Use of blood-based biomarkers for early diagnosis and surveillance of colorectal cancer

Early screening for colorectal cancer(CRC) holds the key to combat and control the increasing global burden of CRC morbidity and mortality. However, the current available screening modalities are severely inadequate because of their high cost and cumbersome preparatory procedures that ultimately lead to a low participation rate. People simply do not like to have colonoscopies. It would be ideal, therefore, to develop an alternative modality based on blood biomarkers as the first line screening test. This will allow for the differentiation of the general population from high risk individuals. Colonoscopy would then become the secondary test, to further screen the high risk segment of the population. This will encourage participation and therefore help to reach the goal of early detection and thereby reduce the anticipated increasing global CRC incidence rate. A blood-based screening test is anappealing alternative as it is non-invasive and poses minimal risk to patients. It is easy to perform, can be repeated at shorter intervals, and therefore would likely lead to a much higher participation rate. This review surveys various blood-based test strategies currently under investigation, discusses the potency of what is available, and assesses how new technology may contribute to future test design.

Confirmation of Pearl Millet-Napiergrass Hybrids Using EST-Derived Simple Sequence Repeat (SSR) Markers

Prospects for deploying perennial grasses that are currently considered leading candidates for dedicated energy crops over large acreages are debatable because of several limitations, including vegetative propagation or small seed size, low biomass production during the first growing season, and incomplete assessments of crop invasiveness risk. Pearl Millet-Napiergrass hybrids (“PMN”;Pennisetum glaucum [L.] R. Br. × P. purpureum Schumach.), in contrast, are large-seeded, sterile feedstocks capable of high biomass production during establishment year. Novel methods are warranted for confirmation of PMN hybrids, as traditional morphological observations can be inconclusive and chromosome number determination using cytological methods is laborious and time consuming. Six putative PMN lines were produced in this study, and 10 progeny from each line were evaluated using morphological traits, seed fertility, flow cytometry, and expressed sequence tag-simple sequence repeat (EST-SSR) markers. All putative hybrid lines were sterile and failed to produce seed. The PMN hybrids could not be distinguished from either parent using flow cytometry due to highly similar nuclear genome DNA contents. A number of paternal napiergrass-specific EST-SSRs were identified for each PMN line, and four paternal-specific EST-SSRs conserved across all napiergrass accessions were selected to screen the putative PMN hybrids. These EST-SSRs confirmed that all F1 individuals analyzed were PMN hybrids. The use of paternal-specific markers therefore provides a valuable tool in the development of both “Seeded-yet-Sterile” biofuel PMN feedstocks and additional PMN cultivar-and parental species-specific markers.

骨代谢生化指标临床应用专家共识(2023修订版)

骨代谢生化指标的临床应用,为骨质疏松的诊断、鉴别诊断、预测骨折风险及抗骨质疏松治疗疗效评价提供了分子生物学依据,并在骨质疏松流行病学研究、发病机制、骨质疏松药物开发研究方面具有重要意义。由于骨代谢生化指标检测特异性强、灵敏度高,其应用日趋广泛。该文检索了大量中外文献,编审了《骨代谢生化指标临床应用专家共识》(2023修订版),对骨代谢生化指标的分类、骨代谢生化指标的方法学以及生物学意义、骨代谢指标的检测变异等进行了论述。

Monocyte chemotactic protein-1 and soluble adhesion molecules as possible prognostic markers of the efficacy of antiviral treatment in chronic hepatitis C

AIM:To explain the role of Monocyte chemotactic protein-1 (MCP-1) and soluble adhesion molecules in chronic hepatitis C during the treatment of interferon alpha (IFNα) 2 b and ribavirin (RBV). METHODS:Concentrations of MCP-1,soluble adhesion molecules intercellular adhesion molecule-1 (sICAM-1),sP- selectin,interleukin (IL) 6,and IL10 in serum were estimated in the group of 40 patients with chronic hepatitis C treated with IFNalpha2 b and RBV in 0,16,32,48 wk of the therapy, RESULTS:In chronic hepatitis C,before and during the treatment,the serum levels of MCP-1 and sP-selectin in responders were similar to those of healthy subjects.In non- responders (NR),MCP-1 increased in the course of IFNc^+RBV treatment,differences were statistically significant as compared to responders.MCP-1 correlated statistically with the activity of periportal inflammation (r=0.35,P<0.05) but not with staging of liver fibrosis,sICAM-1 positively correlated with inflammatory activity and fibrosis in NR.sP-selectin did not correlate with histological findings in the liver.The MCP-1 correlated with the soluble form of sP-selectin concentrations (r= 6,P<0.001) and with IL-10 level in NR (r=0.4,P<0.05).There was no correlation observed between the concentration of MCP-1 and sICAM-1,IL-6 during the treatment. CONCLUSION:MCP-1 concentration may be a prognostic marker of the efficacy of IFN+RBV therapy in patients with chronic hepatitis C.

