时期表达量变化趋势进一步表明该基因可能与叶芽萌发有关, 将其命名为PpeEBB1。该研究为进一步揭示PpeEBB1的分子机制奠定了基础, 并为桃树的栽培管理和熟期调控了提供理论指导。     

Testing hypotheses driving genetic structure in the cooperatively breeding Brown‐headed Nuthatch Sitta pusilla

Habitat fragmentation has often been implicated in the decline of many species. For habitat specialists and/or sedentary species, loss of habitat can result in population isolation and lead to negative genetic effects. However, factors other than fragmentation can often be important and also need to be considered when assessing the genetic structure of a species. We genotyped individuals from 13 populations of the cooperatively breeding Brown‐headed Nuthatch Sitta pusilla in Florida to test three alternative hypotheses regarding the effects that habitat fragmentation might have on genetic structure. A map of potential habitat developed from recent satellite imagery suggested that Brown‐headed Nuthatch populations in southern Florida occupied smaller and more isolated habitat patches (i.e. were more fragmented) than populations in northern Florida. We also genotyped individuals from a small, isolated Brown‐headed Nuthatch population on Grand Bahama Island. We found that populations associated with more fragmented habitat in southern Florida had lower allelic richness than populations in northern Florida (P = 0.02), although there were no differences in heterozygosity. Although pairwise estimates of F_ST were low overall, values among southern populations were generally higher than northern populations. Population assignment tests identified K = 3 clusters corresponding to a northern cluster, a southern cluster and a unique population in southeast Florida; using sampling localities as prior information revealed K = 7 clusters, with greater structure only among southern Florida populations. The Bahamas population showed moderate to high differentiation compared with Florida populations. Overall, our results suggest that fragmentation could affect gene flow in Brown‐headed Nuthatch populations and is likely to become more pronounced over time.     

下辽河平原降雨中氮素的动态变化

为了了解降雨中氮对农田生态系统的影响,分析了2004-2006年下辽河平原连续3年定位收集的降雨观测资料与历史资料.结果表明:降雨中氮输入量季节变化显著,夏季最高,这主要与降雨量及空气中NH4 -N浓度变化有关;降雨中DON量与NO3--N含量相当,均接近24%,是雨水中氮的重要组分;与1985年相比,近3年降雨输入到该地区农田生态系统的年氮通量已有较大提高,降雨较多的2005年输入的无机氮量更是20年前的2倍以上;2004-2006年随降雨输入农田生态系统的氮平均占可利用肥料氮的28.3%,对农田生态系统有着重要影响.     

荷叶铁线蕨自然居群的遗传多样性研究

荷叶铁线蕨(Adiantumreniformevar. sinense)为我国特有植物,具有重要的经济价值,目前仅分布于重庆的少数地区。近几十年来,由于过度开发,该种的分布范围日益缩小,已处于灭绝的边缘。本研究利用等位酶标记检测了荷叶铁线蕨 6个自然居群共 136个个体的遗传多样性,共检测到了 5个酶系统的 14个位点,获得了 7个多态位点。结果表明:与其他蕨类植物相比,荷叶铁线蕨居群内的遗传多样性水平比较低。平均每位点的有效等位基因数(Ae)为 1. 778,多态位点百分率(P)为 0. 441,期望杂合度(He)为 0. 199,观察杂合度 (Ho)为 0. 235。其居群间的遗传分化也很低,居群间的遗传变异仅占总变异的 1. 49%,而 98. 51%的变异存在于居群内部。采用Hardy Wein berg平衡和固定指数F对荷叶铁线蕨的居群遗传结构进行了分析,结果表明其种群可能是以配子体间异交为主的混合交配体系。导致荷叶铁线蕨濒危的主要原因是生境的破坏以及过度开采所导致的生境片断化使其居群变小、近交率加大、遗传变异趋低,降低了其生存以及进化的潜力。     

PEGylation of lysine residues improves the proteolytic stability of fibronectin while retaining biological activity

Excessive proteolysis of fibronectin (FN) impairs tissue repair in chronic wounds. Since FN is essential in wound healing, our goal is to improve its proteolytic stability and at the same time preserve its biological activity. We have previously shown that reduced FN conjugated with polyethylene glycol (PEG) at cysteine residues is more proteolytically stable than native FN. Cysteine‐PEGylated FN supported cell adhesion and migration to the same extent as native FN. However, unlike native FN, cysteine‐PEGylated FN was not assembled into an extracellular matrix (ECM) when immobilized. Here, we present an alternative approach in which FN is preferentially PEGylated at lysine residues using different molecular weight PEGs. We show that lysine PEGylation does not perturb FN secondary structure. PEG molecular weight, from 2 to 10 kDa, positively correlates with FN–PEG proteolytic stability. Cell adhesion, cell spreading, and gelatin binding decrease with increasing molecular weight of PEG. The 2‐kDa FN–PEG conjugate shows comparable cell adhesion to native FN and binds gelatin. Moreover, immobilized FN–PEG is assembled into ECM fibrils. In summary, lysine PEGylation of FN can be used to stabilize FN against proteolytic degradation with minimal perturbation to FN structure and retained biological activity.     

对TMV不同抗性番茄品种的叶绿体DNA限制性内切酶酶谱分析

选用对TMV有抗性和敏感的番茄品种、制备其ct-DNA, 用限制性内切酶BumHI、EcoRI和PstI完全酶解, 三种酶切图谱与前人报道一致, 由酶切片段计算番茄ct-DNA。分子量约为156.9kb。比较抗性和敏感品种的ct-DNA图谱, 发现三种酶切图谱均存在差异, 但由差异片段计算分子量之和又很除近。我们推测这是由于检基顺序变异或小段DNA顺序插入或缺失所造成, 由此证明, 叶绿体基因组与核中的TMV抗性基因, 共同决定着植物体对TMV的抗性。