不同剂量25羟基维生素D3对断奶前犊牛生长性能、营养物质表观消化率、血浆代谢物及粪便菌群的影响

本试验旨在研究饲粮添加不同剂量25羟基维生素D₃[25(OH)VD₃]对断奶前犊牛生长性能、营养物质表观消化率、血浆代谢物及粪便菌群的影响。选取18头健康、体重[(40.68±1.20)kg]相近的新生荷斯坦犊牛,随机分为3个组,每组6头牛。对照组饲喂基础饲粮,不添加25(OH)VD₃;试验组每头犊牛每天分别在基础饲粮中添加6000(低剂量组)和12000 IU(高剂量组)的25(OH)VD₃。试验期56 d。结果表明:1)与对照组相比,低剂量组和高剂量组体重和平均日增重显著提高(P<0.05),高剂量组体高显著提高(P<0.05),低剂量组和高剂量组粪便评分显著降低(P<0.05)。2)与对照组相比,低剂量组和高剂量组干物质表观消化率显著提高(P<0.05),高剂量组中性洗涤纤维(P=0.05)和钙表观消化率(P<0.05)显著提高。3)与对照组相比,低剂量组和高剂量组血浆25(OH)VD₃和钙含量显著提高(P<0.05),高剂量组血浆磷含量显著提高(P<0.05)。4)与对照组相比,低剂量组和高剂量组血浆白细胞介素-2含量显著降低(P<0.05)。5)与对照组相比,低剂量组和高剂量组粪便中毛螺菌科(Lachnospiraceae)和普雷沃式菌科(Prevotellaceae)相对丰度显著提高(P<0.05),粪便中鼠杆菌科(Muribaculaceae)、克里斯滕森菌科(Christensenellaceae)、螺旋体科(Spirochaetaceae)和未培养_细菌_o_柔膜菌纲_RF39(uncultured_bacterium_o_Mollicutes_RF39)相对丰度显著降低(P<0.05)。由此可见,饲粮添加25(OH)VD₃可以提高断奶前犊牛生长性能,促进营养物质消化吸收,降低炎症反应,改善粪便菌群,降低腹泻发生。     

Effect of dietary fish oil intake on ubiquitin ligase expression during muscle atrophy induced by sciatic nerve denervation in mice

Dietary fish oil intake improves muscle atrophy in several atrophy models however the effect on denervation‐induced muscle atrophy is not clear. Thus, the aim of this study was to investigate the effects of dietary fish oil intake on muscle atrophy and the expression of muscle atrophy markers induced by sciatic nerve denervation in mice. We performed histological and quantitative mRNA expression analysis of muscle atrophy markers in mice fed with fish oil with sciatic nerve denervation. Histological analysis indicated that dietary fish oil intake slightly prevented the decrease of muscle fiber diameter induced by denervation treatment. In addition, dietary fish oil intake suppressed the MuRF1 (tripartite motif‐containing 63) expression up‐regulated by denervation treatment, and this was due to decreased tumor necrosis factor‐alpha (TNF‐α) production in skeletal muscle. We concluded that dietary fish oil intake suppressed MuRF1 expression by decreasing TNF‐α production during muscle atrophy induced by sciatic nerve denervation in mice.     

Involvement of the ERK1/2 MAPK pathway in insulin-induced S6K1 activation in avian cells

