4个品种鸡Toll样受体4基因第2内含子的多态性分析

本研究采用PCR-SSCP和DNA测序的方法检测了4个品种鸡(仙居鸡、白耳鸡、清远麻鸡和安卡鸡)Toll样受体4(Toll-like receptor 4,TLR4)基因第2内含子的单核苷酸多态性。结果表明,4个品种鸡TLR4基因的第2内含子上均发现了G1894C的突变,共产生了AA、AB和BB 3种基因型,4个品种鸡该位点的多态信息含量(PIC)分别为0.570、0.597、0.583和0.588,均属于高度多态性,且处于Hardy-Weinberg平衡状态(P>0.05);4个品种鸡G1894C多态位点的基因型在感染鸡白痢沙门氏菌阳性组和阴性组间的分布差异均不显著(P>0.05);G1894C多态位点在仙居鸡与白耳鸡2个品种间基因型分布差异极显著(P<0.01)。     

12个地方品种鸡TLR4基因多态性分析

为了探究我国地方鸡种TLR4基因的多态性和群体遗传特性,本研究采用PCR-SSCP及DNA测序方法,对我国12个地方品种鸡TLR4基因部分序列的单核苷酸多态性进行分析.结果显示,在所有鸡种TLR4基因的第二内含子上均发现了G1894C的突变.除了固始鸡极显著偏离Hardy-Weinberg平衡(P＜0.01)外,其他品种均处于Hardy-Weinberg平衡(P＞0.05).12个鸡品种该位点的多态信息含量均属于高度多态,其中皖南三黄鸡该位点的多态信息含量和杂合度最高,北京油鸡次之,文昌鸡最低;12个品种间的基因型分布存在极显著差异(P＜0.01).本研究表明,中国地方鸡种TLR4基因G1894C位点多态丰富,为深入开展鸡TLR4基因抗病育种的研究提供了一定的理论基础.     

鸡催乳素基因外显子5的多态性及Taq I位点与边鸡繁殖性状的相关性分析

研究采用DNA池直接测序法寻找边鸡催乳素基因外显子5区域的多态位点.用PCR-RFLP技术检测发现的Taq I位点在边鸡以及3个对照鸡品种(京海黄鸡、尤溪麻鸡和AA鸡)中的单核苷酸多态性,并与边鸡的繁殖性状进行相关性分析.结果表明:在外显子5区域检测到3个突变位点(C5749T、T5821C、C25956T).T5821C位点经Taq I酶切显示3种基因型(AA、AB和BB).在4个鸡品种中都以A等位基因为优势等位基因.最小二乘分析表明,边鸡3种基因型个体的繁殖性状无显著差异(P>0.05).     

鸡催乳素基因外显子5的多态性及Taq Ⅰ位点与边鸡繁殖性状的相关性分析

研究采用DNA池直接测序法寻找边鸡催乳素基因外显子5区域的多态位点。用PCR-RFLP技术检测发现的Taq I位点在边鸡以及3个对照鸡品种(京海黄鸡、尤溪麻鸡和AA鸡)中的单核苷酸多态性,并与边鸡的繁殖性状进行相关性分析。结果表明:在外显子5区域检测到3个突变位点(C5749T、T5821C、C5956T)。T5821C位点经Taq I酶切显示3种基因型(AA、AB和BB)。在4个鸡品种中都以A等位基因为优势等位基因。最小二乘分析表明,边鸡3种基因型个体的繁殖性状无显著差异(P>0.05)。     

不同鸡种沙门菌感染率比较分析

试验采用血清平板凝集法,对江苏省某种鸡场中白耳鸡、仙居鸡、安卡鸡和清远麻鸡4个品种的沙门菌天然感染情况进行了评估。结果显示,公鸡中肉用型安卡鸡对2种沙门菌病的感染率最高,蛋用型品种居中;母鸡中蛋用型品种对2种沙门菌病的感染率最高,肉用型品种居中;不同品种、不同性别以肉蛋兼用型的清远麻鸡感染带菌率最低。     

脂肪型脂肪酸结合蛋白基因多态性与鸡肉品质性状的关系研究

采用PCR-SSCP技术分析了A-FABP基因在北京油鸡、矮脚鸡、泰和乌骨鸡、崇仁麻鸡、鹿苑鸡、霞烟鸡等6个地方品种鸡和AA肉鸡中的多态性,发现的3个多态位点的基因型频率和等位基因频率在不同品种之间存在显著差异。测序分析表明：多态位点的产生分别是由碱基C→T、G→A以及C→T的变异引起的。在北京油鸡、矮脚鸡群体中对各多态位点不同基因型与体重、肌内脂肪、腹脂率等脂肪相关性状进行关联分析,结果显示不同基因型间在部分肉品质相关性状上差异显著。     

