Relationships between traits of cow-calf pairs and a measure of partial efficiency

Angus cow-calf pairs (N = 114) were individually fed grass silage diets under conditions chosen to approximate nutrient intake under a free grazing, noncreep situation. Postfactum comparison with a subsequently conducted study on pasture indicated that the procedures used produced animal responses similar to those provided by a tall fescue pasture averaging 58% dry matter digestibility. Cow-calf pair efficiency was expressed as the ratio of estimated total digestible nutrient (ETDN) intake of the pair to calf weight at weaning. Initial cow weight per se was unrelated to pair efficiency. When considered jointly with calf weight at weaning, initial cow weight was unfavorably and calf weight was favorably related to pair efficiency. Calf age at weaning and milk production were favorably related to pair efficiency through their relationship with calf weight at weaning. Initial cow fat thickness, estimated ultrasonically, was not related to this measure of efficiency, indicating compensations between the year just completed and the next year in the relationship between cow fat thickness at weaning and pair efficiency. Mating schemes resulting in selection of relatively smaller females and larger males, within the variation available in a straightbred population, would be expected to alter the cow weight-calf weight ratio in a direction favorable to the component of efficiency defined in this study.     

Genetic parameters of ascites-related traits in broilers: effect of cold and normal temperature conditions

(1) Ascites syndrome is a growth-related disorder of broilers that occurs more often in fast-growing birds and at low temperatures. The objective of this study was to estimate genetic and phenotypic correlations among ascites-related traits measured either under cold or under normal temperature conditions, and to estimate genetic correlations between ascites-related traits measured under cold and normal conditions. (2) Several traits related to ascites were measured on more than 4000 chickens under cold conditions and on more than 700 chickens under normal conditions. (3) The heritability estimates for body weight (BW) measured under cold and normal conditions were 0.42 and 0.50, respectively, for haematocrit value 0.46 and 0.17, respectively, and for ratio of right to total ventricular weight 0.45 and 0.12, respectively. (4) The genetic correlation between BW and haematocrit value under cold conditions was -0.23 and between BW and ratio of right to total ventricular weight -0.27. Under normal conditions, however, these genetic correlations were 0.55 and 0.50, respectively. (5) These results demonstrate that the heritability estimates of ascites-related traits as well as genetic correlations between ascites-related traits and BW depend on the temperature conditions under which animals are kept. (6) Strong positive genetic correlations (around 0.8) were observed between total mortality, fluid in the abdomen and ratio of right to total ventricular weight under cold conditions. The genetic correlation between ratio of right to total ventricular weight under cold and normal conditions was 0.91. (7) These results suggest that the ratio of right to total ventricular weight measured under normal temperature conditions might serve as a good indicator trait for ascites.     

Al_2O_3-脱乙酰几丁质作为酶固定化载体的研究

Al2O3作核心的脱乙酰几丁质颗粒可用作酶固定化的载体。观察了脱乙酰几丁质的浓度、脱乙酰度和分子量对酶的固定化的影响。发现以浓度为2．0％、脱乙酰度为85．0％、分子量为1．34×106d的脱乙酰几丁质制得的载体用于固定化酶效果最好。所得固定化GOD具有较高的固定化酶活力、热稳定性和工作稳定性。     

热应激下鸡肝脏SFRP1和PDK4基因表达水平研究

为研究热应激条件下,鸡SFRP1和PDK4两个与代谢相关的基因在鸡肝脏组织中的差异表达,选取12只60日龄体重相近的黄羽肉母鸡,分为正常对照组(CL)、热应激反应组(HS)和热应激反应后的降温组(HF)3个处理组,并对这两个基因在三组肝脏组织中的表达水平进行荧光定量表达分析。结果表明,在热应激状态下,SFRP1和PDK4基因在肝脏中的表达均上调,且PDK4在对照组和热应激组间差异显著(P<0.05)。本研究结果还表明,当热应激反应后温度重新降至(25±1)℃时,SFRP1和PDK4在肝脏中的相对表达量均有不同程度的恢复,进一步说明这两个基因在热应激中发挥的作用。本研究为从分子机制分析热应激提供了相应的参考。     

