Effect of dipeptide on intestinal peptide transporter 1 gene expression: An evaluation using primary cultured chicken intestinal epithelial cells

Peptide transporter 1 (PepT1) is a transporter responsible for absorbing dipeptide and tripeptide in enterocytes and is upregulated by dipeptide in mammals. It has not been certain whether intestinal PepT1 expression is responsive to dipeptides in chickens because of the lack of in vitro study using the cultured enterocytes. This study established a primary culture model of chicken intestinal epithelial cells (IECs) in two-dimensional monolayer culture using collagen gel by which the response of chicken PepT1 gene expression to dipeptide stimuli was evaluated. The cultured chicken IECs showed the epithelial-like morphology attached in a patch-manner and exhibited positive expression of cytokeratin and epithelial cadherin, specific marker proteins of epithelial cells. Moreover, the chicken IECs exhibited the gene expression of intestinal cell type-specific marker, villin1, mucin 2, and chromogranin A, suggesting that the cultured IECs were composed of enterocytes as well as goblet and enteroendocrine cells. PepT1 gene expression was significantly upregulated by synthetic dipeptide, glycyl-l-glutamine, in the cultured IECs. From the results, we herein suggested that dipeptide is a factor upregulating PepT1 gene expression in chicken IECs.     

绵羊BMP15基因B2突变可视化检测技术的建立

骨形态发生蛋白15（bone morphogenetic protein 15,BMP15）基因突变对绵羊排卵率、产仔数以及繁殖力有很大影响,本研究旨在建立快速可视化检测BMP15基因B2突变的技术。将改良的扩增阻滞突变系统（amplification refractory mutation system,ARMS）与核酸染料SYBR Green Ⅰ结合,针对BMP15基因B2突变设计ARMS特异性引物,使引物下游3'端的最后一个碱基为A,并在下游引物3'端的第3位碱基处设计额外的错配,以提高引物的特异性;经ARMS PCR扩增后,向产物中加入SYBR Green Ⅰ,通过肉眼观察PCR管内的颜色变化来检测BMP15基因的B2突变。经测序发现所采集的样本均为野生型,因此,利用重叠延伸PCR构建BMP15基因B2突变型模板,测序结果显示BMP15基因B2突变型模板构建成功。ARMS PCR结果显示,ARMS特异性引物能够只扩增突变型模板,而不会扩增野生型模板,且扩增效果良好。ARMS PCR扩增后加入SYBR Green Ⅰ发现已知野生型模板与阴性对照一致,呈SYBR Green Ⅰ原始颜色橙黄色,而已知突变型模板呈亮绿色,且色差明显,肉眼可辨。用建立的可视化检测BMP15基因B2突变的技术检测50个小尾寒羊基因组DNA （随机向其中20个样本中加入构建的BMP15基因B2突变型模板）,将可视化检测的突变型样本编号与混合样本时记录的编号对比,结果表明该技术能够准确检测绵羊BMP15基因的B2突变,且准确率高达100%。将构建的BMP15基因B2突变型的模板进行梯度稀释,对本试验可视化检测体系的灵敏度进行检测,发现ARMS可视化检测技术的灵敏度达到0.006 ng/μL。因此,本研究建立的技术能够可视化地检测绵羊BMP15基因B2突变,且准确率高,有望为高繁殖力绵羊的选育提供技术支持。     

绒山羊皮肤毛囊兴盛前期组织形态、chi-miR-107-3p与RHBDF2基因表达分析

为了探究chi-miR-107-3p和菱形家族蛋白2（rhomboid family member 2,RHBDF2）基因在不同品种（系）和光控增绒绒山羊兴盛前期（5~7月份）皮肤毛囊重建时的表达差异,本试验在7月份采集内蒙古阿拉善型绒山羊、敏盖绒山羊和光控增绒技术处理的阿尔巴斯型绒山羊体侧皮肤毛囊组织,采用组织切片技术对组织形态比较分析,实时荧光定量PCR法检测chi-miR-107-3p和RHBDF2基因的表达量。结果显示,在皮肤毛囊兴盛前期,阿拉善型绒山羊次级毛囊正处于重建阶段,敏盖绒山羊和阿尔巴斯型绒山羊（光控增绒）次级毛囊重建已基本完成;在阿拉善型绒山羊皮肤组织中chi-miR-107-3p表达量极显著高于敏盖绒山羊和阿尔巴斯型绒山羊（光控增绒）（P<0.01）,而RHBDF2基因表达量极显著低于其他两品种（系）（P<0.01）,且RHBDF2基因表达量在敏盖绒山羊皮肤组织中显著低于阿尔巴斯型绒山羊（P<0.05）。不同品种（系）和光控增绒绒山羊皮肤毛囊兴盛前期组织显微结构与chi-miR-107-3p、RHBDF2基因在皮肤组织中的表达差异分析结果相一致,次级毛囊重建初期chi-miR-107-3p表达量较高,而RHBDF2基因表达量极低,随着次级毛囊重建完成,chi-miR-107-3p表达量明显降低,RHBDF2基因表达量逐渐增高,且在不同品种（系）内蒙古绒山羊绒毛生长发育过程中的表达机制基本相同。因此,chi-miR-107-3p和RHBDF2基因是绒山羊皮肤毛囊生长发育的重要调控因子。     

