成都麻羊乳上皮黏蛋白MUC1的遗传多态性研究

采用SDS-PAGE研究成都麻羊乳上皮黏蛋白MUC1的遗传多态性,并以金堂黑山羊、乐至黑山羊、自贡黑山羊、藏山羊作对照进行比较分析。结果表明:成都麻羊与对照山羊乳MUC1的多态性丰富,成都麻羊有7种基因型、5个等位基因优势基因为C、D、E,金堂黑山羊7种基因型、6个等位基因优势基因为B、C、D,乐至黑山羊6种基因型、6个等位基因优势基因为B、C、D,自贡黑山羊5种基因型、5个等位基因优势基因为A、C、D,藏山羊3种基因型、3个等位基因优势基因为C、D。乳MUC1的基因型、等位基因的分布品种间有差异;根据乳MUC1等位基因频率对供试山羊品种进行聚类分析,成都麻羊与金堂黑山羊的遗传距离最小(D=0.2507)先聚为一类,再依次与乐至黑山羊(D=0.2831)、自贡黑山羊(D=0.3721)、藏山羊(D=0.4752)聚为一大类,结果较好的反映了成都麻羊与对照山羊品种间的亲缘关系。     

２，４-二叔丁基苯酚对啤酒花幼苗生长与光合特性的影响

前期对不同植龄啤酒花根系分泌物及根际土壤的化学物质进行了分离鉴定,结果发现有酚类物质的存在且２,４-二叔丁基苯酚含量较高,为了进一步证实啤酒花是否存在自毒作用,采用田间小区栽培试验,研究了不同用量［０（ＣＫ,Ａ０）,７．５（Ａ１）,１５．０（Ａ２）和２２．５ｍｍｏｌ／ｍ２（Ａ３）］２,４-二叔丁基苯酚处理对啤酒花幼苗生长及光合特性的影响。结果表明,２,４-二叔丁基苯酚用量Ａ１ 和Ａ２ 处理,啤酒花生长好,地上部、地下部、总生物量及日均光合速率均比对照高,且达到显著差异（犘＜０．０５）;２,４-二叔丁基苯酚用量Ａ３ 处理,啤酒花地上部、地下部和总生物量及光合特性均较对照降低,差异达到显著水平（犘＜０．０５）。啤酒花幼苗叶片光合速率日变化呈双峰型,最高峰出现在上午９：００左右,次高峰出现在中午１５：００左右,午间有明显的“午休“现象,与对照（Ａ０）相比,Ａ１、Ａ２、Ａ３ 三个处理的次高峰出现的时间均有推迟,且Ａ１ 和Ａ２ 处理的幼苗午休”现象不太明显,气孔因素是导致其“午休”的主要原因。     

Effects of calcium salts of long-chain fatty acids and rumen-protected methionine on plasma concentrations of ghrelin, glucagon-like peptide-1 (7 to 36) amide and pancreatic hormones in lactating cows

Our objective was to determine the effects of calcium salts of long-chain fatty acids (CLFAs) and rumen-protected methionine (RPM) on plasma concentrations of ghrelin, glucagon-like peptide-1 (7 to 36) amide, and pancreatic hormones in lactating cows. Four Holstein cows in midlactation were used in a 4 by 4 Latin square experiment in each 2-wk period. Cows were fed corn silage-based diets with supplements of CLFAs (1.5% added on dry matter basis), RPM (20 g/d), CLFAs plus RPM, and without supplement. Jugular blood samples were taken from 1 h before to 2 h after morning feeding at 10-min intervals on day 12 of each period. CLFAs decreased dry matter intake, but RPM did not affect dry matter intake. Both supplements of CLFAs and RPM did not affect metabolizable energy intake and milk yield and composition. Plasma concentrations of NEFAs, triglyceride (TG), and total cholesterol (T-Cho) were increased with CLFAs alone, but increases of plasma concentrations of TG and T-Cho were moderated by CLFAs plus RPM. Calcium salts of long-chain fatty acids increased plasma ghrelin concentration, and the ghrelin concentration with CLFAs plus RPM was the highest among the treatments. Plasma concentrations of glucagon-like peptide-1, glucagon, and insulin were decreased with CLFAs, whereas adding RPM moderated the decrease of plasma glucagon concentration by CLFAs. These results indicate that the addition of methionine to cows given CLFAs increases plasma concentrations of ghrelin and glucagon associated with the decrease in plasma concentrations of TG and T-Cho.     