驴骨胶原肽制备方法的初步建立及分子量检测

旨在建立驴骨胶原肽的制备方法,并对其分子量进行检测.以牛血清白蛋白为对照品,建立多肽含量和OD650 nm值的标准曲线方程;模拟人工胃液、肠液环境,以驴骨胶原肽一级、二级酶解产物多肽含量为评价指标,在筛选胃蛋白酶和胰蛋白酶最佳酶解时间和加酶量的基础上,采用二级生物酶解技术制备驴骨胶原肽;应用SDS-PAGE法对制备的驴...     

家蚕茧丝相关性状的性连锁QTLs定位与分析

家蚕的茧丝性状存在明显的性别差异。以茧丝性状成绩差异较大的家蚕品种兰10和菁松为亲本组配回交1代分离群体(BC1M),在前期研究的基础上,利用Mapmaker软件构建含有17个SSR或SNP分子标记的家蚕性染色体的遗传连锁图,并对茧丝量、全茧量、茧层量、蛹体质量、茧丝长等性状进行数量性状位点(QTL)扫描,获得与上述5项茧丝相关的QTL位点,其LOD值分别为11.175、6.196、11.036、5.156和8.717。研究结果为家蚕茧丝相关QTL位点的精细定位与克隆奠定了基础。     

猪细胞周期蛋白依赖性激酶2多克隆抗体的制备与鉴定

为研究猪细胞周期蛋白依赖性激酶2(pCDK2)的生物学功能,本试验构建重组原核表达载体pET28a-pCdk2,转化大肠杆菌BL21 (DE3)受体菌,用IPTG诱导重组蛋白(rpCDK2)表达并进行SDS-PAGE和Western blotting鉴定,蛋白经纯化及与弗氏佐剂乳化后免疫家兔制备多克隆抗体。分别用Western blotting和免疫过氧化物酶单层细胞染色法(IPMA)检测抗体的免疫活性。结果显示,成功表达了rpCDK2蛋白,该蛋白以可溶性和包涵体两种形式存在,可溶性rpCDK2蛋白分子质量约为38 ku,包涵体rpCDK2蛋白在38~43 ku间有3种不同分子质量形式;IPMA检测结果显示,所制备的pCDK2蛋白多克隆抗体与猪肾细胞(PK-15)和猪睾丸细胞(ST)免疫染色呈特异性反应,且Western blotting分析显示,多克隆抗体与这两种细胞的总蛋白反应出现4条特异性条带(分子质量在34~50 ku之间),可能跟pCDK2的多种磷酸化形式有关。本试验利用原核表达系统成功制备了rpCDK2蛋白,并制备了免疫活性和特异性良好的pCDK2蛋白多克隆抗体,为该蛋白生物学功能及相关疾病研究提供了基础材料。     

拜城油鸡肌肉生长抑制素基因多态性与生产性能的相关性研究

试验旨在研究肌肉生长抑制素（myostatin,MSTN）基因在拜城油鸡中的多态性及其与生产性能的关系,探寻可用于拜城油鸡选育的分子遗传标记。选取96只6周龄的拜城油鸡公鸡,随机分为3组,每组32只,分别在12、18和24周龄时对其生产性能指标进行测定,同时采用PCR-RFLP方法检测MSTN基因的多态性,分析MSTN基因多态性与拜城油鸡生产性能的关系。结果显示,在拜城油鸡公鸡中MSTN基因存在多态性,检测到3种基因型:AA、GA、GG,GA为优势基因型,等位基因A为优势等位基因,不符合哈代－温伯格平衡定律（P<0.05）。在12周龄时,AA基因型个体的体重、屠体重、半净膛重、全净膛重、胸肌重和腿肌重均显著高于GA基因型个体（P<0.05）;在18周龄时,GA基因型个体的体重、胸肌重和腿肌重均显著高于GG基因型个体（P<0.05）;在24周龄时,AA基因型个体的体重、屠体重和半净膛重均极显著高于GG基因型个体（P<0.01）,全净膛重和腿肌重显著高于GG基因型个体（P<0.05）,GA基因型个体的体重、屠体重、半净膛重和腿肌重均显著高于GG基因型个体（P<0.05）,其余指标在不同周龄不同基因型个体间差异不显著（P>0.05）。MSTN基因多态性与拜城油鸡部分生产性能指标密切相关,推测该基因可以作为拜城油鸡选育的分子遗传标记之一。     

