The complete mitochondrial genome of Pseudochauhanea macrorchis (Monogenea: Chauhaneidae) revealed a highly repetitive region and a gene rearrangement hot spot in Polyopisthocotylea

The complete mitochondrial genome of Pseudochauhanea macrorchis was determined and compared with other monogenean mitochondrial genomes from GenBank. The circular genome was 15,031 bp in length and encoded 36 genes (12 protein-coding genes, two ribosomal RNAs, and 22 transfer RNAs) typically found in flatworms. Structures of the mitochondrial genome were mostly concordant with that known for Microcotyle sebastis and Polylabris halichoeres, but also contained two noted features-a gene rearrangement hot spot and the highly repetitive region (HRR) in major non-coding region (NCR). The gene rearrangement hot spot located between the cox3 and nad5 genes, including a cluster of tRNA genes, nad6 gene and one major NCR. The HRR seemed to be a unique feature of the polyopisthocotylean mitochondrial genomes. In conclusion, the present study provided new molecular data for future studies of the comparative mitochondrial genomics and also served as a resource of markers for the studies of species populations and monogenean phylogenetics.     

Crb apical polarity proteins maintain zebrafish retinal cone mosaics via intercellular binding of their extracellular domains

Cone photoreceptors are assembled by unknown mechanisms into geometrically regular mosaics in many vertebrate species. The formation and maintenance of photoreceptor mosaics are speculated to require differential cell-cell adhesion. However, the molecular basis for this theory has yet to be identified. The retina and many other tissues express Crumbs (Crb) polarity proteins. The functions of the?extracellular domains of Crb proteins remain to be understood. Here we report cell-type-specific expression of the crb2a and crb2b genes at the cell membranes of photoreceptor inner segments and Müller cell apical processes in the zebrafish retina. We demonstrate that the extracellular domains of Crb2a and Crb2b mediate a cell-cell adhesion function, which plays an essential role in maintaining the integrity of photoreceptor layer and cone mosaics. Because Crb proteins are expressed in many types of epithelia, the Crb-based cell-cell adhesion may underlie cellular patterning in other epithelium-derived tissues as well.     

Mono- and trivalent ions around DNA: a small-angle scattering study of competition and interactions

The presence of small numbers of multivalent ions in DNA-containing solutions results in strong attractive forces between DNA strands. Despite the biological importance of this interaction, e.g., DNA condensation, its physical origin remains elusive. We carried out a series of experiments to probe interactions between short DNA strands as small numbers of trivalent ions are included in a solution containing DNA and monovalent ions. Using resonant (anomalous) and nonresonant small angle x-ray scattering, we coordinated measurements of the number and distribution of each ion species around the DNA with the onset of attractive forces between DNA strands. DNA-DNA interactions occur as the number of trivalent ions increases. Surprisingly good agreement is found between data and size-corrected numerical Poisson-Boltzmann predictions of ion competition for non- and weakly interacting DNAs. We also obtained an estimate for the minimum number of trivalent ions needed to initiate DNA-DNA attraction.     

Decreased surfactant protein B expression in mice derived completely from embryonic stem cells

ES mice that are derived completely from embryonic stem (ES) cells can be obtained by tetraploid embryo complementation. Many neonate ES mice die because of respiratory distress, but it is not clear what contributes to the phenomenon. Using five microsatellite DNA markers, we confirmed that our ES mice were completely derived from ES cells and contained no tetraploid component. The neonatal ES mice that exhibited respiratory distress were tested for surfactant protein B (SP-B) expression by Western blotting. These mice had no SP-B expression, and even apparently healthy adult ES mice had decreased SP-B levels and aberrant SP-B phenotypes. These data suggest that the expression of SP-B protein is an important factor in the survival of ES mice to term and adulthood.     

Optimisation of enzyme-assisted extraction of Erythronium sibiricum bulb polysaccharide and its effects on immunomodulation

Glycoconjugate Journal - In this study, polysaccharides of Erythronium sibiricum bulb were extracted using enzyme-assisted extraction technology and then optimised by response surface methodology....     

