芒属(Miscanthus)植物种质资源研究进展

芒属植物属禾本科多年生高大草类,多分布于热带非洲至亚洲东南部。近年来在欧美国家受到广泛的关注,被认为是一种开发潜力巨大的生物质能源。本文查阅近年国内外相关文献,对芒属植物的生境、分布、遗传多样性、光合特性、抗性生理生化、繁殖学、饲草利用以及作为能源植物的研究等方面做了综述,并展望了其研究前景,旨在推动芒属种质资源的研究。     

中国10个地方鸡种卵壳超微结构研究及聚类分析

对中国 10个地方鸡种卵壳外表面、内表面、横断面和壳膜外表面、内表面的超微结构在扫描电子显微镜下进行了比较研究 ,从而看出鸡种间卵壳结构具有明显差异 ,中国地方鸡种具有遗传多样性。根据遗传距离较近的品种间卵壳的超微结构相似的理论 ,对 10个鸡种的形态结构进行了赋值 ,通过数值分类法进行了遗传相似度的计算和聚类分析 ,从而得出遗传距离最近的是白耳鸡和狼山鸡。     

β-内酰胺酶抑制剂与β-内酰胺类抗生素联用在兽医学上的应用

20世纪40年代,第一个β-内酰胺类抗生素青霉素的研制和应用,开创了抗生素治疗细菌性疾病的光辉时代。但细菌的耐药性也因抗生素的广泛应用而变得日益普遍,细菌对β-内酰胺类抗生素最主要的耐药机制是产生β-内酰胺酶,破坏β-内酰胺环使抗生素失活。β-内酰胺酶抑制剂的研制应用,恢复了β-内酰胺类抗生素的有效性,使β-内酰胺类抗生素得以继续发挥其在临床上强大的治疗作用。本文主要综述了β-内酰抑制剂的作用机制及其与β-内酰胺类抗生素联用的抗菌活性,以及在兽医临床上的应用概况。为有效地应用β-内酰胺类抗生素控制耐药菌感染提供参考。     

南阳牛IGF2基因第2外显子多态性及其与生长发育相关性研究

以126头纯种南阳黄牛为研究材料，利用PCR-RFLPs技术对胰岛素样生长因子2（IGF2）第2外显子的多态性及其与生长发育的相关性进行了分析。结果表明：南阳牛在该位点的遗传多态性丰富。检测到2种等位基因A和B，频率分别为0．6865和0．3135，A等位基因在群体中是优势等位基因；BB型个体的6、12、18、24月龄体斜长和胸围，12、18和24月龄的坐骨端宽，初生、6月龄和24月龄体重等体征性状显著地优于AA型；6月龄体斜长、12月龄的胸围、18月龄和24月龄坐骨端宽也显著优于杂合型。初步推断JGF2基因是非常有价值的辅助选择标记，可为南阳牛肉用型方向选择提供理论依据。     

肉牛对不同物理性状的玉米秸饲料利用效果的研究

为研究肉牛对不同玉米秸杆产品的利用情况,选18月龄西门塔尔牛与当地黄牛的F136头,分别用铡碎、揉碎、揉碎压捆、制粒、压块和挤压成棒状的六种玉米秸秆饲料进行了肉牛饲养试验和消化试验.结果秸秆采食量以后三种加工处理的秸秆为最高,铡碎为最低,揉碎和揉碎压捆居中;日粮表现消化率以秸秆颗粒型日粮最低,其他几种秸秆型日粮差异不大;肉牛增重以应用秸秆饲料块和秸秆饲料棒的肉牛增重效果最好,铡碎秸秆最差,揉碎和揉碎压捆居中.除铡碎型外,其他几种玉米秸杆饲料用于育肥牛均可取得较好的增重效果.     

柔嫩艾美耳球虫在鸡胚盲肠上皮细胞中体外培养营养条件的研究

探讨E.tenella在鸡胚盲肠上皮细胞体外培养的营养条件,观察其发育过程。用鸡胚盲肠上皮细胞体外培养E.tenella,对子孢子接种基础培养基、营养物质含量及血清浓度进行了优选,并对优化营养条件下E.tenella的发育过程进行了观察。MEM199培养基中24、48、72h的虫体感染率显著(P0.05)或极显著(P0.01)高于DMEM培养基;MEM199培养基中叶酸、VB6、VB1的含量为6mg·L-1时,24、48、72h的虫体感染率显著(P0.05)高于其他组,分别为25.33%、12.67%和12.33%;MEM199培养基中葡萄糖含量为3000mg·L-1,胰岛素含量为0.40mg·L-1时,有较多的成熟裂殖体形成;接种子孢子后于4、48、96h换液,接种时和4、48h血清浓度为2.5%,96h为1%,有利于子孢子的后期发育;优化营养条件下,细胞接种子孢子后4、24、48、72、96、120h的细胞虫体感染率分别为42%、28%、20%、15%、13.67%、13.67%,且E.tenella可在鸡胚盲肠上皮细胞中完成内生发育过程,并形成卵囊。结果表明,获得了能使E.tenella在鸡胚盲肠上皮细胞完成整个内生发育的体外培养营养条件。     