In mammals, insulin regulates S6K1, a key enzyme involved in the control of protein synthesis, via the well-documented phosphoinositide-3'kinase (PI3K) pathway. Conversely, S6K1 is activated by insulin in avian muscle despite the relative insulin insensitivity of the PI3K pathway in this tissue. Mitogen-activated protein kinase (MAPK) cascade is another insulin sensitive pathway. The aim of this study was to explore the potential involvement of the ERK1/2 MAPK pathway in the control of p70 S6 kinase (S6K1) in avian species. Firstly, we characterized ERK1/2 MAPK in various chicken tissues. ERK2 was the only isoform detected in avian species whatever the tissue studied. We also showed that ERK2 is activated in vivo by insulin in chicken muscle. The regulation and the role of ERK2 in insulin signaling were next investigated in chicken hepatoma cells (LMH) and primary myoblasts. Insulin stimulation led to ERK2 and S6K1 phosphorylation, and concomitantly increased kinase activity. U0126, an inhibitor of the ERK MAPK pathway, completely abolished insulin-induced S6K1 phosphorylation and activity in chicken myoblasts, whereas its effect was only partial in LMH cells. In conclusion, these results show that ERK1/2 MAPK is involved in the control of S6K1 by insulin in chicken cells, particularly myoblasts.     

3S技术在有蹄类动物栖息地监测中的应用

3S技术是以遥感(RS)、地理信息系统(GIS)、全球定位系统(GPS)为基础,与其他高新技术有机地整合而形成一项新的有蹄类栖息地监测综合方法。全球定位系统(GPS)数据可以显著地提高RS识别地物的能力,为GIS提供数据源。应用地理信息系统(GIS)可以对有蹄类动物栖息地的状况进行评估,自动绘制有蹄类动物的分布图等。遥感(RS)是GIS数据库的数据源。3S技术在将来的野生动物栖息地监测研究中会有更大的发展潜力。     

小剂量砷化物对实验兔生长和繁殖性能的影响

为研究As2O3对实验兔生长和繁殖性能的影响,选择年龄和体重相近的40只实验兔(32只母兔,8只公兔)随机分成4组.对照组饲喂不含As2O3的基础日粮,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组分别饲喂含As2O3 0.5mg/kg、1.0mg/kg和1.5mg/kg的日粮.生长发育和繁殖性能的测定结果显示,试验Ⅰ组与对照组相比,差异不显著(P＞0.05),试验Ⅱ组性能表现优于对照组,差异显著(P＜0.05),试验Ⅲ组出现中毒症状.本实验表明,适量的As2O3对实验兔生长和繁殖具有促进作用.     

A three‐dimensional cell culture system as an in vitro canine mammary carcinoma model for the expression of connective tissue modulators

In this study, derived complex carcinoma (CC) and simple carcinoma (SC) cell lines were established and cultured under two‐dimensional (2D) and three‐dimensional (3D) conditions. The 3D was performed in six‐well AlgiMatrix? (LifeTechnologies®, Carlsbad, CA, USA) scaffolds, resulting in spheroids sized 50–125 µm for CC and 175–200 µm for SC. Cell viability was demonstrated up to 14 days for both models. Epidermal growth factor receptor (EGFR) was expressed in CC and SC in both systems. However, higher mRNA and protein levels were observed in SC 2D and 3D systems when compared with CC (P < 0.005). The connective tissue modulators, metalloproteinases‐1, ‐2, ‐9 and ‐13 (MMPs), relaxin receptors 1 and 2 (RXR1 and RXR2) and E‐cadherin (CDH1) were quantitated. All were upregulated similarly when canine mammary tumour (CMT)‐derived cell lines were cultured under 3D AlgiMatrix, except CDH1 that was downregulated (P < 0.005). These results are promising towards the used of 3D system to increase a high throughput in vitro canine tumour model.     

"兰箭3号"春箭筈豌豆叶绿体全基因组草图及特征分析

箭筈豌豆(Vicia sativa)是自花授粉的二倍体一年生豆科牧草,可为我国高海拔地区的反刍动物提供优质蛋白粗饲料。以"兰箭3号"春箭筈豌豆为研究对象,采用DNase I法纯化叶绿体,利用第二代高通量测序平台Illumina Hiseq2000进行测序,并对"兰箭3号"叶绿体全基因组序列的结构特征进行分析。结果表明,"兰箭3号"叶绿体基因组仅包括一个单拷贝的反向重复序列,其叶绿体全基因组大小为121 883bp,共编码了109个基因,包括4个核糖体RNA(rRNA)基因,29个转运RNA(tRNA)基因,75个蛋白质编码基因和1个假基因。"兰箭3号"在叶绿体基因组结构、基因种类、排列顺序上与其它豆科植物基本一致。其叶绿体全基因组序列已在GenBank注册,序列号为KU053796。"兰箭3号"叶绿体全基因组测序的成功为叶绿体分子生物学研究奠定了基础,并可有效地促进箭筈豌豆遗传育种和分子进化研究。     