Preparation and Identification of Polyclonal Antibodies against Porcine Cyclin Dependent Kinase 2

In order to research the biofunction of porcine cyclin dependent kinase 2 (pCDK2), this study prepared polyclonal antibodies against pCDK2.The recombinant prokaryotic expression plasmid pET28a-pCdk2 was constructed and transformed into BL21 (DE3), IPTG was used to induce the expression of recombinant pCDK2 (rpCDK2) which was then analyzed by SDS-PAGE and Western blotting.The expressed proteins were purified and emulsified with freund's adjuvant, the mixture was used to immunize the rabbits to prepare polyclonal antibodies against pCDK2.The immunocompetence of the antibody was identified by immunoperoxidase monolayer assay (IPMA), and the specificity was confirmed by Western blotting.The results showed that rpCDK2 was successfully expressed by prokaryotic expression system, and the expression products showed two forms:Solubility and inclusion body(IB), the molecular weight of the solute rpCDK2 was about 38 ku, however three different molecular weight forms (from 38 to 43 ku) of IB were observed.IPMA results showed that polyclonal antibodies against pCDK2 protein showed perfect activity which could recognize pCDK2 expressed in PK-15 cells and ST cells specifically.Western blotting analysis showed that four bands with different molecular weight forms (from 34 to 50 ku) were observed when the polyclonal antibodies against pCDK2 protein reacted with the total protein extracted from PK-15 and ST cells.In conclusion, the rpCDK2 protein was successfully expressed by prokaryotic expression system, the prepared rabbit polyclonal antibodies against pCDK2 protein showed wonderful activity and specificity, and the study provided basic material for the research of protein biofunction and related diseases.     

生长抑素基因第1外显子多态性与湘西黄牛体尺性状的关联分析

为探讨湘西黄牛分子遗传特征和寻找生长性状相关的分子标记,本试验采用PCR-SSCP方法检测湘西黄牛生长抑素(somatostatin,SST)基因第1外显子126 bp处g.934G>A位点的多态性,并进行了多态性与生长性状的关联分析。结果表明,湘西黄牛在g.934G>A位点有G和A两个等位基因,G等位基因占优势,检测到GG、AG和AA 3种基因型,呈中度多态,达到Hardy-Weinberg平衡状态(P>0.05)。湘西黄牛GG基因型个体的体高和体长显著大于AA基因型个体(P<0.05);GG和AG基因型个体的胸围和体重极显著大于AA基因型个体(P<0.01)。G等位基因对湘西黄牛的体高、体长、胸围和体重4个性状均为正效应。本试验结果提示,SST基因g.934G>A位点可能为湘西黄牛生长性状的分子遗传标记位点。     

Study on the Association Relationship Between the Polymorphism of MSTN Gene and Production Performance in Baicheng Fatty Chicken