黑色素皮质素受体1(MC1 R)基因与哺乳动物毛色

哺乳动物的有色毛表型要受黑色素皮质素受体1(Melanocortin Receptor1,MC 1 R)位点的不同等位基因调节。MC1R基因的变异与动物的皮毛、人的皮肤和头发颜色差异密切相关。本文对该基因的定位、突变、多态检测及黑色素皮质素受体的作用机制进行了综述。     

德本F1蓝本F1牛适应性分析研究

研究了德国黄牛和比利时蓝牛的杂种后代德本F1、蓝本F1牛在甘肃省陇东地区肉牛带的适应性能,主要包括生长发育、增重、抗病性和繁殖性能等因素。结果表明德本F1、蓝本F1牛在试验期内（0～12月龄）的各项指标均优于本地牛,对当地饲养条件和环境条件表现出了良好的适应能力,可以在当地推广应用。     

口蹄疫病毒VP1基因密码子偏好性分析

VP1蛋白是口蹄疫病毒(FMDV)的主要结构蛋白,可诱导机体产生中和抗体以及激发保护性免疫应答。为探究VP1基因密码子偏好性,筛选出其最佳体外表达系统,使用Visual Gene Developer、CodonW、GraphPad Prism等软件,对VP1基因进行密码子偏好性分析,同时将VP1基因密码子使用频率与大肠杆菌、毕赤酵母、昆虫杆状病毒和哺乳动物细胞表达系统作了比较。结果显示,VP1基因的CAI为0.21,ENC为55.43,GC3S为65.26%,表明该基因密码子使用偏好较弱并且密码子偏好以G/C碱基结尾。结合VP1基因与各表达系统密码子使用频率比值,发现其与昆虫杆状病毒表达系统频率比值差异最小且CAI最大,因此推断昆虫杆状病毒表达系统是FMDV VP1基因最适体外表达系统。本研究为FMDV亚单位疫苗研制等提供了技术基础。     

乳牛口服过量维生素A对维生素D3及钙磷代谢的影响

从北京郊区某农场选取１０头健康成年黑白花乳牛，随机分为试验（５头，每周每头口服维生素Ａ１００万单位）和对照（５头，不作任何处理）两组。８周以后检测发现，试验组血清钙和无机磷水平呈下降趋势；尾椎骨皮质变薄，密度下降，呈现骨质吸收现象；血清碱性磷酸酶显著下降（Ｐ＜０．０５）；其活性代谢产物２５－羟维生素Ｄ３（２５－ＯＨ－Ｄ３）极显著下降（Ｐ＜０．０１）；１，２５－二羟维生素Ｄ３［１，２５－（ＯＨ）２－     

2008-2009年反刍动物营养研究进展 Ⅵ.维生素

作者综述了2008-2009年维生素在反刍动物中的研究进展。维生素A可提高反刍动物的免疫功能,影响反刍动物脂肪组织的发育,具有抗氧化作用;维生素D3能提高奶牛血浆中钙、磷水平,提高血清中25-(OH)D3的浓度,影响牛肉品质;维生素E能提高肉牛的生产性能、奶牛的产奶量,降低繁殖疾病的发病率,刺激生殖器官发育,改善繁殖性能。烟酸能提高牛的生产性能,提高T3、T4水平;叶酸和维生素B12合用能增加牛奶中乳糖、蛋白质及总固形物的产量;胆碱可缓解奶牛产后能量负平衡状态。     

The T allele at the g.1471620G>T in the EDG1 gene associated with high marbling in Japanese Black cattle is at a low frequency in breeds not selected for marbling

Our previous study detected a single nucleotide polymorphism (SNP), g.1471620G > T , in the 5' flanking region of the endothelial differentiation sphingolipid G-protein-coupled receptor 1 ( EDG1 ) gene, which has been considered as a positional functional candidate for the gene responsible for marbling, and showed association of the g.1471620G > T SNP with marbling in Japanese Black beef cattle. In the present study, we investigated the allele frequency distribution of the g.1471620G > T SNP among the 5 cattle breeds, Japanese Black, Japanese Brown, Japanese Short Horn, Holstein, and Brown Swiss breeds. The T allele at the g.1471620G > T SNP associated with high marbling was found at high frequency in Japanese Black breed that has been subjected to a strong selection for high marbling, while the allele was absent or at very low frequencies in the other breeds that have not been strongly selected for high marbling. Based on this finding, we hypothesized that the pressure of the strong selection for high marbling in Japanese Black breed has increased the frequency of the T allele at the g.1471620G > T SNP in the EDG1 .