Quantitative capillary reversed passive latex agglutination test for C-reactive protein (CRP) in the dog

A capillary reversed passive latex agglutination test (capillary RPLA) was developed which allows quantification of serum C-reactive protein (CRP) within approximately 15 min. The logarithmic regression line (calibration curve) obtained after measuring each CRP concentration three times in twofold dilutions of a standard canine serum containing 222 g/ml of CRP was y=6.394+0.030x (r=0.995). Capillary RPLA permitted quantification of CRP in the range 6.9–222 g/ml. The coefficients of variation ranged from 10.28% to 12.40%. The recovery rates (percentage recovery) of CRP by capillary RPLA were within the range 87% to 106%. On measuring the CRP concentrations in sera from 78 dogs by capillary RPLA, single radial immunodiffusion (SRID) and enzyme-linked immunosorbent assay (ELISA), close correlations were demonstrated between SRID and capillary RPLA (y=7.250+1.109x, r=0.978), between SRID and ELISA (y=3.042+1.059x, r=0.967), and between capillary RPLA and ELISA (y=1.778+0.929x, r=0.962). Capillary RPLA may be considered useful as a routine biochemical technique for measurement of serum CRP concentration in the dog.Abbreviations CRP C-reactive protein - ELISA enzyme-linked immunosorbent assay - RPLA reversed passive latex agglutination test - SRID single radial immunodiffusion     

2015年国外肉牛饲料营养的研究进展

为了全面了解肉牛饲料营养的最新研究进展,作者查阅并总结了2015年关于肉牛饲料营养的国外文献报道,主要从精饲料、粗饲料以及精、粗饲料搭配3个方面进行了综述。精饲料主要包括蛋白质饲料和能量饲料,其中蛋白质饲料的营养研究主要侧重于不同蛋白质饲料对肉牛消化性能、生产性能、酮体特性和肉质以及瘤胃发酵的影响;能量饲料的营养研究侧重于不同类型及加工工艺对肉牛的生产性能、胴体特性以及瘤胃发酵特性的影响;粗饲料的营养研究主要集中于粗料来源及粗料的加工工艺对肉牛生产性能和消化性能两个方面的影响。另外,对精、粗饲料的搭配比例对肉牛生产性能、胴体特性、瘤胃发酵以及采食行为的影响也进行了综述。通过总结和分析肉牛饲料营养的国外研究成果,为中国肉牛业的快速发展提供一定借鉴。     

Physicochemical properties of the thermal gel of water-washed meat in the presence of the more soluble fraction of porcine sarcoplasmic protein

We investigated the physicochemical properties of the thermal gel of water‐washed pork meat (WWM) in the presence of the soluble fraction of porcine sarcoplasmic protein (SP) obtained with ammonium sulfate at 75 percent saturation. Two precipitated fractions of SP were obtained at 0–50 percent and 50–75 percent saturation, named SP‐f1 and SP‐f2, respectively, and the soluble fraction obtained at 75 percent saturation, SP‐f3, was used. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis showed that SP‐f3 contained mainly glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH), while SP‐f1 and SP‐f2 had other SPs such as phosphorylase b, enolase, actin and phosphoglycerate mutase. The gel strength of WWM was greater when SP‐f3 rather than one of various animal proteins such as bovine plasma (BP), egg white, or whey protein isolates (WPI), was added and SP‐f3 had a gel‐enhancing effect as good as that of polyphosphate (PP). The gel strength of WWM with added SP‐f3 increased significantly with NaCl at 0.15 mol/L or more, but not in the absence of NaCl (0 mol/L). The effect of SP‐f3 was evident at neutral pH and maximum gel strength was obtained at a pH above 6.0. Differential scanning calorimetric (DSC) analysis showed that an endothermic peak corresponding to myosin heads in WWM shifted to a lower temperature with the addition of SP‐f3, as in the case of PP, though there was no such shift in the presence of other animal proteins (BP, egg white and WPI), suggesting that SP‐f3 increases the gel strength of WWM through the dissociation of actomyosin similar to PP. Scanning electron microscopy (SEM) revealed wall‐like structures among the protein strands in the WWM gel matrix in the presence of SP‐f3. The results of DSC and SEM indicated that the formation of a gel network in meat products is reinforced with GAPDH in SP after the interaction between GAPDH and myofibrillar protein.     

反刍动物肽营养研究进展

本文综述了反刍动物肽的吸收特点及影响因素,肽的吸收代谢机制,肽对瘤胃微生物的调控及对反刍动物生产性能发挥的作用,以及饲料蛋白源活性肽的开发应用。     

疱疹病毒UL34基因及其编码蛋白的研究进展

论述了疱疹病毒UL34基因的序列特点、编码蛋白结构特点、基本功能以及它与UL31蛋白、Us3蛋白、动力蛋白、核纤层蛋白的相互作用。表明，UL34基因对病毒的早期包装、成熟和出芽以及对UL31蛋白和核纤层蛋白在感染细胞中的正确定位都具有重要作用。     

PrP genotype and lamb birth weight in a scrapie-free environment: Is there an association?

