瑞氏木霉基因组DNA提取方法比较研究

采用4种常规DNA提取方法提取瑞氏木霉基因组DNA。结果表明:EDTA-SDS法和冷冻研磨CTAB 法更适合此真菌DNA的提取,试剂盒提取的总DNA纯度和浓度比较高,但是价格昂贵,冷冻研磨SDS法提取的 DNA浓度不高,不适合分子生物学操作的要求。     

冷冻原肠中细菌基因组DNA提取方法的建立

为建立冷冻原肠中细菌基因组DNA的直接提取法,采用震荡洗脱、金属网过滤和梯度离心相结合的方法,对2份冷冻原肠样品进行前处理;对经前处理后的原肠样品,采用酚/氯仿法提取细菌基因组DNA,然后进行琼脂糖电泳和OD_(260)/OD_(280)比值测定;以细菌基因组DNA为模板,用PCR技术扩增细菌16S rDNA并构建克隆文库,并从2个文库中各随机挑取3个菌落进行16S rDNA的PCR鉴定和DNA测序。结果显示:样品提取的DNA浓度、纯度较高,OD_(260)/OD_(280)比值介于1.8～2.0;挑取的6个菌落中,1个为阴性,剩余5个为阳性,为肠球菌属(Enterococcus)和魏斯氏菌属(Weissella)的5种细菌。结果表明,本研究提取的原肠细菌基因组DNA质量较好,可用于非培养法研究冷冻原肠中细菌的多样性。本研究解决了因缺乏原肠细菌基因组DNA提取方法,无法进一步应用现代分子生物学方法研究冷冻原肠细菌的多样性、菌群组成结构和动态变化等难题。     

牛胚胎冷冻方法的应用研究

为研究使用常规冷冻法和OPS法对牛体内生产胚胎进行冷冻、保存及移植的效果,在阿克苏市进行了牛胚胎冷冻和移植试验.结果显示,这两种方法生产的冻胚解冻后的移植受胎率分别为28.89%和26.08%,差异不显著.对常规冷冻法和OPS法的冻胚生产费用进行比较.结果表明,OPS法冷冻胚胎比常规冷冻法的步骤简单、费用低,不需要专用...     

水牛冷冻精液稀释液中添加复合V_B对精子品质的影响

在水牛冷冻稀释液中添加不同浓度的复合VB,检测其对水牛冷冻精液质量的影响。结果显示,在精液冷冻稀释液中添加3mL/100mL复合VB,可提高水牛精液冷冻复苏后的活力和顶体完整率,对精子的质膜完整性和DNA完整性影响不显著。结果表明,在冷冻稀释液中添加一定浓度的复合VB能够提高水牛冷冻精液质量。     

两种动物组织DNA提取方法的比较

本试验以猪耳组织为试验样本,采用酚-氯仿抽提方法[1]和DNA提取试剂盒方法进行DNA提取的对比试验,并通过核酸蛋白定量仪测量了DNA浓度和纯度,并进行了PCR扩增实验。试验表明,两种提取方法都可以进行PCR扩增试验,但采用试剂盒提取方法提取DNA可以直接进行PCR扩增,而酚-氯仿提取法需放置一段时间后效果好,并且采用试剂盒提取的DNA纯度高、速度快、节省耗材、结果稳定、重复性强,适合大量DNA提取试验。     

哺乳动物胚胎冷冻保存的研究进展

哺乳动物胚胎冷冻保存技术按其进展分为缓慢冷冻法、快速冷冻法和玻璃冷冻法。玻璃化冷冻法又分为常规细管法和OPS法。本文综述了缓慢冷冻法、快速冷冻法以及玻璃化冷冻法的操作过程及所需的抗冻保护剂，并对各种方法的优缺点进行了初步分析。     

桑叶总DNA的斑迹抽提方法

DNA斑迹抽提技术是材料不经研磨和匀浆,直接使用斑迹抽提液提取植物总DNA的一种方法.试验表明,此方法同样适用于桑树等植物DNA的提取,并且效果很好.     

毛细玻管玻璃化冷冻法冷冻保存牛卵母细胞的研究

为了探讨毛细玻管玻璃化冷冻法(GMP)对牛卵母细胞冷冻效果的影响,试验采用毛细玻管玻璃化冷冻法冷冻不同发育阶段的牛卵母细胞,并且对不同预处理方式和玻璃化时间对玻璃化冷冻牛卵母细胞解冻后形态及体外受精卵裂率的影响进行了比较.结果表明:采用毛细玻管玻璃化冷冻法冷冻GV期和体外培养6 h、18 h、22 h各发育阶段的卵母细胞,解冻后体外受精后卵裂率分别是36.67%、40.98%、41.27%、52.38%,前三者之间差异不显著(P>0.05),前三者与培养22 h卵母细胞(52.38%)和对照细胞(68.42%)差异极显著(P<0.01);采用不同浓度的稀溶液预处理卵母细胞,3%乙二醇稀溶液预处理玻璃化前牛卵母细胞可分别获得较高的卵裂率(36.96%);卵母细胞在玻璃化溶液中暴露时间越长受到损伤越严重,暴露30 s能获得最好的玻璃化冷冻效果.     

哺乳动物胚胎冷冻保存研究进展

哺乳动物胚胎冷冻保存效果受冷冻保护剂、冷冻方法、解冻方法等多种因素影响,其中冷冻方法是一个关键性因素.目前胚胎冷冻方法主要有常规慢速冷冻法和玻璃化冷冻法两种.常规慢速冷冻法是指利用甘油、乙二醇等做冷冻保护剂通过缓慢降温的方式进行胚胎冷冻;玻璃化冷冻法是指利用高浓度的冷冻保护剂通过快速降温的方式进行胚胎冷冻.与常规慢速冷冻法相比,玻璃化冷冻法简化了操作过程,大大缩短了操作时间,不需昂贵的程序控制冷冻仪.     

蒙古马肠道细菌总DNA提取方法的比较

本试验采集蒙古马新鲜粪便样品,采用酚－氯仿抽提法和2种细菌基因组DNA提取试剂盒法进行样品中细菌基因组DNA的提取。通过DNA浓度和纯度的测定,并将其作为模板扩增细菌16S rDNA V3区特异性片段对提取效果进行比较,从而找出更适合蒙古马粪便中细菌基因组DNA的提取方法。结果显示,3种提取方法得到的基因组DNA均能用于PCR扩增的模板,其中B试剂盒法提取的DNA数量较多,且纯度高,更适合用于提取蒙古马肠道微生物细菌基因组DNA及后续的蒙古马肠道微生物多样性等分子生物学试验。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

獭兔睾丸的组织学观察

家兔作为一种实验动物 ,推动了繁殖技术的发展。本试验通过对不同年龄公獭兔的睾丸进行组织学观察、测定 ,研究精子的发生规律 ,为系统地进行繁殖生理工作提供依据。1　材料与方法选 60日龄、75日龄、90日龄 3个年龄公獭兔各5只 ,用外科手术法摘取两侧睾丸 ,放入 Bouin氏液中固定 ,二甲苯透明 ,石蜡包埋 ,切成 5～ 8μm切片 ,H.E.染色。在显微镜下观察 ,并进行定量组织学指标测定及差异性比较。2　结果和讨论2 .1　睾丸定量组织学指标的测定结果　见表 1。表 1　獭兔睾丸定量组织学指标　　　μm,个 /精细管60日龄 75日龄 90日龄曲细精管…     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.