An Example of Yak Paternity Assignment by Microsatellite Genotyping

12 cattle microsatellite DNA markers were used for establishing the paternity of 4 Datong Yak calves.The results indicated that paternity can be assigned by use of exclusion method directely when the mother is clearly known and data of all likely sires were obtained. The more the alleles of a locus possessed, the more effectively the paternity can be assigned. Not only the microsatellite DNA marker is a promising tool in establishment of yak detail pedigrees, but also can provide us information of reproductive efficiency of the bull(s) based on the numbers of calves it produced in the herd, which will be useful in speeding up the processes of yak genetics improvement.     

Endometrial response to conceptus-derived estrogen and interleukin-1β at the time of implantation in pigs

The establishment of pregnancy is a complex process that requires a well-coordinated interaction between the implanting conceptus and the maternal uterus. In pigs, the conceptus undergoes dramatic morphological and functional changes at the time of implantation and introduces various factors, including estrogens and cytokines,interleukin-1β2(IL1 B2), interferon-γ(IFNG), and IFN-δ(IFND), into the uterine lumen. In response to ovarian steroid hormones and conceptus-derived factors, the uterine endometrium becomes receptive to the implanting conceptus by changing its expression of cell adhesion molecules, secretory activity, and immune response. Conceptus-derived estrogens act as a signal for maternal recognition of pregnancy by changing the direction of prostaglandin(PG) F2αfrom the uterine vasculature to the uterine lumen. Estrogens also induce the expression of many endometrial genes,including genes related to growth factors, the synthesis and transport of PGs, and immunity. IL1 B2, a pro-inflammatory cytokine, is produced by the elongating conceptus. The direct effect of IL1 B2 on endometrial function is not fully understood. IL1 B activates the expression of endometrial genes, including the genes involved in IL1 B signaling and PG synthesis and transport. In addition, estrogen or IL1 B stimulates endometrial expression of IFN signaling molecules,suggesting that estrogen and IL1 B act cooperatively in priming the endometrial function of conceptus-produced IFNG and IFND that, in turn, modulate endometrial immune response during early pregnancy. This review addresses information about maternal-conceptus interactions with respect to endometrial gene expression in response to conceptus-derived factors, focusing on the roles of estrogen and IL1 B during early pregnancy in pigs.     

雉鸡的繁殖规律与繁殖方法

1 性成熟期 　　雉鸡的性成熟较晚,而且具有明显的季节性.野生雉鸡在北方每年4月以后开始产蛋,产蛋主要集中在5～6月,到7月底结束.当年孵出的雏雉鸡,要等到第2年10月龄左右才能达性成熟.如6月孵出的雏雉,翌年4月即可交配产蛋.……     

柠檬酸对三黄土鸡早期生产性能的影响

用海大香特1号三黄土鸡雏鸡进行饲养试验，对添加0．3％、0．5％、0．7％柠檬酸饲养的试验组和不添加柠檬酸饲养的对照组进行体增重、采食量、料肉比等生产性能的比较，试验结果表明：添加0．3％柠檬酸试验组的三黄土鸡早期体增重，显著高于对照组，同时也高于添加0．5％、0．7％柠檬酸的试验组；添加0．3％柠檬酸试验组的料重比、成活率也优于其他试验组。     

鸭瘟病毒UL51基因在感染宿主细胞中的定位和转录特征

对鸭瘟病毒(DPV)UL51基因在感染宿主细胞内的定位和转录时相进行分析,为进一步研究该基因的特性和功能提供有用的试验数据和材料。构建pET32a-UL51原核表达载体,将其转化至E.coliBL21(DE3)中进行IPTG诱导表达后,用Ni2+-NTA琼脂糖凝胶柱层析法纯化该表达产物。以纯化的重组蛋白为抗原免疫兔子,制备兔抗UL51多克隆抗血清,通过间接免疫荧光和RT-PCR法检测该基因在DPV感染的鸭胚成纤维细胞(DEF)内的定位和转录情况。间接免疫荧光结果显示,最早可在感染后8h的胞浆中检测到特异性荧光点,24～36h有大量绿色荧光团块聚集于近核区域,之后随着细胞病变的增强,胞浆中的绿色荧光开始减弱,且在感染晚期的胞核中也出现了少量弥散的绿色荧光。RT-PCR结果显示,DPVU L51基因从感染后4h开始转录,其后转录量不断增大,从6～48h一直保持在较高水平,之后又降低。DPVU L51蛋白主要定位于感染的宿主细胞的胞浆中特别是近核区域,与其在α-疱疹病毒中的同源物的定位结果一致;并且与其他几种α-疱疹病毒的转录情况对比后,可认为该基因是一个晚期(γ类)基因。     

