猪HSD11B1和MyoG基因多态性与妊娠期长短的关系

选择HSD11B1和MyoG2个基因作为影响妊娠期长短的候选基因。在7个中外猪群体中采用PCR-RFLP技术研究了HSD11B1和MyoG2个基因多态性与妊娠期长短的关系。HSD11B1基因的PCR-Bsh1236Ⅰ-RFLP分析结果表明：清平猪、新清平猪母系、大白猪、长白猪、杜洛克猪、中国瘦肉猪新品系DIV1和DIV2系猪群中A等位基因的频率分别为0.538、0.752、0.522、0.941、1.000、0.889和0.594;除DIV2外,HSD11B1不同基因型与妊娠期长短无显著关系（P〉0.05）。MyoG基因的PCR-MspⅠ-RFLP分析结果表明：清平猪、新清平猪母系、大白猪、长白猪、杜洛克猪、中国瘦肉猪新品系DIV1和DIV2系猪群中M等位基因的频率分别为1.000、0.534、0.370、0.115、0.094、0.382和0.243;清平猪中只存在MM基因型,其他群体中3种基因型皆有分布;新清平猪母系MM比NN基因型母猪妊娠期要短,且在经产长白猪中差异极显著（P〈0.01）。     

伪狂犬病病毒在NF-κB家族p65基因敲除细胞系的复制规律研究

试验旨在研究伪狂犬病病毒（PRV）在NF-κB家族p65基因敲除细胞系中的复制规律。利用慢病毒介导的CRISPR/Cas9基因定点修饰技术构建猪肺泡巨噬细胞（3D4/21）p65基因稳定敲除细胞系。通过构建p65-sgRNA重组质粒,转染至HEK293T/17细胞,收取慢病毒,感染3D4/21细胞后利用嘌呤霉素筛选获得多克隆细胞系,T7核酸酶检测敲除效率,再通过有限稀释法获得3D4/21-p65^-/-的稳定细胞系。CCK-8试剂盒检测3D4/21细胞中敲除p65基因后对细胞增殖的影响;流式细胞术检测PRV-GFP感染3D4/21及3D4/21-p65^-/-细胞后病毒增殖的差异;实时定量PCR检测PRV感染3D4/21及3D4/21-p65^-/-细胞后PRV gB、TK基因mRNA表达水平及PRV感染细胞诱导的IL-1β和IL-6基因mRNA水平表达的变化;Western blotting检测PRV-QXX感染3D4/21及3D4/21-p65^-/-细胞后PRV gB、gE蛋白的表达;滴度测定检测PRV-QXX感染3D4/21及3D4/21-p65^-/-细胞后子代病毒滴度。结果表明,sgRNA2和sgRNA3的基因编辑效率较高,对其进行克隆化培养进而获得敲除p65基因的稳定表达细胞系;CCK-8试剂盒检测细胞活力表明,p65基因敲除对细胞活力无影响;流式细胞仪检测表明,同一时间点PRV-GFP在3D4/21-p65^-/-中的增殖显著高于对照细胞;实时荧光定量PCR表明在3D4/21细胞中敲除p65基因促进了PRV gB、TK基因的mRNA表达水平,而抑制了IL-1β、IL-6基因的mRNA表达;Western blotting结果表明,在3D4/21细胞中敲除p65基因促进了PRV gB、gE蛋白的表达;滴度测定结果表明,同一时间点PRV-QXX在3D4/21-p65^-/-细胞中子代病毒的复制显著高于对照细胞。以上结果均表明,p65基因敲除可促进PRV在3D4/21细胞中复制。     

表达大肠杆菌K88ac-ST1-LTB融合蛋白工程菌株的免疫原性研究

已构建的能表达大肠杆菌K88ac-ST1-LTB融合蛋白的工程菌株BL21（DE3）（pXKST3LT5)及其表达产物经动物试验证实没有毒性反应。用从IPTG诱导的工程菌中提取的包涵体或经甲醛灭活的工程菌制成抗原，免疫小鼠，结果免疫小鼠至少能抵抗2MLD的大肠杆菌强毒株C83902（K88ac,ST^ ,L^ )的攻击，用提取的包涵体免疫家兔后，采集的血清能够中和天然ST1的毒性，这表明构建的工程菌株BL21（DE3）（pXKST3LT5)可以作为预防幼畜大肠杆菌性腹泻基因工程菌苗的候选株。     