In this study, the single nucleotide polymorphism(SNP) of MSTN gene and its correlation with the production performance was tested, and explored the molecular genetic marker of breeding in Baicheng fatty chicken. 96 Baicheng fatty chicken roosters were selected randomly and divided into 3 groups, there were 32 chicken in each group. The indexes of production performance were measured in 12, 18 and 24 weeks old and the SNP of MSTN gene was detected by PCR-RFLP method, and analyzed the relationship between gene polymorphism and production performance indexes.The results showed that 3 genotypes of AA,GA and GG were found in Baicheng fatty chicken, GA was the dominant genotype, and allele A was the dominant allele, the allele frequency was not in the Hardy-Weinberg equilibrium (P<0.05). At 12 weeks old,AA genotype was significantly higher than GA genotype in body weight, carcass weight,semi-eviscerated weight, eviscerated weight, breast muscle weight and leg muscle weight (P<0.05). At 18 weeks old,GA genotype was significantly higher than GG genotype in body weight, breast muscle weight and leg muscle weight (P<0.05). At 24 weeks old,AA genotype was extremely significantly higher in body weight, carcass weight and semi-eviscerated weight than GG genotype (P<0.01),and AA genotype was significantly higher in eviscerated weight and leg muscle weight than GG genotype (P<0.05). GA genotype was significantly higher in body weight, carcass weight,semi-eviscerated weight and leg muscle weight than GG genotype (P<0.05), there were no significant difference in the other indexes among different genotypes at different ages (P>0.05). MSTN gene polymorphism was closely related to the production performance indexes of Baicheng fatty chicken, it was speculated this gene could be used as one of the molecular genetic markers for the breeding of Baicheng fatty chicken.     

Molecular cloning of porcine parvovirus DNA for the purpose of obtaining viral antigen synthesis in bacteria

An expression of porcine parvovirus 1.05 kb DNA fragment was obtained in Escherichia coli under the control both of Pr-lambda and lac-promoters. The product of expression under Pr-control was demonstrated to show PPV-specific antigenic properties. Its electrophoretic mobility corresponded to a molecular weight of approximately 45 KD.     

蚕丝脱胶方法的比较分析

对高温高压水、尿素溶液和碳酸钠溶液煮沸的蚕丝脱胶方法作了比较研究。结果表明 ,蚕丝在高温高压条件下丝胶蛋白易于溶解 ,脱胶率达 80 %以上 ,获得的丝胶分子量大 (10～ 2 0 0kD) ;在碱性的碳酸钠溶液中煮沸脱胶 ,丝胶蛋白易于降解或水解 ,其回收的丝胶分子量 2 0kD以下。蚕丝在高温高压水或高温高压尿素溶液中的脱胶率都随着处理温度和压力的增大而提高 ,而回收的丝胶蛋白分子量随着处理温度和压力的增大而下降。高温高压水蚕丝脱胶法是一种高效率、低成本、无污染的脱胶方法 ,特别适用于绢纺厂、丝棉厂等蚕丝的脱胶与加工以及纺织厂生丝的精练等。     

副猪嗜血杆菌外膜蛋白TbpB基因的克隆和表达

为了克隆和表达副猪嗜血杆菌(Haemophilus parasuis,HPS)外膜蛋白TbpB基因,试验采用基因工程的方法对已发布的HPS外膜蛋白P5序列进行相关序列分析,设计并合成引物,以HPS血清5型基因组为模板,通过PCR扩增HPS外膜蛋白P5编码基因,获得长为1 116 bp的预期基因片段。该基因编码372个氨基酸的蛋白质,预测分子质量约为41 ku,将该基因片段定向克隆至表达载体pGE X-6p-1中。结果表明:诱导表达后分子质量约为67 ku,与副猪嗜血杆菌阳性血清发生了特异性反应。说明该蛋白与抗体发生了反应,有一定免疫原性。     

Free-radical scavenging properties of low molecular weight peptide（s） isolated from S1 cultivar of mulberry leaves and their impact on Bombyx mori （L.） （Bombycidae）

The mulberry leaves have been considered as a sole food source for silkworm, Bombyx mori （L.）. In present work an attempt was made to investigate the role of low molecular weight peptide（s） isolated from mulberry leaves on silkworm rearing. Also we have tried to find out the role of free-radical scavenging activities of isolated peptide（s） on silkworm growth. Larval growth rate was found effective under the influence of peptide（s）. Consumption rate of larvae after peptide（s） treatment on mulberry leaves was significantly enhanced over control. High antioxidant activity was found in Low molecular weight peptide（s） which have an effect on silkworm.     