猪戊型肝炎病毒ORF3蛋白影响HepG2细胞核黄素代谢的lncRNA-mRNA调控网络的鉴定

为初步鉴定并挖掘出猪戊型肝炎病毒(Hepatitis E virus,HEV)ORF3蛋白影响HepG2细胞核黄素代谢信号通路的lncRNA-mRNA调控网络,本试验通过构建腺病毒过表达载体,制备高滴度过表达腺病毒,介导猪 HEV-ORF3在HepG2细胞中实现过表达。Western blotting检测ORF3蛋白过表达成功后,运用lncRNA高通量组学测序,筛选出差异表达的lncRNA并进行靶向差异基因预测,对lncRNA靶向差异基因进行GO功能和KEGG通路富集分析,初步鉴定出与核黄素代谢信号通路相关的lncRNA-mRNA调控网络。Western blotting结果显示,在约为12 ku处出现目的条带,说明成功实现腺病毒介导猪HEV-ORF3在HepG2细胞中过表达。lncRNA高通量组学测序结果显示,共发现102个显著差异表达lncRNAs表达量上调,80个显著差异表达lncRNAs表达量下调。GO功能和KEGG通路富集分析显示,初步挖掘出lncRNA(MSTRG.13995.2)和lncRNA(MSTRG.1960.1)可能是与核黄素代谢信号通路相关的显著差异表达lncRNA,分别通过顺式调控其靶向基因APC-5和FLAD1来影响核黄素代谢信号通路。本试验初步鉴定出lncRNA(MSTRG.13995.2)-APC5和lncRNA(MSTRG.1960.1)-FLAD1可能是影响HepG2细胞核黄素代谢信号通路的lncRNA-mRNA调控网络。     

猪圆环病毒2型灭活疫苗中病毒抗原含量实时荧光定量PCR检测方法的建立

依据GenBank公布的猪圆环病毒2型Cap基因序列,在保守区域设计特异性引物和TaqMan探针,优化反应体系,建立评价猪圆环病毒2型灭活疫苗中病毒含量的实时荧光定量PCR检测方法,对方法的特异性、敏感性和重复性进行试验,并验证灭活剂用量和灭活时间对检测结果的影响。结果显示：该方法只对猪圆环病毒2型基因有特异性扩增,其他3种对照病毒基因的扩增结果均为阴性;检测灵敏度达到10^2.0 TCID₅₀/mL,比普通PCR方法高100倍;方法的重复性好,对同一样品进行10次检测,变异系数为2.28%;不同灭活剂用量和灭活时间对结果的影响较小,不会因各厂家使用的灭活剂用量和灭活时间不同,影响疫苗对比实验的公平性。该研究成功建立了一种评价猪圆环病毒2型灭活疫苗中病毒含量的实时荧光定量PCR检测方法,用于猪圆环病毒2型灭活疫苗样品中病毒抗原含量的定量,其结果可以反映不同猪圆环病毒2型灭活疫苗样品中抗原含量差异,为研究猪圆环病毒2型灭活疫苗病毒抗原含量评估方法提供了新的思路。     

2019—2020年新疆部分地区猪PCV2的抗体水平检测及分析

为了解2019—2020年新疆地区猪圆环病毒病2型（PCV2）抗体水平及其消长规律,本试验采用间接酶联免疫吸附试验（ELISA）方法对475份血清中PCV2免疫抗体水平进行检测和分析。结果显示,PCV2抗体平均阳性率为69.68%（331/475）,未达到国家规定标准（70%）。S/P的平均值为1.56。不同类别猪群抗体平均阳性率在42.50%~86.67%之间,有一定的差异。在调查的5个规模化养殖场中,仅有2个场PCV2免疫抗体阳性率达到国家标准。各场应根据抗体检测结果,进一步对现有的免疫程序进行调整和完整,确保各猪群健康。     

基于HYDRUS-2D的地下滴灌下水分运移数值模拟研究

利用HYDRUS-2D软件模拟了地下滴灌条件下滴头周围黏壤土的土壤水分动态,并与田间观测进行对比;通过分析不同滴头流量对试验地土壤湿润模式的影响,明确了最佳灌水技术参数。结果表明,HYDRUS-2D软件模拟结果与观测值一致,体积含水率均方根误差为1.2%~4.5%,湿润范围均方根误差变化范围为2.1~3.87cm。     

Preparation and Identification of Canine Parvovirus NY Strain VP2 Protein Polyclonal Antibody

This study was aimed to prepare canine parvovirus (CPV) VP2 protein polyclonal antibody.The recombinant expression vector pET28a-CPV-VP2 was constructed and transfromed into E.coli BL21 (DE3),the expression of recombinant proteins was induced by IPTG from which the fusion protein was identified by SDS-PAGE.The target protein was purified and emulsify with adjuvant,the prepared immunogen was inoculated into rabbit by subcutaneous injections to prepare of VP2 protein specific polyclonal antibody.The immuno-activity,titers,neutralization titers of the prepared polyclonal antibody were determined by immunoperoxidase monolayer assay (IPMA).The results showed that the expressed recombinant protein VP2 (rVP2) existed in the form of inclusion body with a molecular weight of 72 ku.The prepared polyclonal antibody titer was 1 600 dilution,the virus titer was 10⁷ TCID₅₀/mL,the neutralizing titer was 1∶2 884.The antibodies showed specific reaction with CPV.In conclusion,rVP2 specific polyclonal antibody showed wonderful immunocompetence,specificity and neutralizing activity,providing foundation for the development of genetic vaccine and clinical therapeutic method.