Inflammatory and nutritional markers in colorectal cancer: Implications for prognosis and treatment

The prognosis of colorectal cancer(CRC)patients with peritoneal metastasis remains poor despite advancements in detection and treatment.Preoperative inflammatory and nutritional markers have emerged as significant predictors of prognosis in CRC,potentially guiding treatment decisions and improving patient outcomes.This editorial explores the prognostic value of markers such as the neutrophil-to-lymphocyte ratio,hemoglobin,and serum albumin levels.By integrating these markers into prognostic models,clinicians can better stratify patients,personalize treatment strategies,and ultimately enhance clinical outcomes.This review highlights the importance of these markers in providing a comprehensive assessment of patient condition and underscores the need for further research to validate their clinical utility and uncover underlying mecha-nisms.

Storage time affects the level and diagnostic efficacy of plasma biomarkers for neurodegenerative diseases

Several promising plasma biomarker proteins,such as amyloid-β(Aβ),tau,neurofilament light chain,and glial fibrillary acidic protein,are widely used for the diagnosis of neurodegenerative diseases.However,little is known about the long-term stability of these biomarker proteins in plasma samples stored at-80°C.We aimed to explore how storage time would affect the diagnostic accuracy of these biomarkers using a large cohort.Plasma samples from 229 cognitively unimpaired individuals,encompassing healthy controls and those experiencing subjective cognitive decline,as well as 99 patients with cognitive impairment,comprising those with mild cognitive impairment and dementia,were acquired from the Sino Longitudinal Study on Cognitive Decline project.These samples were stored at-80°C for up to 6 years before being used in this study.Our results showed that plasma levels of Aβ42,Aβ40,neurofilament light chain,and glial fibrillary acidic protein were not significantly correlated with sample storage time.However,the level of total tau showed a negative correlation with sample storage time.Notably,in individuals without cognitive impairment,plasma levels of total protein and tau phosphorylated protein threonine 181(p-tau181)also showed a negative correlation with sample storage time.This was not observed in individuals with cognitive impairment.Consequently,we speculate that the diagnostic accuracy of plasma p-tau181 and the p-tau181 to total tau ratio may be influenced by sample storage time.Therefore,caution is advised when using these plasma biomarkers for the identification of neurodegenerative diseases,such as Alzheimer's disease.Furthermore,in cohort studies,it is important to consider the impact of storage time on the overall results.

Urgent need for prognostic markers for hepatocellular carcinoma in the light of genomic instability and non-coding RNA signatures

In this editorial,we comment on an original article by Duan et al.Despite ad-vancements in the diagnosis and treatment of hepatocellular carcinoma(HCC),the identification of suitable prognostic factors remains challenging.In their paper,Duan et al identified long non-coding RNAs(LncRNAs)to quantify ge-nomic instability(GI)by combining LncRNA expression and somatic mutation profiles.They confirmed that the GI-derived LncRNA signature(GI-LncSig)could be an independent prognostic factor with the area under the curve of 0.773.Fur-thermore,the authors stated that GI-LncSig may have a better predictive perfor-mance than TP53 mutation status alone.However,studies exploring genetic markers for predicting the prognosis of HCC are crucial for identifying thera-peutic targets and enhancing diagnostic and treatment strategies to mitigate the global burden of liver cancer.

Assessment of molecular markers and marker-assisted selection for drought tolerance in barley(Hordeum vulgare L.)

This review updates the present status of the field of molecular markers and marker-assisted selection(MAS),using the example of drought tolerance in barley.The accuracy of selected quantitative trait loci(QTLs),candidate genes and suggested markers was assessed in the barley genome cv.Morex.Six common strategies are described for molecular marker development,candidate gene identification and verification,and their possible applications in MAS to improve the grain yield and yield components in barley under drought stress.These strategies are based on the following five principles:(1)Molecular markers are designated as genomic‘tags’,and their‘prediction’is strongly dependent on their distance from a candidate gene on genetic or physical maps;(2)plants react differently under favourable and stressful conditions or depending on their stage of development;(3)each candidate gene must be verified by confirming its expression in the relevant conditions,e.g.,drought;(4)the molecular marker identified must be validated for MAS for tolerance to drought stress and improved grain yield;and(5)the small number of molecular markers realized for MAS in breeding,from among the many studies targeting candidate genes,can be explained by the complex nature of drought stress,and multiple stress-responsive genes in each barley genotype that are expressed differentially depending on many other factors.

