家禽miRNA作用机制及研究进展

miRNA是长度约22 nt、具有高度保守性的非编码单链小RNA,通过与靶基因mRNA互补作用,参与调控基因表达及多种生理生化过程。文章综述了近年来miRNA在家禽细胞分化、脂类代谢、生殖生理以及疾病发生等方面的研究,为进一步研究家禽miRNA作用机制提供理论参考。     

家禽miRNA研究进展简

microRNA（miRNA）是近年来研究较为广泛的一种短小RNA,主要功能是调节与个体生长、发育、疾病发生过程有关基因的表达,参与生命过程中一系列重要进程,包括早期发育、细胞增殖、细胞凋亡、脂肪代谢、细胞分化等。作者主要概述了家禽miRNA对胚胎发育、性腺发育、肌肉生长、脂肪代谢的调控作用,并对家禽miRNA的研究前景进行了简单探讨,以期为下一步开展相关研究提供参考。     

基因组学在肠炎沙门菌和禽流感病毒感染家禽研究上的应用

以基因芯片和miRNA深度测序技术相关的基因组学方法对肠炎沙门菌感染家禽中性粒子细胞差异表达基因,以及禽流感病毒感染miRNA表达谱进行了研究,为进一步研究宿主-病原体的互作机制奠定了基础.     

家禽miRNA研究进展

MicroRNA(miRNA)是一类广泛存在于人、动植物和病毒的内源性微小RNA,且在不同组织、不同阶段存在特异性表达,能对细胞凋亡、增殖及分化、神经系统发育、疾病发生、免疫调节等众多生命过程起到重要调控作用。文章综述了miRNA对家禽生长与生殖、疾病调控和脂质代谢等方面的研究进展,为进一步研究miRNA在家禽中功能提供理论依据和事实参考。     

miRNA调控家禽卵泡发育的研究进展

microRNA(miRNA)是一类非编码的、长度约为19~25 nt的单链小分子RNA,广泛存在于真核生物中,对细胞凋亡、增殖与分化、神经系统发育、免疫调节等众多生命过程具有重要的调控作用。文章综述了家禽卵泡发育的特点、调控因素、miRNA与卵泡颗粒细胞及miRNA在家禽卵泡发育中的调控作用等方面的研究进展,为进一步开展miRNA在家禽卵泡发育中的功能提供理论依据和参考。     

miRNA参与调控病毒复制的研究进展

miRNA是1类长度约为22个核苷酸的单链非编码小分子RNA,通过抑制靶基因的转录或降解靶基因mRNA发挥作用.miRNA广泛参与调控细胞生长、凋亡、肿瘤发生以及病毒侵染等过程,通过调控病毒靶基因的表达影响疾病的自然病程和病理、生理过程,已成为研究病毒感染机制的热点.文章综述了miRNA在病毒复制过程中的作用机制研究进...     

microRNA在猪源病毒感染中的作用研究进展

microRNA(miRNA)作为小非编码RNA与特定靶基因mRNA结合,通过降解或抑制其翻译可实现对靶基因表达的调控。深入了解miRNA在猪源病毒与宿主之间的调控作用,对预防和治疗猪病毒性疾病具有重要意义。在此对miRNA的生物合成和作用机制、miRNA与猪源病毒的关系、宿主miRNA与病毒的互作及相关信号通路进行综述,以期为猪病毒性疾病的预防和治疗等提供新思路。     

miRNA调控嗜中性粒细胞和T细胞在呼吸道疾病发生中的作用

正MicroRNA(miRNA)是一类长约19~24 nt的内源性、小型非编码RNA,广泛存在于各种生物体中,miRNA可以通过与靶基因的相互作用,以序列特异性方式调控靶基因的表达,参与多种生理、生化、免疫调控和病理过程[1]。文献显示,在呼吸道疾病的发生发展过程中,miRNA能够通过对免疫系统的调节在炎症反应中扮演重要角色。1 miRNA调控嗜中性粒细胞在呼吸道疾病发生中     

microRNA在骨骼肌发育中的功能及其表达的营养调控

microRNA( miRNA)是真核生物中一类参与调控基因表达的非编码小分子RNA,它通过翻译抑制和使靶mRNA降解,在基因表达中起着负调控作用,与骨骼肌发育、疾病等密切相关.营养可以调控miRNA及其靶基因的表达,这将为更深层次诠释营养素的作用机理提供新的研究方向.本文综述了miRNA的结构和作用机制、骨骼肌miR...     

miRNA可作为马立克氏病病毒感染和肿瘤发生的标记

正鸡马立克氏病是家禽养殖过程中常见的传染性疾病,马立克氏病病毒(MDV)是引发该病的罪魁祸首。新的研究发现,microRNA(miRNA)对MDV肿瘤发生有调节作用。为更深入了解MDV肿瘤发生的分子机制,来自中国农业科学院哈尔滨兽医研究所的科研团队对MDV易感个体的宿主和病毒miRNA表达谱进行了研究。研究人员采用miRNA芯片技术(miRNA芯片分析项目由联川生物承担完成)分析了MDV感染     

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。     

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。     

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

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。     

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。     

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.