利用miRNA芯片筛选不同月龄香猪肝脏中差异表达的miRNA

为研究miRNA在香猪发育时期的调控功能,试验对3和7月龄香猪肝脏组织中存在表达差异的miRNA进行了筛选。提取3和7月龄香猪肝脏组织总RNA,通过与miRNA芯片杂交,经统计学分析,以变化倍数≥2倍（P<0.05）为阈值,筛选3和7月龄香猪肝脏中表达丰度差异的miRNA,并运用实时荧光定量PCR进行验证。结果发现,与3月龄相比,7月龄香猪肝脏中有11条miRNA表达下调和9条miRNA表达上调,下调倍数最多的是miR-27b,上调倍数最多的是miR-155。对选取的4条差异表达的miRNA进行实时荧光定量PCR反应,结果显示,4条miRNA表达变化趋势与芯片结果一致。本研究结果表明,不同月龄香猪肝脏中的miRNA表达丰度有差异,其中一些可能参与了机体生长发育时期肝细胞的脂肪代谢过程。     

传染性法氏囊病病毒感染细胞内源性microRNA表达差异分析

细胞内源性microRNA（miRNA）在宿主与病原相互作用过程中发挥着重要的调节功能。为了分析细胞内源性miRNA与传染性法氏囊病病毒（IBDV）的相互作用,用IBDV弱毒和强毒分别感染鸡胚成纤维细胞（CEF）和SPF鸡,24h后,取感染CEF和法氏囊组织,提取细胞总RNA,用Hy3/Hy5双色荧光标记,与miRNA芯片杂交,进行芯片内标准化、芯片间标准化、表达差异比较以及聚类分析。结果显示：在IBDV弱毒感染的CEF中,有17个细胞内源性miRNA表达上调,17个miRNA表达下调;在IBDV强毒感染的鸡法氏囊组织细胞中,有30个细胞内源性miRNA表达上调,18个miRNA表达下调。根据表达差异显著的miRNA序列设计引物,用荧光定量RT-PCR方法验证芯片检测结果,2种方法的检测结果一致。结果表明,IBDV感染可诱导细胞内源性miRNA表达变化,这些上调或下调的miRNA能调控细胞内多种代谢和信号传导途径发生异常,引起细胞及组织器官发生病理学变化。     

调控香猪繁殖候选miRNA筛选

研究旨在从香猪卵巢small RNA测序数据中挖掘调控香猪繁殖的microRNA （miRNA）,解析miRNA调控香猪卵巢功能及繁殖性状的分子机制,对于猪的遗传选育具有重要意义。研究选取发情期和间情期的香猪各4头,屠宰后取其卵巢组织,提取总RNA进行small RNA测序,利用生物信息学方法检测miRNA表达谱,筛选差异表达的miRNA,预测差异表达miRNA靶基因,并对靶基因进行GO功能富集和KEGG通路富集分析。结果显示,香猪卵巢组织中miRNA在染色体上呈不均匀分布,主要分布于1号染色体和X染色体上。香猪卵巢中共有627个已知猪miRNAs表达,其中有34个差异表达miRNAs,表达量前五的分别是miR-23、let-7i-5p、miR-103、miR-30e-5p和miR-1271-5p。GO功能分析结果显示,靶基因主要参与的生物学过程是细胞过程（cellular process）,主要分布于细胞（cell）,主要分子功能是结合（binding）;KEGG显著富集通路中,促性腺激素释放激素受体通路（gonadotropin-releasing hormone receptor pathway）、胰岛素样生长因子通路（IGF pathway）和表皮生长因子受体信号通路（EGF receptor signaling pathway）与卵母细胞的发育成熟相关,因此推测miR-23b、let-7i-5p、miR-103、miR-30e-5p和miR-1271-5p可能参与了香猪繁殖调控。本研究初步筛选出5个可能调控香猪繁殖性能的miRNAs,可为从分子水平提高香猪产仔数提供理论基础。     