Serum tumor markers (carcinoembryonic antigen, carbohydrate antigen 19-9, carbohydrate antigen 72-4, carbohydrate antigen 24-2, ferritin) and gastric cancer prognosis correlation

BACKGROUND Gastric cancer is a kind of malignant tumor which is prevalent all over the world.Although some progress has been made in the treatment of gastric cancer,its prognosis is still not optimistic,so it is of great significance to find reliable prog-nostic indicators to guide the treatment and management of patients with gastric cancer.AIM To explore the relationship between serum levels of five biomarkers[carcinoem-bryonic antigen(CEA),carbohydrate antigen(CA)19-9,CA72-4,CA24-2,and ferritin]and prognosis in patients with gastric cancer.METHODS This study included 200 patients with gastric adenocarcinoma,and conducted an in-depth analysis of their baseline characteristics,relationship between tumor markers and staging,and prognosis.The study found that CA19-9 has a signi-ficant correlation with tumor stage,the average levels of CA24-2,CEA,CA72-4 and ferritin were slightly increased disregarding the stage of tumor.Survival analysis showed that increases in CEA,CA19-9,CA24-2,and ferritin were all associated with shortened overall survival of patients.Further multivariate ana-lysis revealed that elevated serum CA72-4 levels were an inde-pendent adverse prognostic factor.RESULTS This study reveals that there is a significant correlation between the expression levels of serum tumor markers CEA,CA19-9,CA72-4,CA24-2 and ferritin in patients with gastric cancer and prognosis,and can be used as important indicators for prognostic evaluation of gastric cancer.In particular,markers that appear abnormally elevated initially may help identify gastric cancer patients with poor prognosis.CONCLUSION Serum CEA and CA19-9 play an important role in the prognosis assessment of gastric cancer,and are effective tools to guide clinical practice and optimize individualized treatment strategies for gastric cancer patients.

Effect of Kang Ai injection + conventional chemotherapy on tumor markers, apoptotic molecules and immune response in patients with advanced NSCLC

Objective: To study the effects of Kang Ai injection + conventional chemotherapy on tumor markers, apoptotic molecules and immune response in patients with advanced non-small cell lung cancer (NSCLC). Methods: Patients diagnosed as advanced NSCLC in our hospital during March 2015 - October 2017 were randomly divided into the experimental group receiving Kang Ai injection + conventional chemotherapy and the control group receiving conventional chemotherapy. The contents of tumor markers, apoptotic molecules and immunologic cytokines in serum and the contents of immune cells in peripheral blood were determined before and after chemotherapy. Results: after chemotherapy, the content of CEA, CYFRA21-1, SCC-Ag, GDF15 and Livin in the serum of the two groups decreased significantly, and the content of PDCD5, P53 and Bax increased significantly, and the content of CEA, CYFRA21-1, SCC-Ag, GDF15, Livin in the serum of the experimental group were lower than those of the control group, and the content of PDCD5, P53 and Bax were higher than those of the control group;the content of CD3+ and CD4+ cells in peripheral blood and the content of IFN-γ, IL-2 in serum of control group significantly decreased, whereas the content of CD8+ cells in peripheral blood and the content of IL-4, IL-5 in serum significantly increased after chemotherapy;while the content of CD3+ and CD4+ cells in peripheral blood and the content of IFN-γ, IL-2 in serum of experimental group significantly increased, whereas the content of CD8+ cells in peripheral blood and the content of IL-4, IL-5 in serum significantly decreased after chemotherapy. Conclusion: Kang Ai injection + conventional chemotherapy in the treatment of advanced NSCLC can more significantly decrease the serum tumor markers, regulate the secretion of apoptotic molecules and anti-tumor immune response than conventional chemotherapy.