依诺沙星栓对前列腺炎疗效的实验研究

为了证实依诺沙星对慢性前列腺炎的临床疗效,作建立了细菌性前列腺炎动物模型,并用依诺沙星栓腊门直肠给药和用依诺沙星粉喂饲给药分别进行治疗。对治疗前后动物的尿液、前列腺液化验检查,同时观察研究了前列腺组织的形态和酶组织化学反应。结果表明：依诺沙星栓疗效较好。     

SWATH enables precise label‐free quantification on proteome scale

MS‐based proteomics has emerged as a powerful tool in biological studies. The shotgun proteomics strategy, in which proteolytic peptides are analyzed in data‐dependent mode, enables a detection of the most comprehensive proteome (>10 000 proteins from whole‐cell lysate). The quantitative proteomics uses stable isotopes or label‐free method to measure relative protein abundance. The isotope labeling strategies are more precise and accurate compared to label‐free methods, but labeling procedures are complicated and expensive, and the sample number and types are also limited. Sequential window acquisition of all theoretical mass spectra (SWATH) is a recently developed technique, in which data‐independent acquisition is coupled with peptide spectral library match. In principle SWATH method is able to do label‐free quantification in an MRM‐like manner, which has higher quantification accuracy and precision. Previous data have demonstrated that SWATH can be used to quantify less complex systems, such as spiked‐in peptide mixture or protein complex. Our study first time assessed the quantification performance of SWATH method on proteome scale using a complex mouse‐cell lysate sample. In total 3600 proteins got identified and quantified without sample prefractionation. The SWATH method shows outstanding quantification precision, whereas the quantification accuracy becomes less perfect when protein abundances differ greatly. However, this inaccuracy does not prevent discovering biological correlates, because the measured signal intensities had linear relationship to the sample loading amounts; thus the SWATH method can predict precisely the significance of a protein. Our results prove that SWATH can provide precise label‐free quantification on proteome scale.     

樟子松人工固沙林衰退的规律和原因

系统地研究了章古台地区樟子松人工固沙林衰退的规律和起因．结果表明,天然分布区以外的樟子松人工固沙林衰退是一种生命周期缩短、成熟期提前的早衰现象．松枯梢病侵害是樟子松枯死的直接原因,樟子松衰退是由多种生物与非生物因素综合引起的,属于侵染性病害和非侵染性病害之外的第三类病害,即“森林衰退病”,气候差异过大、经营管理不当、土壤水分利用失衡、大气氮沉降超标准是诱导因素,其中气候差异、土壤水分利用失衡起主导作用,松沫蝉、松毛虫危害是促进因素,松枯梢病侵染是激化因素。     

不同温度下斜纹夜蛾感染核型多角体病毒的流行病模型及模拟

研究了温度对斜纹夜蛾核型多角体病毒病流行的影响.结果表明,温度在29 ℃以上时,感病幼虫大多在2～3 d开始死亡,4～5 d达到高峰.随着温度的升高,感病幼虫病死率增加,病死速度加快.在试验温度范围内,未发现该病毒的热抑制温度,但感病幼虫死亡速率存在恒定温区,在29～35 ℃之间.感病幼虫的每日病死率可用互补重对数模型较好地拟合,累计病死时间分布可用Gompertz模型拟合,生物物理模型经改进后可很好地描述幼虫病死速率与温度的关系,可用于模拟分析不同温度下的幼虫病死时间分布和幼虫病死速率.     

樟子松人工固沙林衰退的主要特征

针对辽宁省章古台地区樟子松人工固沙林出现的衰退枯死现象,系统地研究了樟子松人工固沙林衰退的主要特征,结果表明,衰退的樟子松人工固沙林外貌景观呈灰绿色,针叶纤细,开花结实率低,平均单株球果数量为10．4～16．5个,成熟种子千粒重为6．96～7.39g,种子空粒、涩粒较多．生长季内2年生针叶营养元素季节变化规律相似,但N、P含量下降,K含量明显增高,表明养分循环失调;衰退林分2年生针叶叶绿素含量较高,健康林分1年生较高且增幅较大．松枯梢病的侵害是樟子松人工固沙林衰退的最明显标志．林分衰退后,树高和胸径生长量下降明显,林分胸径分布结构“左移”(径级小的株数增多),衰弱(亡)木数量增加了15.9％～27．2％;根量分别减少了22．9％～28．9％。其中吸收根减少量最大。