Purification of carbonic anhydrase isozyme VI (CA-VI) from swine saliva.

Salivary or secreted carbonic anhydrase (CA), which constitutes a new class of CA, designated CA-VI, was isolated. Swine CA-VI purified from swine saliva by inhibitor-affinity chromatography and ion exchange chromatography had a specific activity of 5,468 units/mg. The molecular weight was 250,000, as determined by gel filtration under non-denaturing conditions, and the subunit molecular weight was found to be 37,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis, indicating that swine CA-VI consists of 7 subunits. The treatment of the enzyme with endo-N-acetylglucosaminidase F reduced its subunit molecular weight from 37,000 to 35,000 and 32,000. We raised a rabbit antibody against purfied swine CA-VI. Double immunodiffusion showed that anti-swine CA-VI serum reacted with swine CA-VI and swine saliva, but not with hemolysate (containing CA-I and CA-Il) or muscle extracts (containing CA-III). The concentration of CA-VI in swine saliva, measured using single radial immunodiffusion, was 0.027 +/- 0.017 mg/mg total protein.     

基于全基因组差异甲基化分析鉴别影响苏姜猪体重的候选基因

本研究旨在分析不同体重苏姜猪的全基因组DNA甲基化差异，以期筛选出影响苏姜猪体重的差异甲基化基因（differentially methylated genes，DMGs）。利用全基因组重亚硫酸盐测序（whole genome bisulfite sequencing，WGBS）技术分析了3头180日龄高体重和3头180日龄低体重苏姜猪的全基因组DNA的甲基化程度、差异甲基化区域（differentially methylated regions，DMRs）和DMGs，对DMGs进行GO和KEGG分析，鉴别影响苏姜猪体重的候选基因。结果显示，苏姜猪全基因组范围内胞嘧啶（C）的平均甲基化率为4.1%，胞嘧啶（C）甲基化平均98.41%发生在CG序列上，CG序列环境下外显子、内含子和3'UTR的甲基化水平高于启动子和5'UTR。本研究共检测出1 657个DMRs和575个DMGs，8号染色体上DMRs分布最多，88.89%的DMRs的长度在500 bp以内，62.78%的DMRs分布在远端基因间区，98个DMGs显著富集于TOR信号的负调控、碳水化合物衍生物分解代谢过程、脂肪细胞因子信号通路、FoxO信号通路等53个GO条目和29个信号通路，鉴别到5个与苏姜猪体重相关的候选基因：瘦素受体（leptin receptor，LEPR）基因、肿瘤坏死因子受体相关因子6（tumor necrosis factor receptor associated factor 6，TRAF6）基因、生肌因子6（myogenic factor 6，MYF6）基因、钙依赖性分泌激活因子2（calcium dependent secretion activator 2，CADPS2）基因和表皮生长因子（epidermal growth factor，EGF）基因。本研究利用WGBS绘制了高、低体重组苏姜猪的全基因组DNA甲基化图谱，为深入研究苏姜猪体重差异的分子机制奠定了基础。     