原癌基因c-myc在塔里木马鹿茸不同生长期的表达

为探讨原癌基因c-myc对鹿茸生长的调控作用,选择3头成年塔里木马鹿生长期为30、60d的新鲜鹿茸,剖分成茸皮层、间充质细胞层、成软骨细胞层和软骨细胞层。首先用2种免疫组化的方法进行基因表达定位,然后通过荧光定量PCR技术对不同组织基因表达定量进行分析。结果显示：该基因在茸皮的毛囊内根鞘、毛母质和皮脂腺呈阳性反应,在动脉血管的环形平滑肌、真皮乳头层与表皮基部连接的基底层呈阳性反应。在静脉血管、神经和其他附属器反应均呈阴性。定量分析结果表明c-myc基因在不同生长阶段不同组织层均有表达。茸皮层从生长期30～60d,c-myc表达下调,而在其他3个组织中均上调表达;同一生长期茸皮和软骨层的表达量均高于间充质细胞层和成软骨层（P〈0.05）;不同生长期30、60d组织间基因的表达没有显著的变化。研究结果表明,c-myc基因在鹿茸快速生长期参与了茸皮的增殖与分化;在软骨组织中高表达特别是生长后期,说明原癌基因c-myc对马鹿茸软骨发育及骨形成有着一定调控作用。     

朗德鹅填肥期SCD1基因的表达及其相关miRNA的筛选

SCD1是位于内质网上的一类催化酶,在肝脏的脂质代谢及鹅肥肝形成中发挥重要作用。试验通过荧光定量PCR技术对填饲不同阶段(填饲7、14和19 d)朗德鹅肝脏中SCD1基因的表达进行了研究。结果发现:SCD1基因在填饲各阶段肝脏中表达量均高于对照组,且填饲19 d时,填饲组表达量极显著高于对照组(P0.01);通过测定填饲组各时期肝脏中棕榈油酸、油酸含量以及血液中甘油三酯和胆固醇含量发现,SCD1基因表达量与油酸、胆固醇、VLDL以及甘油三酯含量均呈显著正相关(P0.05);通过生物学软件预测SCD1的靶向miRNA并利用双荧光素酶报告系统在CHO细胞系中验证所筛选的3个miRNA,结果显示miR30b与miR-30a-5p为鹅SCD1基因可能的靶向miRNA,进一步研究发现miR-30b和miR-30a-5p在填饲组表达量均显著低于对照组(P0.05),表明miR-30b和miR-30a-5p可能通过对SCD1基因的调节作用影响鹅肝脏脂代谢过程。     

狂犬病病毒感染对宿主miR-29a和miR-124表达的影响及其靶基因分析

依据本实验室前期狂犬病病毒(RABV)感染小鼠原代神经元microRNA(miRNA)表达谱数据,选取表达显著上调的miR-29a和下调miR-124为研究对象,采用实时荧光定量PCR技术检测目的 miRNA在RABV感染前后的小鼠原代神经元和小鼠海马组织内的表达变化。运用TargetScan数据库预测目的 miRNA潜在的靶基因,并对靶基因进行了GO(Gene Ontology)注释描述、GO注释富集分析和信号通路富集分析,富集结果呈现出数个与神经功能相关的GO注释和信号通路。本研究结果提示miR-29a和miR-124可能参与了RABV感染所致的宿主神经功能异常。     

猪圆环病毒2型感染PK-15细胞差异表达miRNA和mRNA互作网络

旨在筛选猪圆环病毒2型感染猪肾上皮细胞(PK-15)后差异表达miRNA和mRNA,并探究miRNA和mRNA之间的互作关系。使用茎环定量PCR检测多个热点miRNA在PCV2感染组和未接种病毒组之间的差异表达水平以发现差异表达miRNA,分析PCV2感染后第12小时的蛋白质组学研究结果(GEO登录号:GSE71945)以获得差异表达mRNA,并分析差异表达miRNA和mRNA之间的互相作用关系。结果显示,在PCV2感染后第12小时miR-10b、miR-128、miR-155-5p、miR-21、miR-29b、miR-361-3p等表达量显著性变化,使用miRecords预测其靶基因,分别发现7 105、9 741、7 451、7 183、7 971、8 793个靶基因;PCV2感染后第12小时共有158个差异表达mRNA,分属于多种细胞结构成分并参与多条重要的细胞生物途径,且差异miRNA的靶基因和差异mRNA之间有大量的交集基因。上述结果表明,PCV2感染能导致细胞内多种miRNA差异表达,造成miRNA的靶基因表达紊乱,进而影响细胞正常的生命进程。     

