鹅LXRα基因的克隆及填饲对其mRNA水平的影响

为了研究填饲对LxRα mRNA表达水平的影响,本试验以四川白鹅和朗德鹅为试验对象,通过RT-PCR方法克隆了鹅肝脏X受体α(LXRα)基因部分序列,并采用SYBR-Green法研究了填饲对LXRα基因在肝脏和脂肪组织中转录水平的影响.结果获得了1005 bp的鹅LXRα部分序列,且与其它物种有较高的相似性,但存在8个氨基酸变异位点.LXRα基因在肝脏、腹脂和皮脂中都有表达,但在肝脏中的表达量最高.填饲引起鹅皮脂、腹脂和肝脏的LXRα mRNA表达丰度的显著增加.对照组中,LXRα在朗德鹅肝中的表达量高于四川白鹅(P<0.05),而在皮脂、腹脂中朗德鹅的表达量低于四川白鹅(P<0.05).填饲组,在肝和腹脂中LXRα的表达量四川白鹅显著高于朗德鹅(P<0.05),皮脂中表达量品种间差异不显著.填饲后LXRα mRNA表达丰度与皮脂、腹脂和肝脏的相对质量呈显著正相关,并且朗德鹅的相关性要强于四川白鹅.结论:填饲引起鹅肝脏和脂肪组织的LXRα mR-NA表达丰度的显著增加,填饲对LXRα mRNA表达的影响存在显著的品种差异.     

填饲对朗德鹅与四川白鹅体组成及部分血浆参数的影响

本试验通过对朗德鹅和四川白鹅单位体重填饲等量饲料,研究了填饲对两品种鹅体重、肝重率、腹脂率、胸肌率、腿肌率等体组成指标以及血浆极低密度脂蛋白(VLDL)、甘油三酯(TAG)、葡萄糖、胰岛素浓度等血浆参数指标的影响。结果表明,填饲后朗德鹅肝增重显著高于四川白鹅,但填饲所导致的四川白鹅皮脂率及腹脂率增长显著高于朗德鹅。填饲后四川白鹅与朗德鹅血浆中VLDL、TAG浓度极显著高于对照组,且四川白鹅血浆中VLDL、TAG浓度显著高于朗德鹅。结果表明,朗德鹅肝脏能更好利用食物中的碳水化合物合成脂类,且合成的脂类优先贮存在肝脏。四川白鹅肝脏合成的脂类贮存在脂肪组织的效率更高。     

鹅Perilipin基因部分片段的克隆、不同品种及填饲对组织mRNA表达水平的影响

本研究旨在克隆鹅围脂滴蛋白(Perilipin)基因,并探讨填饲对其在四川白鹅和朗德鹅肝脏中表达的影响,为从脂滴角度研究鹅肥肝分子机理提供依据。试验选取12只朗德鹅和12只四川白鹅为研究对象,通过RT-PCR方法扩增鹅Perilipin基因部分序列,采用实时定量技术研究了该基因在皮脂、腹脂、肝脏等10个组织中的表达情况,最后检测填饲后两品种鹅肝脏总脂质含量、甘油三酯(TG)水平、肝质量以及Perilipin基因表达变化。结果表明:获得的鹅Perilipin基因序列与原鸡的同源性最高,与哺乳动物的同源性也达到70%以上;从组织表达上看,该基因主要表达于腹脂和皮脂,而在其他组织几乎不表达;填饲引起鹅肝脏Perilipin mRNA表达丰度的极显著增加(P0.01),且与肝质量、肝内TG和总脂质呈显著正相关;此外,填饲导致其在朗德鹅肝脏中的表达丰度显著高于四川白鹅(P0.05)。结果提示:填饲会引起Perilipin mRNA在鹅肝脏中表达丰度的极显著增加(P0.01),且其增加幅度存在着品种间差异(P0.05)。     