The National Scrapie Plan (NSP) for Great Britain includes selective breeding programmes. These aim to reduce the frequencies of the ovine prion protein (PrP) genotypes at high risk of developing clinical disease (principally those containing the VRQ allele) within the national flock, and select for the low-risk ARR-containing genotypes. The aim of this work was to use available data from embryo transfer programmes in guaranteed scrapie-free environments to investigate whether there was a difference in lamb birth weight associated with the lamb's PrP genotype, which might affect survival. The first analysis utilised data from 355 Cheviot lambs born between 2001 and 2004. The analysis was then repeated using a larger data set of 737 Cheviot, Dorset and Suffolk lambs born between 1999 and 2003. The most important determinants of mean lamb birth weight were litter size, sex and recipient ewe breed, plus lamb breed in the three breed analysis. In both analyses the effects of all these variables are consistent and of the same order of magnitude. In the first analysis there was evidence for an apparent increase in mean lamb birth weight for the ARR-containing genotypes of 0.3 kg (95% C.I. 0.1–0.5 kg). Whereas, in the second data set there was evidence for a decrease in mean lamb birth weight for the VRQ-containing genotypes of − 0.6 kg (95% C.I. − 0.8 to − 0.4 kg). This had been masked in the first analysis by the categorisation of these genotypes with the ARQ/ARQ genotype. Within these flocks, in a scrapie-free environment, neither finding provides support for concerns that selection for low risk ARR-containing genotypes would be detrimental to lamb birth weight, which is considered to be the most important determinant of lamb survival. Extension of this work into field flocks, where scrapie-status cannot be easily assured, will require the collection of sufficient data to adjust for known direct effects as well as any additional potential confounding effects.     

牛分支杆菌MPT83基因的表达及重组蛋白的纯化

从牛分支杆菌培养物中抽提总DNA，扩增了MPT83基因，并克隆入pMD-18-T Simple Vector，将测序正确的目的基因插入表达载体pET-32a（＋）中，转化BL21（DE3）宿主菌，IPTG诱导表达，用亲和层析方法对表达蛋白进行了纯化。经测序，构建的克隆质粒pMD-MPT83与Gen-Bank中的序列一致；构建的表达质粒pET-MPT83经PCR和BamHI＋HindⅢ双酶切鉴定构建正确；经SDS-PAGE分析，在约42ku处出现新的蛋白条带，4h后表达量即达到高峰；Westernblotting分析表明，融合蛋白能够被牛分支杆菌阳性血清所识别；纯化的表达蛋白经SDS-PAGE电泳，出现清晰的单一条带。表明MPT83基因原核表达载体构建成功。     

Overexpression of a small heat‐shock‐protein gene enhances tolerance to abiotic stresses in rice

Rice (Oryza sativa L.) is one of the most important crops in the world which survives from various abiotic stresses in natural environments with specific stress‐involved genes expressed. Plant sHSPs (small heat‐shock proteins) were reported to respond to abiotic stresses. To improve the understanding of sHSPs in rice, we characterized heat‐shock‐protein gene OsHSP18.6 here. OsHSP18.6 could be induced by diverse stresses, such as drought, salt and cold, especially under heat. The gene was found expressed in root, stem, leaf, internode and spikelet. Overexpression of OsHSP18.6 results in increased thermotolerance and exhibits universal tolerance to stresses tested, including heat, drought, salt and cold. Lower levels of malondialdehyde (MDA) and greater activities of catalase (CAT) and superoxide dismutase (SOD) were observed in OsHSP18.6‐overexpression rice under heat and drought. OsHSP18.6‐overexpression lines indicated decreased sterile rates under hot weather without remarkable changes in most of other agronomic traits compared with wild‐type plants.     

Association of RBP‐4 gene polymorphisms with follicular cysts in large white sows

Follicular cysts, which is a common infertility disease, can cause financial losses in pig breeding programmes. The pathogenesis and mechanisms of the formation of follicular cysts are not understood clearly. In our previous study, the concentration of retinol‐binding protein 4 (RBP‐4) in the follicular fluid (FF) of the ovary with follicular cysts was found to be significantly higher than that of normal ovary, thereby suggesting that RBP‐4 may be a candidate biomarker for porcine follicular cysts. To study the association of RBP‐4 and follicular cysts further, we detected the polymorphisms of the RBP‐4 gene and the presence of follicular cysts by PCR‐Restriction fragment length polymorphism (RFLP) assay. In this study, we screened the mutations of RBP‐4 gene in 79 sows with follicular cysts and 100 normal sows without cysts. Results showed that +249‐63G>C polymorphisms were significantly associated with follicular cysts, and sows with CC genotype in RBP‐4 gene had a high risk of developing follicular cysts. Hence, our findings further proved that RBP‐4 may be a novel biomarker for follicular cysts, which may be valuable for the diagnosis of follicular cysts and molecular breeding of pigs.     

绵羊痘病毒E3L蛋白N端结构和功能预测

E3L蛋白是痘病毒的一类早期表达的非结构蛋白,其主要抑制宿主的先天性免疫,与病毒的致病力和宿主嗜性有关,但是目前对绵羊痘病毒E3L蛋白的研究较少。作者运用生物信息学的方法,用已知的E3L蛋白N端结构作为模板,并使用WebLab、SWISS-MODEL和ExPASY等在线软件预测其功能结构域和二、三级结构及氨基酸组成,对其作为Zα潜在家族成员的真实性、可靠性作出理论上的判断。分析结果表明,绵羊痘病毒E3L蛋白N端结构符合Zα家族蛋白的一些基本的结构特征,具有其他E3L蛋白N端相同的功能结构,为该蛋白质N端结构属于Zα蛋白家族提供了一些理论依据。