北京市华北落叶松优树群体遗传多样性分析

利用SSR分子标记对北京市华北落叶松人工林5个群体的220棵优树进行遗传多样性和群体结构分析。20对SSR引物共检测到81个等位基因,每个位点等位基因数2~8个不等,平均4.05个。群体观测和期望杂合度平均值分别为0.429和0.440,Shannon信息指数和多态性信息含量分别为0.756和0.380。5个群体中,百花山和云蒙山遗传多样性水平最高,雾灵山遗传多样性水平最低。AMOVA分析结果显示,2.65%的遗传变异来自于群体间,剩余97.35%的遗传变异来自于群体内。遗传分化系数仅为0.023,表明北京市华北落叶松优树群体遗传分化程度很低。基于Nei's遗传距离可以将5个群体划分为3个类群,四海镇和雾灵山归为第Ⅰ类,松山归为第Ⅱ类,百花山和云蒙山归为第Ⅲ类。STRUCTURE群体结构分析结果与上述聚类分析结果大体一致。以上研究为华北落叶松人工林遗传多样性评价和优良种质资源收集、保护和利用提供理论依据。     

High‐throughput sequencing and graph‐based cluster analysis facilitate microsatellite development from a highly complex genome

Despite recent advances in high‐throughput sequencing, difficulties are often encountered when developing microsatellites for species with large and complex genomes. This probably reflects the close association in many species of microsatellites with cryptic repetitive elements. We therefore developed a novel approach for isolating polymorphic microsatellites from the club‐legged grasshopper (Gomphocerus sibiricus), an emerging quantitative genetic and behavioral model system. Whole genome shotgun Illumina MiSeq sequencing was used to generate over three million 300 bp paired‐end reads, of which 67.75% were grouped into 40,548 clusters within RepeatExplorer. Annotations of the top 468 clusters, which represent 60.5% of the reads, revealed homology to satellite DNA and a variety of transposable elements. Evaluating 96 primer pairs in eight wild‐caught individuals, we found that primers mined from singleton reads were six times more likely to amplify a single polymorphic microsatellite locus than primers mined from clusters. Our study provides experimental evidence in support of the notion that microsatellites associated with repetitive elements are less likely to successfully amplify. It also reveals how advances in high‐throughput sequencing and graph‐based repetitive DNA analysis can be leveraged to isolate polymorphic microsatellites from complex genomes.     

Actin exposure upon tissue injury is a targetable wound site-specific protein marker

BackgroundIdentification of wound-specific markers would represent an important step toward damaged tissue detection and targeted delivery of biologically important materials to injured sites. Such delivery could minimize the amount of therapeutic materials that must be administered and limit potential collateral damage on nearby normal tissues. Yet, biological markers that are specific for injured tissue sites remain elusive.MethodsIn this study, we have developed an immunohistological approach for identification of protein epitopes specifically exposed in wounded tissue sites.ResultsUsing ex-vivo tissue samples in combination with fluorescently-labeled antibodies we show that actin, an intracellular cytoskeletal protein, is specifically exposed upon injury. The targetability of actin in injured sites has been demonstrated in vivo through the specific delivery of anti-actin conjugated particles to the wounded tissue in a lethal rat model of grade IV liver injury.ConclusionsThese results illustrate that identification of injury-specific protein markers and their targetability for specific delivery is feasible.General significanceIdentification of wound-specific targets has important medical applications as it could enable specific delivery of various products, such as expression vectors, therapeutic drugs, hemostatic materials, tissue healing, or scar prevention agents, to internal sites of penetrating or surgical wounds regardless of origin, geometry or location.     