朗德鹅和朗德鹅×太湖鹅的产肝性能研究

朗德鹅和朗德鹅×太湖鹅(简称朗太鹅)经过21天的填肥,体重分别达到6.74千克、5.22千克,是填肥开始时的1.54倍、1.55倍,肥肝重分别达到0.600千克、0.248千克,腹脂重分别达到0.287千克,0.319千克,体重和肥肝重在这两种鹅间差异显著,而腹脂重不显著。填肥结束时,期德鹅和朗太鹅的血浆TG(甘油三酯 TCH(总胆固醇)PL(磷脂)VLDL(极低密度脂蛋白)浓度均显著高于填肥开始时的浓度。填肥开始时血浆AKP(碱性磷酸酶)活性、血浆TCH、PL、VLDL浓度和填肥结束时血浆AKP、LDH(乳酸脱氩酶)活性、血浆TG、TCH、PL、VLDL浓度在两种鹅间差异显著,血液生化指标在填肥开始和结束间的显著差异在一定程度上说明了填肥使机体内的脂肪代谢明显增强,而血液生化指标在两种鹅间的显著差异则从生化水平上体现了各自的遗传特点,至于这种遗传特点是否与产肝性能的优劣有内在联系,还有待进一步研究。     

皖西白鹅与朗德鹅脂肪基因表达的比较

选择90日龄的皖西白鹅和朗德鹅各20只,取其腹腔脂肪,用半定量逆转录多聚酶链式反应(RT-PCR)的方法,以β-actin为内标,比较分析腹脂中的脂联素(adiponectin,ADP)、脂联素-2型受体(adiponectin receptor 2,ADPR2)、瘦素(leptin, LEP )mRNA的表达,并与腹脂重进行相关性分析,采用ELISA方法测定两种鹅血液中ADP水平.结果表明:皖西白鹅的腹脂重和腹脂率与朗德鹅无显著差异;皖西白鹅腹脂ADP mRNA的表达显著高于朗德鹅(P<0.05),而ADPR2显著低于朗德鹅(P<0.05),LEP mRNA表达在两品种间无显著差异;腹脂重与ADP、AdipoR2、LEP mRNA的表达无显著的相关性;皖西白鹅血液中脂联素含量显著低于朗德鹅(P<0.05).结果提示:①鹅腹脂中ADP及其受体的基因表达存在品种差异;②鹅腹脂分泌的ADP可能不是血液中ADP的主要来源.     

鹅ACSL1基因克隆及其在鹅肥肝形成中作用的初步研究

本研究旨在克隆鹅长链酯酰辅酶A合成酶1(ACSL1)基因,并研究其在填饲诱导鹅肥肝形成中的作用,为揭示ACSL1在鹅肥肝形成过程中的作用提供依据。以前期抑制消减杂交文库筛选的部分ESTs序列为基础,通过RT-PCR扩增鹅ACSL1基因CDS、并用实时定量等技术检测该基因在皮脂、腹脂、肝脏等10个组织中的表达情况及填饲对其在肝脏中表达的影响,同时与填饲后鹅肝脏总脂质、甘油三酯(TG)、肝质量等指标进行相关分析。结果发现:鹅ACSL1基因CDS全长2100bp,编码699个氨基酸。保守结构区预测发现,其蛋白质跟其他物种一样,也存在2个保守功能区(ATP/AMPmotif和FACSmotif)和1个跨膜结构域,它与鸡、牛、人、小鼠ACSL1基因的同源性分别为93%、80.4%、78.5%、77.3%;该基因主要表达于腹脂、皮脂、肝脏,而在其他组织表达相对较低;填饲能引起ACSL1mRNA在鹅肝脏的表达丰度极显著增加(P0.01),且与肝质量、肝内TG和总脂质呈显著正相关;同时,填饲导致其在朗德鹅肝脏中的表达丰度显著高于四川白鹅(P0.05)。结果提示:填饲引起ACSL1mR-NA在鹅肝脏中极显著增加(P0.01),且其增加幅度存在着品种间差异(P0.05)。     