加强通风和喷雾降温对奶牛生产性能的影响

黑白花奶牛是耐寒怕热的家畜，适宜温度范围44～211℃，产奶最适宜温度10℃，当环境温度自21℃升高至35℃，产奶量将大幅下降，乳的组成亦发生变化。合肥地区属于亚热带季风气候，夏季温度高达35℃以上，极端最高温度达40℃，奶牛长时期处于这种环境中，高温引起热应激反应，散热困难，体温升高，采食量减少，增加散热的能量消耗和体蛋白质的分解，造成内分泌活动和酸碱平衡失调乃至死亡。为降低热应激对奶牛生产的影响，我场在夏季采用强制通风和喷雾的措施，可提高奶牛单产达20％的显著效果。1 材料与方法11 喷雾设备111 加压泵…     

枯草杆菌的淀粉酶基因在大肠杆菌中的表达

根据枯草杆菌(Bacillus subtilis)基因文库中的淀粉酶基因的碱基序列,设计引物。以枯草杆菌菌体DNA为模板,利用PCR扩增出分子量大约为2.3 kb的淀粉酶基因片段。借助于核酸内切酶和连接酶把该基因植入到pHMSXD1质粒中,构建pHMSXD2质粒载体。通过高压电击处理把载体植入到大肠杆菌(JM10)中并成功表达。该株大肠杆菌在酶基因表达后,其淀粉酶活力达到1.037 6 U/mL(LB培养液)和1.361 0 U/mL(矿物元素培养液),分别比原始的枯草杆菌的淀粉酶活力提高了46倍和286倍。     

A peptide of foot-and-mouth disease virus serotype Asia1 generating a neutralizing antibody response, and an immunostimulatory peptide

The epitopes of the capsid of foot-and-mouth disease virus (FMDV) play important roles in the construction of highly immunogenic subunit vaccines. However few epitopes have been found for FMDV serotype Asia1. In this study we screened for epitopes of the VP1 and VP2 proteins of FMDV serotype Asia1 isolate, YNBS/58. Fragments consisting of amino acids 133-163 of VP1 and amino acids 1-33 of VP2 contained epitopes, and both induced lymphoproliferation in guinea pigs. Only the VP1 fragment induced neutralizing antibodies but the VP2 peptide dramatically increased the neutralizing antibody response induced by the VP1 peptide.     

丁酸钠及其配伍在断奶仔猪中的应用效果

为研究丁酸钠及其配伍对断奶仔猪生长性能的影响,本试验选用(21±1)日龄断奶、(7.28±0.15)kg健康"杜×长×大"杂交仔猪150头,随机分为5个处理组,每个处理组3个重复(栏),每个重复10头仔猪,公母各半。试验日粮是在基础日粮基础上分别添加10%硫酸抗敌素预混剂600mg/kg(对照组)、0.1%丁酸钠(试验Ⅰ组)、0.2%丁酸钠(试验Ⅱ组)、0.1%丁酸钠+10%硫酸抗敌素预混剂200mg/kg(试验Ⅲ组)和0.1%丁酸钠+10%硫酸抗敌素预混剂400mg/kg(试验Ⅳ组)。试验期为14d。试验结果表明,在断奶仔猪日粮中添加丁酸钠及其与硫酸抗敌素配伍均显著降低断奶仔猪腹泻发生率(P<0.05),并有提高断奶仔猪的平均日增重和采食量、降低料重比的趋势(P<0.05)。且0.1%丁酸钠与10%硫酸抗敌素预混剂400mg/kg配伍使用对仔猪抗腹泻、促生长的效果最好。