鸵鸟红细胞免疫功能研究

应用红细胞Ｃ３ｂ受体花环（Ｃ３ｂＲＲ）和免疫复合物花环（ＩＣＲ）试验,证实鸵鸟红细胞表面存在补体Ｃ３ｂ受体（Ｃ３ｂｒｅｃｅｐｔｏｒ,Ｃ３ｂＲ）,表明红细胞免疫系统（Ｒｃｄｃｅｌｉｍｍｕｎｅｓｙｓｔｅｍ,ＲＣＩＳ）的概念亦适用于这种动物;鸵鸟红细胞不但有传统医学观念上的功能,而且还可借助ＣＲ１（ＣｏｍｐｌｅｍｅｎｔｒｅｃｃｐｔｏｒｔｙｐｅＩ）进行免疫粘附,并以此为基础,表现出各种重要的免疫功能。     

基于表面等离子共振技术鉴定鸡补体受体2与其配体chC3 d的亲和力

鸡补体受体2(Chicken complement receptor 2, chCR2)是一种表达于鸡B淋巴细胞表面的跨膜蛋白,chCR2可以与其生理学配体鸡补体组分3 d(Chicken complement component 3 d, chC3 d)相互作用。目前评估受体与配体亲和力的方法主要有表面等离子共振技术(Surface plasmon resonance, SPR)和生物膜干涉技术(Biolayer interferometry, BLI)等。旨在利用表面等离子共振技术鉴定chCR2受体分子与其配体chC3 d分子的亲和力。成功构建了重组真核表达载体pTT5-chCR2和pTT5-chC3 d;利用HEK 293F表达系统表达了His-chCR2和His-chC3 d蛋白;利用NI柱纯化系统纯化了His-chCR2和His-chC3 d蛋白;利用表面等离子共振技术,通过分析chCR2与chC3 d结合的动力学参数得出两者之间的平衡解离常数KD为1.37μmol/L。结果表明chCR2与其配体chC3 d之间的亲和力较高。     

PA-X基因的长度变化对H3N2犬流感病毒复制能力和致病性的影响

H3N2犬流感病毒(canine influenza virus, CIV)已在中国多地的犬群中流行,是禽流感跨宿主感染并形成新分支的近期案例。研究表明,PA-X基因与甲型流感病毒适应新宿主的能力相关,且其长度能够影响甲型流感病毒的复制及致病能力。为了解PA-X基因的长度变化对H3N2 CIV复制能力及致病力的影响,本研究利用H3N2 CIV的8质粒操作系统,拯救了三株重组H3N2 CIV毒株：PA-X基因表达大小为232个氨基酸多肽的亲本病毒CIV＿PA-X＿232;对PA编码区第191、192位氨基酸的密码子进行改造,PA-X基因不表达蛋白的重组病毒CIV＿PA-X＿Knock;对PA+1编码区第232位氨基酸进行突变,PA-X基因表达大小为252个氨基酸多肽的重组病毒CIV＿PA-X＿252。通过比较3株重组病毒的聚合酶活性,在MDCK细胞中的复制效率及对小鼠致病性的差异,来评价表达不同长度的PA-X基因对H3N2 CIV的影响。结果显示,CIV＿PA-X＿252和CIV＿PA-X＿Knock的聚合酶活性显著(P<0.05)高于CIV＿PA-X＿232,且CIV＿PA-X＿...