鹅MAPK14基因部分序列克隆及填饲对其mRNA丰度的影响

为研究填饲对鹅丝裂原活化蛋白激酶14(MAPK14)mRNA表达水平的影响,本实验克隆了鹅MAPK14部分编码区序列,并用荧光定量PCR方法检测了填饲对四川白鹅和朗德鹅肝组织MAPK14基因表达量的影响。结果表明:获得鹅MAPK14基因cDNA 951 bp序列,可编码316个氨基酸残基。经分析,鹅MAPK14部分核苷酸序列与原鸡MAPK14基因的同源性为94.8%,对应的氨基酸同源性为99.7%;荧光定量PCR检测发现,无论在对照组还是填饲组,四川白鹅的MAPK14表达量均高于朗德鹅,填饲能显著上调MAPK14 mRNA在2个鹅品种中的表达丰度。结果提示,填饲能够引起鹅肝组织中MAPK14表达丰度显著增加,且该影响存在显著的品种差异。     

开填日龄对朗德鹅脂肪沉积和生长性能的影响

试验旨在研究不同开填日龄对朗德鹅脂肪沉积与生长性能的影响。试验选取同条件饲养的70和120日龄朗德鹅各60只作为研究对象,在相同条件下开展填饲试验,正式填饲至14 d时称量试验鹅体重,试验结束时取肝脏并测量各屠宰指标以及脂肪沉积能力。结果显示:(1) 70日龄开填朗德鹅体重较120日龄开填朗德鹅低235.71 g,肝脏成熟时屠宰重基本接近,整个填饲期,70日龄开填朗德鹅增重与120日龄开填朗德鹅无显著差异。(2) 70日龄和120日龄开填朗德鹅试验结束时肝重差异显著(P<0.05),但70日龄开填朗德鹅料肝比(26.18)显著低于120日龄朗德鹅(30.43)(P<0.05)。(3)脂肪沉积方面,70日龄和120日龄开填朗德鹅腹脂重及腹脂重占体增重比例无显著差异,但120日龄组朗德鹅的肠脂重占体增重比例显著高于70日龄组(P<0.05)。(4) 70日龄开填朗德鹅屠宰后头重、小翅重、大翅重、肌胃重和鹅掌重与120日龄试验鹅差异不显著(P>0.05)。结果表明:70日龄开填朗德鹅肥肝重低于120日龄朗德鹅,但其填饲期增重多,料肝比也较低,具有更好的填饲效率。120...     

皖西白鹅血脂性状研究及与朗德鹅的比较

随机选择90日龄皖西白鹅和朗德鹅各20只,采集血样用于血液中脂肪指标的测定,完整采集肝脏组织并计算肝重率。血脂包括甘油三酯(TG)、总胆固醇(TCHO)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)。结果显示:皖西白鹅血清中TG、TCHO、HDL-C水平显著高于朗德鹅(P<0.05);皖西白鹅的肝重率极显著高于朗德鹅(P<0.01)。相关性分析结果显示:两种鹅血清中TCHO、LDL-C、HDL-C含量间都呈极显著正相关(P<0.01);朗德鹅的肝重率与血清中TG的含量呈极显著正相关(P<0.01)。结果提示:两种鹅对于胆固醇的代谢机制相类似,而在肝脏的生长和TG合成代谢方面表现出品种差异。     

填饲对朗德鹅生长参数和代谢的影响

为研究填饲对朗德鹅生长参数和代谢的变化及程度以及生长参数与代谢参数之间的相关性,将30只90日龄朗德鹅公鹅随机平均分为2组笼养.填饲组高频填饲高能玉米,对照组自由采食普通饲料.21 d后测量体重(活重)、肝重、腹脂重;检测血脂和血糖等指标.填饲组较对照组体重、肝重、腹脂重极显著增高(P＜0.01),血糖显著增高(P＜0.05),血甘油三酯(P＜0.01)、总胆固醇和游离脂肪酸(P＜0.05)显著增高;填饲组体重与腹脂重显著正相关,总胆固醇与体重显著负相关.强制填饲后朗德鹅脂代谢、糖代谢均发生严重紊乱,多个参数的相关性较对照组显著改变.     

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.