Focal adhesion kinase: predictor of tumour response and risk factor for recurrence after neoadjuvant chemoradiation in rectal cancer

Rectal cancer represents about 30% of colorectal cancers, being around 50% locally advanced at presentation. Chemoradiation (CRT) followed by total mesorectal excision is the standard of care for these locally advanced stages. However, it is not free of adverse effects and toxicity and the complete pathologic response rate is between 10% and 30%. This makes it extremely important to define factors that can predict response to this therapy. Focal adhesion kinase (FAK) expression has been correlated with worse prognosis in several tumours and its possible involvement in cancer radio‐ and chemosensitivity has been suggested; however, its role in rectal cancer has not been analysed yet. To analyse the association of FAK expression with tumour response to CRT in locally advanced rectal cancer. This study includes 73 patients with locally advanced rectal cancer receiving standard neoadjuvant CRT followed by total mesorectal excision. Focal adhesion kinase protein levels were immunohistochemically analysed in the pre‐treatment biopsies of these patients and correlated with tumour response to CRT and patients survival. Low FAK expression was significantly correlated with local and distant recurrence (P = 0.013). Low FAK expression was found to be a predictive marker of tumour response to neoadjuvant therapy (P = 0.007) and patients whose tumours did not express FAK showed a strong association with lower disease‐free survival (P = 0.01). Focal adhesion kinase expression predicts neoadjuvant CRT response in rectal cancer patients and it is a clinically relevant risk factor for local and distant recurrence.     

水稻粒簇生材料Cgr320的鉴定及遗传偏分离分析

籽粒簇生稻Cgr320为一类水稻突变材料,其性状表现为2~3朵颖花(籽粒)簇生在水稻主穗轴或枝梗顶部。为了进一步明确其簇生性状的遗传机制,本研究用Cgr320作父本分别与武运粳24和93-11配制了2个杂交组合,获得杂种F1、F2分离群体,对亲本、F1和F2群体的簇生性状进行了形态学观察和遗传连锁分析。结果表明,Cgr320其他农艺性状与普通栽培稻差异不显著。簇生性状在F1植株表现为野生型,在F2群体中出现严重偏离孟德尔(3∶1)遗传分离,卡方测验值X2(3∶1)为7.71和144.87。随机选取第1、2、3、4、5、6、7、8、9、10、11和12染色体上RM493、RM3762、RM1338、RM3217、RM249、RM20155、RM3325、RM22418、RM6797、RM1146、RM7557和RM27706等12对微卫星标记对武运粳24/Cgr320 22个F2隐性(簇生)单株进行遗传连锁分析,发现12个标记所扩增的22个F2隐性单株基因型都极显著偏向武运粳24,卡方检验值X2(1∶2∶1)大于X2(0.05,2)临界值5.991,控制cgr320簇生性状基因存在严重偏分离遗传,这种遗传现象必将误导我们判定控制籽粒簇生基因所在的连锁群。本研究结果将为水稻基因定位研究提供参考信息。     

Estimation of hurdle clearance parameters using a monocular human motion tracking method

This paper presents a method of monocular human motion tracking for estimation of hurdle clearance kinematic parameters. The analysis involved 10 image sequences of five hurdlers at various training levels. Recording of the sequences was carried out under simulated starting conditions of a 110 m hurdle race. The parameters were estimated using the particle swarm optimization algorithm and they are based on analysis of the images recorded with a 100 Hz camera. The proposed method does not involve using any special clothes, markers, inertial sensors, etc. As the quality criteria, the mean absolute error and mean relative error were used. The level of computed errors justifies the use of this method to estimate hurdle clearance parameters.     