Preparation of Fluoroalkyl End-Capped Oligomer/Cyclodextrin Polymer Composites: Development of Fluorinated Composite Material Having a Higher Adsorption Ability toward Organic Molecules

Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(CH2CHSi(OMe)3)n-RF;RF = CF(CF3)OCF7, n = 2, 3;RF-(VM)n-RF] was applied to the preparation of fluoroalkyl end-capped vinyltrimethoxysilane oligomer/α-, β-, γ-cyclodextrin polymers (α-, β-, γ-CDPs) composites [RF-(VM-SiO2)n-RF/α-, β-, γ-CDPs] by the sol-gel reaction of the corresponding oligomer in the presence of the α-, β-, γ-CDPs under alkaline conditions. The RF-(VM-SiO2)n-RF/α-, β-, γ-CDPs composites thus obtained were found to give a good dispersibility toward the traditional organic media except for water, and were applied to the surface modification of glass to provide a sueperoleophilic/superhydrophobic characteristic on the modified surface, although the corresponding RF-(VM-SiO2)n-RF nanocomposites can give a usual oleophobic/superhydrophobic property on the surface. These composites powders were also found to be applicable to the packing material for the column chromatography to separate the mixture of oil/water and the water in oil (W/O) emulsions. More interestingly, these composite powders were found to have a higher adsorption ability toward not only low-molecular weight aromatic compounds such as bisphenol A and bisphenol AF but also volatile organic compounds, compared to that of the pristine α-, β-, γ-CDPs.

Isolation of a small molecule with anti-MRSA activity from a mangrove symbiont Streptomyces sp.PVRK-1 and its biomedical studies in Zebrafish embryos

Objective:The aim of the present study was to isolate the anti-MRSA(Methicillin Resistant Staphylococcus aureus)molecule from the Mangrove symbiont Streptomyces and its biomedical studies in Zebrafish embryos.Methods:MRSA was isolated from the pus samples of Colachal hospitals and confirmed by amplification of mecA gene.Anti-MRSA molecule producing strain was identified by!6s rRNA gene sequencing.Anti-MRSA compound production was optimized by Solid State Fermentation(SSF)and the purification of the active molecule was carried out by TLC and RP-HPLC.The inhibitory concentration and LC_(50)were calculated using Statistical software SPSS.The Biomedical studies including the cardiac assay and organ toxicity assessment were carried out in Zebraiish.Results:The bioactive anti-MRSA small molecule A,was purified by TLC with Rf value of 0.37 with 1.389 retention time at RP-HPLC.The Inhibitory Concentration of the purified molecule A_2 was 30μg/mL but,the inhibitory concentration of the MRSA in the infected embryo was 32-34μg/mL for TLC purified molecule A,with LC_(50)mean value was61.504μg/mL.Zebrafish toxicity was assessed in 48-60μg/mL by observing the physiological deformities and the heart beat rates(HBR)of embryos for anti MRSA molecule showed the mean of 41.33-41.67 HBR/15 seconds for 40μg/mL and control was 42.33-42.67 for 15 seconds which significantly showed that the anti-MRSA molecule A_2 did not affected the HBR.Conclusions:Anti-MRSA molecule from Streptomyces sp PVRK-I was isolated and biomedical studies in Zebrafish model assessed that the molecule was non toxic at the minimal inhibitory concentration of MRSA.

Prevalence of hepatitis B and C markers among refugees in Athens

AIM: To assess the prevalence of hepatitis B and C serological markers in a population of refugees living in Athens.METHODS: One hundred and thirty refugees (81 males and 49 females, mean age ±SD: 31.7±8 years) were included in the study. The hepatitis B virus surface antigen (HBsAg),the hepatitis B virus core antibody (anti-HBc) and the hepatitis C virus antibody (anti-HCV) were detected using a third-generation immunoassay.RESULTS: Twenty individuals (15.4%) were HBsAg positive and 69 (53.1%) were anti-HBc positive. The prevalence of HBsAg and anti-HBc was higher among refugees from Albania and Asia (statistical significant difference, P＜0.008 and P＜0.001 respectively). The prevalence of these markers was found irrelevant to age or sex. Anti-HCV was detected in the serum of 3 individuals (2.3 %). No differences among age, sex or ethnicity regarding anti-HCV prevalence were found.CONCLUSION: It can be concluded that refugees living in Athens are an immigrant population characterized by a high incidence of HBV infection. The prevalence of HBV markers is higher among refugees from Albania and Asia. It is therefore believed that the adherence to general precautions and the initiation of HBV vaccination programs will be necessary in the future, especially in these communities.Although the prevalence of HCV infection seems to be relatively low, extended epidemiological surveys are needed to provide valid results.

