产气荚膜梭菌α—β融合基因的构建

用PCR从含产气荚膜松菌β毒素基因的质粒pXETB2中扩增出β毒素基因，NcoⅠ和BamHⅠ双酶切该β毒素基因，回收0.93kb的β毒素基因片段，再用NcoⅠ和BamHⅠ双酶切含产气荚膜梭菌α毒素基因质粒pXETA1,与上述回收的β毒素基因片段连接，转化至受体菌BL21（DE3）中，经NcoⅠ，NotⅠ酶切反应鉴定和苷酸序列分析证实，获得的重组质粒pXCPAB1含有α－β融合基因，重组菌株BL21（CD3）（pXCPAB1)表达产物经ELISA检测和SDS－PAGE分析，表明重组菌株可以表达α－β融合蛋白。     

一步法实时定量RT-PCR检测小反刍兽疫病毒方法的建立

建立了检测小反刍兽疫病毒的快速、特异的基于Taqman的一步法实时定量RT-PCR方法。通过对GenBank已公布的小反刍兽疫病毒N基因序列进行序列比较分析,设计了一对特异性引物和一条Taqman探针。利用这对引物和探针对来自不同疫源地的小反刍兽疫病毒RNA样本进行检测,都获得了特异性扩增,但是,不与牛瘟病毒、海豚麻疹病毒等其他种的麻疹病毒属病毒发生交叉反应。本方法具有高度灵敏性,最低可检测到810拷贝的RNA模板。在模板浓度为8.1×102到8.1×108拷贝范围内,都呈现良好的线性关系,而且无论是组内和或组间重复的变异系数都很低。     

放牧对鸭茅能量积累及分配的影响

通过长期放牧试验，探讨了不同放牧强度下亚热带高山草地鸭茅种群能量积累规律及能量在不同构件之间的分配特征。在无放牧的对照草地及采食率分别为55％、65％、80％的放牧草地，鸭茅热值随放牧强度的增加而呈单峰曲线型变化，一定强度范围内的放牧干扰提高了鸭茅热值及能量的积累；根部能量的积累随放牧强度的提高而逐渐减少。在禁牧草地，鸭茅种群能量主要被低密度的大分蘖丛所分摊，随着放牧强度的提高，种群能量则逐渐均摊给高密度的小分蘖丛。     

Effects of road transportation on metabolic and immunological responses in Holstein heifers

This study examined the effects of road transportation on metabolic and immunological responses in dairy heifers. Twenty Holstein heifers in early pregnancy were divided into non‐transported (NT; n = 7) and transported (T; n = 13) groups. Blood was collected before transportation (BT), immediately after transportation for 100 km (T1) and 200 km (T2), and 24 h after transportation (AT). The T heifers had higher (P < 0.05) blood cortisol and non‐esterified fatty acid concentrations after T1 and T2 than did NT heifers. By contrast, the T heifers had lower (P < 0.05) serum triglyceride concentrations after T1 and T2 than had the NT heifers. The serum cortisol and triglyceride concentrations returned (P > 0.05) to the BT concentrations at 24 h AT in the T heifers. The granulocyte‐to‐lymphocyte ratio and the percentage of monocytes were higher (P < 0.05) after T2 in the T heifers than in the NT heifers, suggesting that transportation stress increased the numbers of innate immune cells. T heifers had higher (P < 0.01) plasma haptoglobin concentrations than NT heifers 24 h AT. In conclusion, transportation increased cortisol secretion and was correlated with increased metabolic responses and up‐regulation of peripheral innate immune cells in dairy heifers.     

松辽黑猪胰岛素样生长因子Ⅱ基因PCR-SSCP多态性分析

采用PCR-SSCP技术检测胰岛素样生长因子Ⅱ(IGF-Ⅱ)基因外显子3和外显子4在松辽黑猪中的单核苷酸多态性,同时研究该基因对松辽黑猪部分重要生长、胴体性状的影响。结果表明:3对引物中,只有p3的扩增片段存在多态性。p3的扩增片段在松辽黑猪中检测到AA、AB和BB 3种基因型;测序分析发现BB型与AA型相比在IGF-Ⅱ基因(AY044828)第21585 bp处有G→C突变,松辽黑猪AA、AB和BB基因型频率分别为0.6956、0.2609和0.0435。AA基因型对瘦肉率(P<0.05)、日增重(P<0.05),BB基因型对平均背膘厚(P<0.01)有正遗传效应,对其他性状差异不明显。     