Stability of cytokines,chemokines and soluble activation markers in unprocessed blood stored under different conditions

BackgroundBiomarkers such as cytokines, chemokines, and soluble activation markers can be unstable when processing of blood is delayed. The stability of various biomarkers in serum and plasma was investigated when unprocessed blood samples were stored for up to 24 h at room and refrigerator temperature.MethodsBlood was collected from 16 healthy volunteers. Unprocessed serum, EDTA and heparinized blood was stored at room (20–25 °C) and refrigerator temperature (4–8 °C) for 0.5, 2, 4, 6, 8, and 24 h after collection before centrifugation and separation of serum and plasma. Samples were batch tested for various biomarkers using commercially available immunoassays. Statistically significant changes were determined using the generalized estimating equation.ResultsIFN-γ, sIL-2Rα, sTNF-RII and β₂-microglobulin were stable in unprocessed serum, EDTA and heparinized blood samples stored at either room or refrigerator temperature for up to 24 h. IL-6, TNF-α, MIP-1β and RANTES were unstable in heparinized blood at room temperature; TNF-α, and MIP-1β were unstable in unprocessed serum at room temperature; IL-12 was unstable in unprocessed serum at refrigerator temperature; and neopterin was unstable in unprocessed EDTA blood at room temperature. IL-1ra was stable only in unprocessed serum at room temperature.ConclusionAll the biomarkers studied, with the exception of IL-1ra, were stable in unprocessed EDTA blood stored at refrigerator temperature for 24 h. This indicates that blood for these biomarkers should be collected in EDTA and if delays in processing are anticipated the unseparated blood should be stored at refrigerator temperature until processing.     

EDTA/gelatin zymography method to identify C1s versus activated MMP‐9 in plasma and immune complexes of patients with systemic lupus erythematosus

Gelatin zymography analysis is a sensitive method and commonly used to characterize and quantify the presence of the gelatinases (MMP‐2 and MMP‐9) in biological samples. In human plasma samples from healthy controls and systemic lupus erythematosus (SLE) patients, we observed a gelatinolytic molecule at 80 kDa, suggestive for activated human MMP‐9. However, by developing and using the EDTA/gelatin zymography method and after purification of the 80 kDa entity, we proved that this molecule was the C1s subunit of the complement system. The zymolytic capacity of C1s was validated and found to be enhanced, in the absence of calcium and in the presence of EDTA. Our findings indicate that for correct identification of gelatinolytic proteins in complex biological samples the use of EDTA/gelatin zymography for enzyme development is advised. In addition, by quantification of EDTA/gelatin zymography analysis and ELISA, we observed that the levels of C1s were higher in plasma and immune complexes of SLE patients than of healthy individuals. Therefore, our data imply that C1s may become a marker for the diagnosis of SLE.     

Phenotypic Characteristics and Fatty Acid Composition of Seeds from Different Herbaceous Peony Species Native to China

Herbaceous peony has been widely cultivated in China due to its substantial ornamental and medicinal value. In the present study, the phenotypic characteristics, total fatty acid (FA) content, and nine FA compositions of herbaceous peony seeds from 14 populations belonging to six species and one subspecies were determined by normal test and gas chromatography/mass spectrometry (GC/MS). The results showed that the phenotypic characteristics of seeds varied dramatically among species. The concentrations of five major FAs in seed oils were as follows: linoleic acid (173.95–236.51 μg/mg), linolenic acid (227.82–302.71 μg/mg), oleic acid (135.32–208.81 μg/mg), stearic acid (6.52–11.7 μg/mg), and palmitic acid (30.67–47.64 μg/mg). Correlation analysis demonstrated that oleic acid had the highest partial correlation coefficient with total FAs and might be applied to develop a model of phenotypic characteristics. FAs were significantly influenced by the following environmental factors: latitude, elevation, and annual average temperature. Based on the FA levels in the seed oils, clustering analysis divided 14 populations into two clusters. It was found that the average contents of oleic acid, linoleic acid, and total FAs in cluster I (147.16 μg/mg, 200.31 μg/mg, and 671.24 μg/mg, respectively) were significantly lower than those in cluster II (196.65 μg/mg, 220.16 μg/mg, and 741.78 μg/mg, respectively). Cluster I was perfectly consistent with subsect. Foliolatae, while cluster II was in good agreement with subsect. Dissectifoliae. Therefore, the FA composition of wild herbaceous peony seed oil might be used as a chemotaxonomic marker.