荧光相关光谱单分子检测系统的研究

基于激光共焦构型,构建了一套高灵敏度和高稳定性的荧光相关光谱单分子检测系统。采用高数值孔径物镜使激光束高度聚焦,并用同一物镜收集样品的荧光,单光子计数器用于实时记录荧光信号。优化系统保持物镜焦点、针孔以及单光子计数器光敏区高度同轴。采用60×1.2(NA)的水浸物镜及直径为160μm的针孔得到的检测系统结构参数为ω0和z0分别为0.42μm和1.33μm,照射微区的体积为1.3fL。单个RhodamineGreen分子可获得13倍的信噪比。用该系统获得了小分子和生物大分子(DNA片段和蛋白质)的高质量荧光相关图谱,成功实现了单个分子的检测。

骨代谢生化指标临床应用专家共识(2020)

骨代谢生化指标包括钙磷代谢调节指标、骨形成标志物、骨吸收标志物、激素与细胞因子。骨代谢生化指标分别来源于骨、软骨、软组织、皮肤、肝、肾、小肠、血液及内分泌腺体等,是由成骨细胞或破骨细胞分泌的酶和激素,以及骨基质的胶原蛋白或非胶原蛋白代谢产物。骨代谢生化指标可及时反映骨转换状态,灵敏度高、特异性强,用于骨质疏松诊断分型、预测骨折风险、抗骨质疏松治疗疗效评价,以及代谢性骨病的诊断与鉴别诊断。并且在骨质疏松流行病学、发病机制、骨质疏松药物的研究方面具有重要的临床意义。本文对《骨代谢生化指标临床应用专家共识(2019)》进行了修订,共有41处修改,保留了经典文献,删减了部分内容,增加了近三年的文献,收集整理了骨代谢指标实验检测参考范围。

利用分子标记辅助选择聚合水稻基因Xa21和Pi9(t)

通过有性杂交和田间多代选育,利用分子标记辅助选择和田间/温室抗性鉴定,将广谱高抗白叶枯病的Xa21基因和高抗稻瘟病的Pi9(t)基因聚合到同一品系中,获得双基因纯合且农艺性状稳定的株系。用中国7个和安徽省流行白叶枯病病菌以及多个稻瘟病小种进行抗病性鉴定,结果表明:双抗基因系同时抗白叶枯病和稻瘟病,抗性级别为HR-R,抗谱与供体亲本一致,抗性水平基本相当。室内考种结果显示:双抗基因系间株高变异较大;单株有效穗比两亲本弱;结实率和千粒重明显优于Xa21基因的供体M12,与Pi9(t)基因的供体亲本75-1-127相当。

Clinical assessment and identification of immuno-oncology markers concerning the 19-gene based risk classifier in stage Ⅳ colorectal cancer

BACKGROUND Genomic profiling of tumors has contributed to the understanding of colorectal cancer(CRC), facilitating diagnosis, prognosis and selection of treatments,including targeted regimens. A report suggested that a 19-gene-based risk classifier(TCA19) was a prognostic tool for patients with stage III CRC. The survival outcomes in patients with stage IV CRC are still poor and appropriate selection of targeted therapies and immunotherapies is challenging.AIM To assess clinical implication of TCA19 in patients with stage IV CRC, and to identify TCA19 with involvement in immune-oncology.METHODS A retrospective review of the medical records of 60 patients with stage IV CRC was conducted, assessing clinicopathological variables and progression-free survival(PFS). TCA19 gene expression was determined by quantitative polymerase chain reaction(qPCR) in matched normal and tumor tissues taken from the study cohort. Expression of potential immune-oncology regulatory proteins and targets was examined by immunohistochemistry(IHC), western blot, immunofluorescence staining in tissues from a validation cohort of 10 patients, and in CRC cell lines co-cultured with monocyte in vitro.RESULTS In the patients with TCA19 score higher than the median, the PFS rates of eight patients who received the targeted regimens were significantly higher than the PFS rates of four patients who received 5-fluorouracil-based regimen(P = 0.041).In multivariate analysis, expression of signaling lymphocytic activation molecule family, member 7(SLAMF7) and triggering receptor expressed on myeloid cells 1(TREM1) was associated with PFS in the 60-patient cohort. After checking another 10 validate set, the expression of the IHC, the level of real-time qPCR,and the level of western blot were lower for SLAMF7 and higher for TREM7 in primary and metastatic tumors than in normal tissues. In CRC cells expressing SLAMF7 that were co-cultured with a monocytic cell line, levels of CD 68 and CD73 were significantly lower at day 5 of co-culture than at day 0.CONCLUSION The TCA19 score might be prognostic for target-regimen-specific PFS in stage IV CRC. Down-regulation of SLAMF7 and up-regulation of TREM1 occur in primary and metastatic tumor tissues.