两个呼伦贝尔羊品系不同部位脂肪细胞形态及脂肪代谢相关基因表达差异分析

试验旨在探讨呼伦贝尔羊巴尔虎品系（半椭圆状尾）和短尾品系（小桃状尾）脂肪沉积差异的分子机制。随机选择处于相同饲养管理条件下5月龄呼伦贝尔母羊21只（其中巴尔虎品系11只、短尾品系10只）,测量其体尺、尾型和胴体重指标。组织切片观察8个部位脂肪细胞的形态,测定脂肪组织甘油三酯（TG）含量,并进一步用实时荧光定量PCR检测脂肪代谢相关基因在不同脂肪组织中的表达差异。结果显示,同月龄两品系羊胴体重、体尺及尾型指标差异显著或极显著（P<0.05;P<0.01）。虽然两品系羊同一部位的脂肪细胞形态基本一致,但巴尔虎品系尾部脂肪细胞面积和体积均大于短尾品系（P<0.01）,并且皮下、网膜和尾部脂肪组织中的TG含量在两品系羊间差异显著或极显著（P<0.05;P<0.01）。ATGL、PPARγ、C/EBPα和SREBP 4个脂代谢相关基因在巴尔虎品系个体中的mRNA水平均显著或极显著高于短尾品系（P<0.05;P<0.01）;巴尔虎品系中ATGL和SREBP基因的表达与TG含量分别呈显著负相关和正相关（r=-0.965、0.972）。综上所述,两个呼伦贝尔羊品系在生长和脂肪代谢等方面存在较大差异。本研究结果可为进一步深入解析绵羊脂尾形成的分子机制提供理论依据。     

Vaccination of Lewis rats against Mycoplasma arthritidis-induced arthritis.

The nature of Mycoplasma arthritidis antigens responsible for eliciting protective immunity in rats was studied by inoculation of rats with mycoplasmal components that had been subjected to a variety of physical and chemical treatments. All inocula tested induced good protection against development of clinical illness, as assessed by changes in body weight and appearance of joint swelling and/or temporary hind limb paralysis. Although all preparations stimulated development in inoculated rats of high titer of antimycoplasmal antibodies measured by ELISA, the complement-fixation antibody response was poor and, in some cases, lacking altogether. This indicated that completion-fixation antibodies may not be involved in protecting rats against M arthritidis-induced illness. Protective antigens were stable to heat (100 C for 10 minutes), formalin, and denaturation by sodium dodecyl sulfate (SDS). Inoculation with membrane and soluble cytoplasmic fractions was protective, as was inoculation with 5 M arthritidis fractions separated according to molecular weight by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). For this latter experiment, rat antisera obtained after vaccination, but prior to challenge exposure, were tested by immunoblot analysis against electrophoretically separated M arthritidis membrane proteins. Interestingly, all antisera from these rats recognized antigens migrating far outside the molecular weight range of the cell fractions with which rats were inoculated. This indicated either that the protective antigens may be composed of numerous antigenically related subunits that separated by SDS-PAGE into a variety of molecular weight ranges or that a few major antigens may exist in several forms or phases within a given population of M arthritidis.     

草地早熟禾干旱胁迫转录组差异性分析

干旱是影响草地早熟禾生产力的主要因素之一。在没有参考基因组的情况下, 为了揭示草地早熟禾在干旱处理下基因表达谱的变化, 本文采用了高通量Illumina Hiseq测序平台对草地早熟禾的对照组(CK)与干旱处理组(D)进行转录组测序, 并对测序数据进行了分析研究, 进一步探究了草地早熟禾干旱应答的分子机制。结果表明, 在干旱处理下共检测到24465个差异表达的基因, 筛选后获得4143个上调基因和4415个下调基因, 共占差异表达基因总数的34.98%。经富集分析后得, 与蛋白激酶、蛋白磷酸酶、碳代谢以及ABA等相关的基因可以作为研究草地早熟禾干旱响应机制的主要研究对象。qRT-PCR分析表明, 随机选出的8个差异性表达基因的表达趋势与高通量测序结果相一致。此外, 还候选了吲哚-3-甘油磷酸合成酶、蛋白磷酸酶、已糖激酶、钙结合蛋白、叶绿素a/b结合蛋白等基因作为与草地早熟禾干旱胁迫相关的应答候选基因, 为揭示草地早熟禾耐旱分子机制奠定了基础。