Serum cobalamin concentrations in healthy cats and cats with non-alimentary tract illness in Australia

Objective   To determine a reference range for serum cobalamin concentration in healthy cats in Australia using a chemiluminescent enzyme immunoassay and to prospectively investigate the prevalence of hypocobalaminaemia in cats with non-alimentary tract disease.
Design   Prospective study measuring serum cobalamin concentrations in clinically healthy cats and cats with non-alimentary tract illness.
Procedure   Blood was collected from 50 clinically healthy cats that were owned by staff and associates of Veterinary Specialist Services or were owned animals presented to Creek Road Cat Clinic for routine vaccination. Blood was collected from 47 cats with non-alimentary tract illness presented at either clinic. Serum cobalamin concentration was determined for each group using a chemiluminescent enzyme immunoassay.
Results   A reference range for Australian cats calculated using the central 95th percentile in the 50 clinically healthy cats was 345 to 3668 pg/mL. Median serum cobalamin concentration in 47 cats with non-alimentary tract illness (1186 pg/mL; range 117–3480) was not significantly different to the median serum cobalamin of the 50 healthy cats (1213 pg/mL, range 311–3688). Using the calculated reference range one sick cat with non-alimentary tract illness had a markedly low serum cobalamin concentration.
Conclusion   Although hypocobalaminaemia is uncommon in sick cats with non-alimentary tract illness in Australia, its occurrence in this study warrants further investigation.     

抗原表位研究方法进展

抗原表位是抗原分子中的主要功能单位,能有效刺激机体的细胞免疫和体液免疫。随着免疫学和生物信息学技术的不断发展,用于研究T细胞表位和B细胞表位的方法得到了很大的提高。论文中概述了近几年用于研究T细胞表位的预测方法和鉴定方法,以及在B细胞表位研究中所用的表位肽扫描技术、蛋白质切割法、噬菌体展示技术、X-衍射与核磁共振、表位预测方法等技术,并对每种研究方法进行了比较,为从事抗原表位研究的人员提供参考,从而更有利于表位肽疫苗的研制和诊断方法的建立。     

猕猴血清B病毒抗体3种检测方法的比较

为了解猕猴B病毒3种检测方法的检测效果,用3种方法对猕猴血清B病毒抗体分别进行检测并比较。结果表明,幼年组HSV-1EIA法检测结果与BV ELISA法比较差异显著(P<0.05),HSV-1EIA法与BV EIA法符合率96.6%,HSV-1EIA法与BV ELISA法符合率95.3%,BV EIA法与BVELISA法符合率98.7%。表明3种抗体检测方法检测结果符合率较高,均可以做为初筛检测,但BVELISA法在幼年猕猴血清B病毒抗体检测上敏感性最好。     

Orf virus circulation in cattle in Turkey

Orf virus (ORFV) causes contagious skin disease that mainly affects sheep and goats with zoonotic potential. However, there is not enough information about the association between ORFV and occurrence of skin disease in cattle. The present study describes outbreaks of ORFV infection in cattle in different provinces that are located in the Aegean, Central Anatolian and Mediterranean regions of Turkey. During the months of June and August 2017, vesicular fluid and scab samples were collected from cattle which had proliferative skin lesions. First, presence of lumpy skin disease virus (LSDV) and bovine herpesvirus 2 (BoHV-2, known as the causative agent of pseudo-lumpy skin disease) were investigated by real time PCR and PCR, respectively. Then, samples tested for the presence of parapoxviruses by PCR using primers specific to major envelope protein gene (B2L). Parapoxvirus DNA was detected in investigated samples whereas LSDV and BoHV-2 DNA were not detected. The analysis of the B2L gene sequences revealed that cattle were infected with ORFV. The isolates in the present study shared 100% sequence identity at the nucleotide and amino acid level when compared with previously characterised Turkish field ORFV isolates from goats in 2016. Results of the study show unusual infection of cattle with ORFV, and suggest that ORFV jumps the host species barrier from goats to cattle.     