Small molecule inhibitor DDQ-treated hippocampal neuronal cells show improved neurite outgrowth and synaptic branching

The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration.Axons and dendrites,sometimes referred to as neurites,are extensions of a neuron's cellular body that are used to start networks.Here we explored the effects of diethyl(3,4-dihydroxyphenethylamino)(quinolin-4-yl)methylphosphonate(DDQ)on neurite developmental features in HT22 neuronal cells.In this work,we examined the protective effects of DDQ on neuronal processes and synaptic outgrowth in differentiated HT22cells expressing mutant Tau(mTau)cDNA.To investigate DDQ chara cteristics,cell viability,biochemical,molecular,western blotting,and immunocytochemistry were used.Neurite outgrowth is evaluated through the segmentation and measurement of neural processes.These neural processes can be seen and measured with a fluorescence microscope by manually tracing and measuring the length of the neurite growth.These neuronal processes can be observed and quantified with a fluorescent microscope by manually tracing and measuring the length of the neuronal HT22.DDQ-treated mTau-HT22 cells(HT22 cells transfected with cDNA mutant Tau)were seen to display increased levels of synaptophysin,MAP-2,andβ-tubulin.Additionally,we confirmed and noted reduced levels of both total and p-Tau,as well as elevated levels of microtubule-associated protein 2,β-tubulin,synaptophysin,vesicular acetylcholine transporter,and the mitochondrial biogenesis protein-pe roxisome prolife rator-activated receptor-gamma coactivator-1α.In mTa u-expressed HT22 neurons,we observed DDQ enhanced the neurite characteristics and improved neurite development through increased synaptic outgrowth.Our findings conclude that mTa u-HT22(Alzheimer's disease)cells treated with DDQ have functional neurite developmental chara cteristics.The key finding is that,in mTa u-HT22 cells,DDQ preserves neuronal structure and may even enhance nerve development function with mTa u inhibition.

1-苯胺基萘-8-磺酸盐在各种固体基质中发光特性的研究

1-苯胺基萘 - 8-磺酸盐 (ANS)在不同的固体基质中发光特性的研究发现 :(1 ) ANS分子发射峰位置与在甲醇溶液中相比 ,发生明显的蓝移 ,可能是由于约束在固体基质中的荧光分子的运动受到一定的限制而接近单分子发光的行为。与纯粉末 ANS荧光相比 ,发生红移。ANS在极性的滑石基质中 ,发射峰移向更短的波长 ,在非极性的石蜡基质中移向更长的波长 ,反映固体基质微观环境的变化。 (2 ) ANS分子荧光寿命明显缩短 ,主要原因是在固体基质中 ,荧光发射速率常数 kf 增大。 (3) ANS分子相对量子产率明显增大 ,荧光分子运动受限 ,减弱分子之间的相互作用 ,减小了由于碰撞引起的猝灭 ,分子结构刚性增强。该结果对于研究固体基质的物化性质、探讨光化学反应中能量转移现象具有重要意义。

天敌对烟粉虱捕食作用的SCAR标记检测

以烟粉虱和捕食性天敌为研究对象,采用特征序列扩增区域(SCAR)标记法,通过对目的片段的克隆与测序设计烟粉虱特征片段扩增引物,检验该引物的种、虫态及性别特异性,并利用该引物检测捕食性天敌对棉田烟粉虱的捕食作用。研究结果表明,利用SCAR标记法获得了长度为347bp的烟粉虱特异性片段(GenBank登录号为AY841800),根据此片段的碱基序列设计烟粉虱特异引物1对TB-F/TB-R94585,其扩增片段约为240bp;种特异性检验结果表明,该引物只对烟粉虱具有扩增能力,对温室粉虱及其它相关种类不具有扩增效果;同时该引物对不同虫态、不同性别的烟粉虱具有同样的扩增效应。田间检测结果表明,同种天敌昆虫幼体捕食作用检出率高于成虫;在所检测的4类群9种捕食性天敌中,龟纹瓢虫幼虫、异色瓢虫幼虫、草蛉幼虫及东亚小花蝽成虫和蜘蛛对烟粉虱捕食作用的检出率高于50%。