Analysis of genomic mutation and immunohistochemistry of platelet‐derived growth factor receptors in canine vascular tumours

We examined whether mutation of the platelet‐derived growth factor receptor protein tyrosine kinase (PDGFR)‐α and PDGFR‐β genes contributes to their overexpression in canine vascular tumours. Genomic sequences of trans‐ or juxtamembrane regions of PDGFR‐α and PDGFR‐β were analysed with immunohistochemical staining and polymerase chain reaction‐direct sequencing using DNA from paraffin‐embedded neoplastic tissues of 27 hemangiosarcomas (HSAs) and 20 hemangiomas (HAs). Immunohistochemically, 75% of the HA cases were positive for PDGFR‐α and almost most of the HA cases were negative for PDGFR‐β. Of the HSA cases, 55.6% were negative for PDGFR‐α and 63% were strongly positive for PDGFR‐β. Among the HA cases, 1 missense mutation was detected in PDGFR‐α exon 18 and 1 in PDGFR‐β exon 17. Two HSA cases had missense mutations in exon 14 and 1 in exon 17 of PDGFR‐β. Thus, genomic mutation of trans‐ or juxtamembrane regions of PDGFRs was not the main mechanism driving the activation of receptors in HSA and HA.     

乳牛体型性状线性评定数学模型的指导和应用

本文说明了乳牛体型性状线性评定的常规方法,在此基础上推导出了该评定方法的数学模型。该模型的提出,极大地简化了常规评定方法的繁琐计算,值得在乳牛业生产实践中推广使用。     

Ultrasonographic anatomy of reproductive female leopard geckos (Eublepharis macularius)

Captive leopard geckos (Eublepharis macularius) often present to the exotic clinic for gastrointestinal impactions, follicular stasis, or dystocia. To our knowledge, normal ultrasonographic anatomy of these lizards has not been described. The objectives of this prospective, anatomic, analytical study were to develop ultrasound techniques for this species and to describe the normal sonographic anatomy of the head, coelomic cavity, and tail. Eleven, healthy, female leopard geckos were included. A linear array 13–18 MHz transducer was used. Geckos were sedated and restrained in dorsal recumbency for coelomic structure examination and in ventral recumbency for head and tail examinations. Sagittal and transverse images were acquired and authors recorded qualitative and quantitative ultrasonographic characteristics of anatomic structures. The ventral surface of the lungs, liver, gallbladder, caudal vena cava, portal vein, ventral abdominal vein, aorta, ovarian follicles, fat bodies, tail, and brain were visualized in 10 of 11 individuals. In one individual, molt precluded ultrasonographic examination. The heart, kidneys, urinary bladder, spleen, and pancreas were not visualized. The digestive tract was observed in 10 individuals but was too small to be measured. Findings from the current study could be used as a reference for future studies of leopard geckos.     

The Comet assay for detection of DNA damage in canine sperm

Sperm DNA integrity is a fundamental prerequisite in fertilization and embryo development. Among DNA integrity tests, the Comet assay is an accurate and sensitive test for the detection of sperm oxidative damage. The aim of this work was to evaluate sperm oxidative damage using the Comet assay and to study the correlation between Comet and routine assays for the evaluation of semen quality. Dogs were divided in two groups: group A (n = 6), comprising dogs with abnormal spermiogram, that is astheno‐, terato‐ or oligoasthenoteratozoospermic (OAT); and group B (n = 8), comprising normospermic dogs. The distribution of sperm oxidative damage was significantly different between the two groups (p = .001): group A—median: 31.55%, interquartile range (IQR): 30.18–38.01; group B—median: 0.90%, IQR: 0.65–1.96. The correlation between oxidative damage and abnormal morphology was high (r = .846; p < .001). There was a negative correlation between progressive motility and oxidative damage (r = ?.792; p = .001). Basal and oxidative DNA damage of spermatozoa are increased in dogs with non‐normospermic semen. In conclusion, and considering the elevated correlation with classical tests of sperm quality, the Comet assay has ample potential for clinical and research purposes in dogs.