塔里木马鹿鹿茸VEGF基因克隆及其在不同鹿茸组织中的表达研究

试验旨在从塔里木马鹿鹿茸顶端组织中克隆血管内皮生长因子（vascular endothelial growth factor,VEGF）的编码序列,分析其分子特性及其在鹿茸组织中的表达情况。本研究采用改良的Trizol法提取鹿茸顶端组织总RNA,以RT-PCR方法获得VEGF基因,回收纯化后连接到pMD18-T载体,转化大肠杆菌DH5α感受态细胞并鉴定,利用免疫组化法确定VEGF蛋白在塔里木马鹿鹿茸顶端组织茸皮层、间充质层和软骨层中的表达水平。结果显示,VEGF基因开放读码框（ORF）全长为648 bp,编码216个氨基酸。通过其序列比对和进化分析发现,塔里木马鹿茸中VEGF与人、牛、羊、猪的VEGF核苷酸序列同源性分别为98.75%、96.55%、97.58%和97.56%,其中与人VEGF同源性较高。免疫组化试验表明,塔里木马鹿VEGF蛋白在间充质、茸皮层和软骨中均有表达,但无明显表达差异。说明塔里木马鹿鹿茸可能会是人类研究再生医学和血管相关疾病的理想模型,同时,本研究为不同发育期塔里木马鹿鹿茸再生干细胞比较蛋白质组学研究提供了基础试验数据。     

原癌基因c-fos在塔里木马鹿茸组织中表达特性的研究

为探讨原癌基因c-fos对鹿茸生长的调控作用,采用3头成年塔里木马鹿Cervus elaphus生长期为30、60d的新鲜鹿茸,剖分成茸皮层、间充质细胞层、成软骨细胞层和软骨细胞层。首先用2种免疫组化的方法进行基因表达定位,然后通过荧光定量PCR技术对不同组织基因的表达进行定量分析。免疫组化分析结果表明,该基因在茸皮的毛囊内根鞘和毛母质及皮脂腺、动脉血管的环形平滑肌处呈阳性反应;真皮乳头层与表皮基部连接的基底层呈阳性反应。在静脉血管、神经和其他附属器反应均未观察到阳性细胞。在间充质细胞层、成软骨层和软骨层2种方法均没有观察到c-fos的阳性表达细胞。定量分析发现,c-fos基因在不同生长阶段不同组织层均有表达,且在茸皮的表达量显著的高于间充质细胞层,成软骨层和软骨层(P<0.05)。在同一生长期间充质细胞层、成软骨层和软骨层c-fos的表达量很低;生长30与60d比较,c-fos在间充质细胞层和成软骨层变化不大,在茸皮层和软骨层表现为下调表达。本研究表明c-fos基因在鹿茸快速生长期参与了茸皮干细胞的增殖与分化,并对成骨细胞的分化起着调控作用。     

3T3-L1前脂肪细胞中Ghrelin对miRNAs表达的影响

为探讨3T3-L1前脂肪细胞增殖分化过程中Ghrelin对microRNAs(miRNAs)表达的影响,将pcDNA3.1(+)-Ghrelin转染至3T3-L1前脂肪细胞,real-time PCR检测10种miRNA的表达变化,并对显著差异表达的miRNA进行生物信息学分析。结果显示,pcDNA3.1(+)-Ghrelin的表达明显上调,约是对照组的5倍;real-time PCR结果显示,miR-125b-5p(P0.05)表达显著上调,miR-21a-5p(P0.01)、miR-30c-5p(P0.05)、miR-181-5p(P0.01)表达显著下调;生物信息学分析结果显示,预测调节的1 062个靶基因与细胞的生长、分化和发育功能相关,核因子1b(Nfib)是其共同调节的重要潜在靶基因;丝裂原活化蛋白激酶(MAPK signaling pathway)和成脂基因信号通路是其调节差异最为显著的信号通路,与脂肪细胞的增殖和分化密切相关。结果表明,Ghrelin可通过调节miRNA的表达影响3T3-L1前脂肪细胞的增殖和分化。研究结果为进一步探讨Ghrelin发挥效应的分子调节机制和分子调控网络奠定了基础。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.