鸡TLR4突变位点对蛋白结构的影响及其遗传多样性

为研究TLR4不同SNPs位点对TLR4蛋白结构的影响及其在不同鸡种中的遗传变异,采用直接测序法发掘TLR4基因外显子中的SNPs,分析每个SNP位点对TL尺4蛋白结构的影响,并检测对蛋白结构影响较大的两位点在不同鸡种中的遗传多样性。结果表明,在7个鸡群中共发现了17个SNPs;C77T和G247A位点对TLR4蛋白功能影响较大;C77T位点在汶上芦花鸡偏离Hardy—Weinberg平衡,在其它4个地方鸡种和2个商业品种都处于Har—dy—Weinberg平衡,其多态信息含量在寿光鸡最高;G247A位点在5个地方鸡种中均处于Hardy—Weinberg平衡状态,而在两个商业品种偏离Hardy—Weinberg平衡,其多态信息含量在寿光鸡最低。本研究表明,TLR4基因C77T和G247A位点在7个鸡群中具有不同程度的遗传多样性,推测与该基因的功能存在相关。     

思州鸡BMP15基因第1外显子多态性及其与蛋品质的关联分析

研究旨在探讨思州鸡骨形态发生蛋白15(BMP15)第1外显子多态性及其与蛋品质的相关性。采用PCR产物直接测序法检测思州鸡BMP15基因第1外显子测序,将测序结果用DNAStar软件校正;利用Excel 2007统计基因型频率数据,并进行卡方适合性检验;通过SPSS 18.0软件对BMP15基因不同基因型与思州鸡蛋品质间的关联性进行分析。结果显示,思州鸡BMP15基因第1外显子存在4个SNPs位点:397C/T、473A/G、603C/T和612C/T,均处于Hardy-Weinberg非平衡状态(P0.05);397C/T和603C/T位点的多态信息含量(PIC)分别为0.3488和0.3299,属于中度多态(0.25PIC0.5),473A/G与612C/T位点的PIC分别为0.1527和0.2075,属于低度多态(PIC0.25)。关联性分析结果表明,397C/T位点对思州鸡蛋白高度、哈氏单位、蛋黄重均有显著影响(P0.05);473A/G、603C/T位点对思州鸡蛋品质指标均无显著影响(P0.05);612C/T位点对思州鸡蛋长径有显著影响(P0.05),提示BMP15基因第1外显子对鸡蛋品质中蛋白高度、蛋长径具有较大的遗传效应。结果表明,BMP15基因可能是影响思州鸡蛋品质的基因之一,可作为思州鸡蛋白高度、蛋长径等蛋品质性状的分子标记。     

新广黄鸡MCEE基因多态性分析

为探讨MCEE基因多态性及其作为新广黄鸡生长性状遗传标记的可能性,对新广黄鸡进行MCEE基因多态性检测分析。采用Sanger测序法对MCEE基因的CDS和3′UTR区进行单核苷酸多态性(Singer nucleotide polymorphism,SNP)检测,并分析其对新广黄鸡生长性状的影响。结果表明:新广黄鸡MCEE基因的CDS区检测到3个SNP位点,分别为gC4715T、gT4734C和g C4925T。其中:g T4734C为错义突变,导致pSer 34Pro改变;3′UTR区检测到4个SNP突变位点,分别为g G8959A、g A8979G、g G9001C和g C9082T。MCEE基因CDS区3个SNP位点均表现为野生型基因型频率所占比重较高,属于低度多态,遗传变异较小;3′UTR区的4个SNP位点中,g A8979G位点表现为杂合型基因型频率所占比重较高,其余3个位点均表现为野生型基因型频率所占比重较高。MCEE基因3′UTR区的g G8959A、g A8979G和g C9082T三个SNP位点均属于中度多态,遗传差异较大。MCEE基因3′UTR区的g A8979G突变位点显著影响28日龄新广黄鸡体重(P0.05)。MCEE基因其它突变位点与体重无显著性相关。本研究初步揭示了鸡MCEE基因多态性及其与新广黄鸡体重之间的相关性,其对鸡生长性状的遗传效应有待进一步扩大样本量和品种进行验证并深入研究其对MCEE基因表达的影响。     

鸡Camk2d基因外显子15的SNP发现、检测及与经济性状的关联分析

克隆了鸡Camk2d基因的部分片段并发现Camk2d基因第15外显子51bp处有一C→T碱基转换的沉默突变,该突变位点具有VspI酶切多态,通过PCR-RFLP技术对我国乌骨鸡、鹿苑鸡、固始鸡、白耳鸡、仙居鸡、斗鸡和大骨鸡等7个不同地方品种鸡进行了基因型检测。结果表明:在7个品种中存在3种基因型(CC、CT、TT),χ2检验显示在各品种间基因型存在不同差异。同时在藏鸡,隐性白羽鸡,杂交鸡(藏♂×隐♀)和75%血液藏鸡[藏♂×(藏♂×隐♀)♀]群体中进行了基因-性状关联分析,结果表明,该SNP位点与腹脂存在极显著相关(P<0.01),与肌肉pH值显著相关(P<0.05)。     

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.