Expression and Bioinformatic Analysis of ADIPOQ Gene in Hanper Sheep

The aim of this study was to investigate the expression and biological characteristics of adiponectin (ADIPOQ) gene in longissimus dorsi muscle of Hanper sheep at different months of age.The ADIPOQ gene mRNA expression was detected in longissimus dorsi muscle of Hanper sheep at 3 different growth periods (1,7 and 13 months old) by Real-time quantitative PCR.The bioinformatics method was used to analyze the nucleotide and amino acid sequences of ADIPOQ gene,protein characteristics and network interaction protein.The results showed that ADIPOQ gene was expressed in longissimus dorsi muscle of Hanper sheep,which showed an increasing trend with the growth of the months age without significant difference (P>0.05).There was higher homology of ADIPOQ gene with Capra hircus (98.60%,99.00%) and Bos taurus (98.60%,87.00%) in nucleotide and amino acid sequences.The results of physical and chemical properties analysis showed that the molecular formula of ADIPOQ protein was C₁₁₇₂H₁₇₇₆N₃₁₄O₃₄₉S₅,the molecular mass was 26.00 ku,and the theoretical isoelectric point (pI) was 5.88,which suggested that the protein was acidic.The average value of ADIPOQ hydrophilic protein (GRAVY) was －0.403,which indicated that the protein was hydrophilic and didn’t belong to transmembrane protein.In addition,the signal peptide sequence was Met¹-Ala¹⁷,and the cleavage site was between Ala¹⁷ and Arg¹⁸.ADIPOQ existed collagen structure domain and C1Q conserved structure domain at position 45－101 and 101－237,respectively.The secondary structure mainly composed of random coil (66.95%).The construction of protein interaction network indicated that ADIPOQ might interact with ADIPOR1,ADIPOR2,CDH13 and LEP.The results provided a theoretical basis for further exploring the molecular biological functions of ADIPOQ gene in the process of muscle development in Hanper sheep.     

miR-127和miR-136在转基因克隆绵羊胎盘中的表达分析及其靶基因的鉴定

克隆动物胎盘发育缺陷是造成动物克隆效率低下的一个重要原因。目前认为克隆胎盘发育异常通常是由于一些基因表达的异常所致,与表观遗传修饰有关。microRNA是一种重要的表观遗传修饰方式,对动物胚胎发育和胎盘的形成有着重要的调控作用。为研究miR-127和miR-136在克隆动物胎盘中的表达情况及其与克隆动物发育缺陷的关系,本实验运用荧光定量PCR分析了死亡克隆绵羊胎盘和同期普通绵羊胎盘组织中miR-127和miR-136的相对表达量,并鉴定了miR-127和miR-136的靶基因及靶基因在胎盘中的表达情况。结果显示,miR-127和miR-136在克隆绵羊胎盘中的表达量分别增加了3.1和2.8倍。EGFP荧光敲除实验证实,胎盘发育相关基因Rtl1是miR-127和miR-136的靶基因,同时定量PCR分析发现Rtl1基因在克隆绵羊胎盘中的表达量降低了3/5。结果说明,miR-127和miR-136在克隆胎盘中的异常表达可导致Rtl1基因的低表达,这很可能是导致克隆动物死亡的一个重要原因。     

Molecular cloning,chromosomal localization and expression pattern of porcine ADP‐ribosylation factor(Arf) gene family

Adenosine diphosphate‐ribosylation factors (Arfs) are a family of guanosine triphosphate‐binding proteins involved in fundamental biological processes including secretion, endocytosis, phagocytosis, cytokinesis, cell adhesion and tumor cell invasion. We report here the molecular cloning, chromosome localization and expression analysis of porcine Arf1–6, of which Arf1–3 (Class I) have >93% similarity to each other and encode nearly similar proteins with 181 amino acids in length. Arf4 and Arf5 (Class II) are 78–81% homologous to Class I Arfs and both encode a protein of 180 amino acids, Arf6 (Class III) shows 64–68% homology to the other Arfs and encodes 175 amino acids. With radiation hybrid mapping, porcine Arf1–6 are assigned to chromosomes 14q21‐q22, 12p14, 5p12‐q11, 13q21.1, 18q24, 1q21‐q27, respectively. Moreover, real‐time quantitative RT‐PCR assays show that porcine Arf1‐6 are ubiquitous in all tissues examined, with the highest levels in the kidney and stomach and the lowest in muscle and the heart. This is the first report of molecular characterization of the Arf gene family in pigs.