Brucellosis in Argentina

Brucellosis has been recognized in Argentina since the 19th century. Several studies demonstrated the presence of the disease in most of the domestic species. Actually, the estimate of prevalence is that between 10 and 13% of the farm animals are infected with bovine brucellosis with an individual rate of 4–5%. The annual economical losses have been estimated at US$ 60,000,000. The control of bovine brucellosis began in 1932 and successive resolutions have been issued since then. The current resolution indicates that B. abortus S19 is mandatory in female calves between 3 and 8 months of age. The vaccine strain B. abortus RB51 was provisionally approved but only for cattle older than 10 months of age. The brucellosis control program consists principally of test and slaughter. This methodology has been successful mainly in the dairy farms that have the incentive due to increased pricing because of obtaining a low prevalence of the disease. Brucellosis has been found in porcine, caprine, ovine and canine species. All Brucella species have been found in the country. Human brucellosis is an important disease and a national coordinated diagnostic net has been formed to better control the disease in man.     

2018年中国部分地区猪瘟病毒2.1d亚型新流行株的基因组特征分析

为了解中国猪瘟病毒（classical swine fever virus,CSFV）的分子流行病学及遗传变异情况,本研究应用RT-PCR方法对2018年采集自河南、河北、山东、黑龙江和辽宁5个省份的350份疑似CSFV感染的病料进行E2和NS5B基因扩增,并对PCR产物进行测序和序列分析。结果显示,350份样品中21份为CSFV阳性,共获得14株CSFV的E2基因序列和7株CSFV的部分NS5B基因序列。E2全基因、NS5B部分基因序列分析表明,21份阳性样品均属于近年来在中国流行的CSFV 2.1d亚型,且新发现的2.1d亚型CSFV与中国较早2.1d亚型CSFV毒株间同源性差异不大,新发现的2.1d亚型CSFV分离株在E2基因的6个氨基酸（R³¹、S³⁴、W¹⁸²、K²⁰⁵、K³⁰³、A³³¹）上具有相同的分子特征,E2蛋白中15个位点上的半胱氨酸均未发生变异。韩国2.1d亚型CSFV在E2蛋白上具有3个独特的氨基酸（N⁹⁷、K¹⁵⁹、R²⁰⁵）特征,并且发现了韩国毒株YC11WB可能作为2.1b和2.1d亚型CSFV过渡毒株的证据,流行于中国和韩国的2.1d亚型CSFV可能分别来自于本国早期2.1b亚型CSFV的衍化。本研究证实,2018年中国及周边国家CSFV较为活跃,且流行毒株依然以2.1d亚型为主,为中国科学防控CSFV提供了依据。     

细胞松弛素B浓度对小鼠卵母细胞去核效果的影响

目的　探讨细胞松弛素 B浓度对小鼠卵母细胞去核效果的影响。方法　常规超排 KM小鼠获卵母细胞 ,将有明显第一极体的卵母细胞放入含有 5× 10 - 3、1× 10 - 2 、2× 10 - 2 g/ L CB的成熟培养液中孵育 15 min,采用盲吸法去核 ,去核后的卵母细胞放入含 5× 10 - 3g/ L Hoechst33342的成熟培养液中染色 15 min,在荧光显微镜下检查去核的效率。结果　 CB组去核率可达 88.2 % ,而对照组去核成功率仅达 2 9.7% ,两者的去核效果统计学上有显著差异 ;同时 CB的浓度过高会影响去核的效果 ,使卵母细胞的破溃率升高。结论　 CB有利于去核 ,同时卵胞膜可以借助磷脂双层的游动性而很快得到修复 ;高浓度的 CB对卵胞膜作用过于强烈 ,细胞骨架严重破坏 ,磷脂双层结构的弹性和粘性减弱 ,修复能力降低 ,影响胚胎的构建。