SRT1720 enhances maturity and quality of oocytes in aged mice

This study aims to investigate the morphology and distribution of mitochondria, spindles, and chromosomes in oocytes of aged mice and examine the effects of SRT1720 on oocyte maturation. C57BL/6J mice were divided into young (4–8 weeks) and aged groups (48–52 weeks). In vitro maturation media contained (0.05, 0.1, and 1.0 μM) SRT1720 and 0.1-μM dimethyl sulfoxide (DMSO control). The rate of chromosome misalignment and spindle misorientation in oocytes of aged mice were significantly higher than that of young mice (P < 0.01). Fluorescence intensity of mitochondria from oocytes of aged mice was significantly lower than that of young mice (P < 0.01). SRT1720 at 0.1 μM significantly improved oocyte maturation, fertilization, and blastocyst formation in aged mice compared with young mice (P < 0.01). Additionally, immunofluorescence intensity of mitochondria, normal spindle morphology, and chromosome alignment were notably enhanced with SRT1720 when compared with the DSMO control group for metaphase II (MII)-stage oocytes matured in vitro (P < 0.01); 0.1-μM SRT1720 enhanced the expression level of SRIT1 in oocytes from aged mice. In summary, the aged mice oocytes showed increased nuclear and cytoplasmic defects, whereas SRT1720 enhanced oocyte maturation and quality. We concluded that 0.1-μM SRT1720 was an appropriate concentration for in vitro maturation media.     

博落回水提取物对大肠杆菌攻毒断奶仔猪生长性能、腹泻指数和肠道健康的影响

本试验旨在探究饲粮添加博落回水提取物对产肠毒素大肠杆菌（ETEC）攻毒断奶仔猪生长性能、腹泻指数和肠道健康的影响。试验选取30头28日龄健康“杜×长×大”三元杂交断奶仔猪[体重（8.22±0.98） kg],随机分为3个组,每组10个重复,每个重复1头猪。对照组和模型组饲喂基础饲粮,试验组在基础饲粮的基础上添加1 mL/kg的博落回水提取物。预试期3 d,正试期18 d。在正试期第15天,模型组和试验组每只试验猪灌胃10 mL浓度为2×109CFU/mL的ETEC K88菌液,对照组灌胃同一剂量的无菌LB培养液。结果表明：1）第1～14天（攻毒前）,与对照组相比,试验组断奶仔猪平均日增重显著提高（P <0.05）,料重比显著降低（P <0.05）。第15～18天（攻毒后）和整个试验期（第1～18天）,各组断奶仔猪生长性能无显著差异（P>0.05）。2）攻毒后24 h,与对照组相比,模型组断奶仔猪腹泻指数显著提高（P<0.05）;与模型组相比,试验组腹泻指数略有降低,但差异不显著（P>0.05）。攻毒后48 h,与对照组相比,模型组断奶仔猪腹泻指数显著提高（...     

The IMPDH inhibitors,ribavirin and mycophenolic acid,inhibit peste des petits ruminants virus infection

Peste des petits ruminants virus (PPRV) causes highly contagious diseases in domestic and particular wild small ruminants, leading to substantial economic loss. The development of effective and cheap antiviral medications shall help to circumvent this emerging burden. In this study, we found that ribavirin, a competitive inosine-5’-monophosphate dehydrogenase (IMPDH) inhibitor, significantly inhibits the replication of PPRV. As IMPDH is a key enzyme in purine nucleotide synthesis, supplementation of exogenous guanosine attenuate the anti-PPRV effect of ribavirin. Interestingly, an uncompetitive IMPDH inhibitor, mycophenolic acid (MPA), exerted more potent antiviral effect again PPRV. Similarly, this effect was largely restored upon supplementation of guanosine. Thus, we have demonstrated that the IMPDH inhibitors ribavirin and MPA combat PPRV infection through purine nucleotide depletion. Because both regimens have been widely used in the clinic for treating viral infection or organ rejection in transplantation patients for decades, respectively, repurposing these existing safe and cheap medications may provide a new avenue for combating PPRV infection.     

奶牛热应激研究进展

当前以源自北欧的不耐热品种荷斯坦牛作为我国主要的奶用品种遍布全国各地,随着其生产性能的不断提高其热应激的表现也越来越严重。特别是在南方农区热应激造成的经济损失十分明显。因此,研究采取有效的预防措施,消除热应激对奶牛的影响,对保证奶牛高产稳产具有重要的经济意义。     

猪的肌内脂肪生成及其调控

肌内脂肪含量是猪肉食用品质的主要决定因素,尤其对肉的嫩度、风味和多汁性有着重要的影响。肌内脂肪的生成主要受到营养和基因的调控。文中就猪的肌内脂肪的生成及其影响因素作一综述。     

大豆蛋白中的主要抗营养因子对鱼类的影响

<正>鱼粉是鱼类最重要的蛋白源,但其资源短缺是饲料工业面临的最大难题,寻找植物蛋白替代鱼粉蛋白是目前水产行业研究和开发的热点。大豆具有消化吸收率高、氨基酸组成好、价格合理和资源丰富等特点,     

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。     

鸡β-actin基因实时荧光定量PCR方法的建立

根据GenBank上鸡β-actin基因的序列，在保守区域设计并合成一对引物，采用SYBR Green I染料建立了荧光定量PCR法（real-time PCR）。以常规PCR产物为标准品，建立了标准曲线，并进行了熔解曲线分析。结果表明，标准曲线Ct值检测范围为12~31,扩增效率为95.1%；熔解曲线分析结果显示产物特异的单个峰，其Tm为88±0℃，检测周期从RNA提取到荧光定量PCR结束只需4 h。本试验建立的鸡β-actin基因实时荧光定量PCR法扩增效率高、检测范围广、检测周期短，为β-actin基因作为内参基因进行鸡功能基因与病原基因表达的定量分析奠定了基础。     

仔稚鱼营养需求的研究现状

目前,生物饵料依然是仔稚鱼的主要营养来源,商业化生产这些生物饵料需投入大量的设备和人力,而且受自然条件影响很大,所以难于保证培育苗种的需要。因此,大力研究开发营养全面,价格低廉,适合水生动物幼体摄食与消化的人工微粒饲料,以部分或全部替代活饵料,对推动水产养殖业的多     

用鳞片估计马来穿山甲个体数量

我国每年都能查扣到多起非法走私大量马来穿山甲鳞片进入境内的案件,由于不知如何根据鳞片来估计个体数量,而给森林公安机关立案、量刑与处罚带来极大不便。通过统计9头马来穿山甲鳞片的数目（Sm）、鲜重（Sfw）、干重（Sdw）,分别获得了以Sm、Sfw、Sdw为参数来估计马来穿山甲个体数量（N）的3个方程,它们是①Sm/929.8≤N≤Sm/681.8;②Sfw/835.4≤N≤Sfw/389.8;③Sdw/774.3≤N≤Sdw/367.9。执法部门在办理此类走私案件中能通过这些方程方便快捷地估算出走私物品的个体数量,能为同类案件的立案、量刑和处罚提供依据。