禽类性别调控机理研究进展

家禽的许多经济性状与性别直接相关,探明家禽的性别调控机理对家禽业具有重要意义。家禽性别分化是一个复杂的过程,除受性染色体上性别决定基因调控外,常染色体上相关基因也参与了性别调控过程。文章主要从禽类的性别分化、性染色体和常染色体上与性腺发育相关基因等方面进行综述,旨在为深入研究禽类的性别调控机理提供参考。     

禽类早期性别鉴定研究进展

从种蛋外型、胚线形态、性腺形态、分子水平、激素水平等方面对禽类早期性别鉴定进行概述,并就其研究进行展望。     

鸟类禽类性别决定的遗传控制及其调控

此文简要回顾了果蝇、鸟类、有袋目动物和真兽亚纲动物的性别决定系统。禽类多倍体、非整数倍体和雌雄嵌合体的材料表明，鸟类性别由Ｚ与常染色体比例决定。限性性状可能同时受细胞自主和激素的双重控制。为确定鸟群的非整倍体，用一个与许多鸟群的Ｚ和Ｗ染色体连锁的ｃＤＮＡ克隆筛选鹦鹉科鸟，发现５只带有非典型的限制性带型。用腹腔镜检查了其中两只，发现是雌雄间体。这些初步观察的结果表明Ｚ、Ｗ染色体的结构变化会导致性别的改变     

鸟类禽类性别决定的遗传控制及其调控

此文简要回顾了果蝇、鸟类、有袋目动物和真兽亚纲动物的性别系统。禽类多倍体、非整数倍体和雌雄嵌合体的材料表明，鸟类性别由Ｚ与常染色体比例决定，。限性性状可能同时受细胞自主和激素的双重控制。为确定鸟群的非整倍体，用一个与许多鸟群的Ｚ和Ｗ染色体体连锁的ＣＤＮＡ克隆筛选鹦鹉科鸟，发现５只带有非典型的了限制性带型。用腹腔镜检查了其中两只，发现是雌雄间体。这些初步观察的结果表明，Ｚ、Ｗ染色体的结构变化会导致性     

禽类恐惧行为遗传调控研究进展

恐惧行为给养禽生产带来经济损失,传统选育方法很难将其淘汰。随着全基因扫描、数量性状定位(QTL)及比较基因组技术的进步,禽类恐惧行为遗传调控研究取得重要进展。禽类恐惧行为存在品种、性别上的差异,通过双向选择已经在鸡、鹌鹑及圆环雉上构建恐惧反应不同的品系。候选基因碱基多样性分析结果表明,血清素、多巴胺受体等基因与恐惧行为相关,但研究结果仍有待进一步验证。鸡全基因组关联分析发现9个染色体37个位点携带恐惧相关基因。禽类恐惧行为遗传调控研究将为品种选育及改良提供支持。     

禽类脂肪细胞分化调控的研究进展

前脂肪细胞是一类具有增殖和定向分化为脂肪细胞能力的前体细胞,其分化受众多基因的调控。目前对哺乳动物脂肪细胞分化的认识比较全面而深入,但是有关禽类脂肪细胞分化相关的研究报道比较少。一方面,禽类脂肪细胞诱导分化方式不同于其他物种,外源脂肪酸是必须的诱导剂之一;另一方面,禽类关键转录因子调控脂肪分化的分子机理不同于哺乳动物,具有特异性。本文综述了禽类前脂肪细胞原代培养、诱导分化方式及其分化调控机制的研究进展,旨在为今后深入了解禽类脂肪分化的机理提供理论参考。     

家蚕性别调控研究进展

通过家蚕的染色体控制模式,从家蚕w染色体的分子结构、W染色体上的性别决定因素、家蚕性别调控级联末端性别分化基因以及家蚕与果蝇doublesex等基因同源的基因等几方面,阐述了家蚕性别调控机理的研究现状。     

禽类就巢发生和调控研究进展

回顾了近20年来对禽类就巢发生的内分泌和神经内分泌研究，并推测能够使用5-羟色胺和多巴胺受体阻断类药物如赛更啶和氯丙嗪缩短家禽的就巢期，或主动免疫血管活性肠肽或催乳素抑制就巢以提高家禽的生产性能。另外对催乳素受体和血管活性肠肽表达调控基因等方面的研究，将有助于最 终发现促进就巢的基因，并利用这些基因选育出具不同就巢习性的家禽品种供应不同的家禽生产用途。     

禽类就巢发生和调控研究进展

回顾了近20年来对禽类就巢发生的内分泌和神经内分泌研究进程及状况,并推测能够使用5-羟色胺和多巴胺受体阻断类药物如赛更啶和氯丙嗪缩短家禽的就巢期,或主动免疫血管活性肠肽或催乳素抑制就巢以提高家禽的生产性能.预计在禽类就巢方面的研究进展将能帮助发现促进就巢的基因,并能利用这些基因选育出具不同就巢习性的家禽品种供应不同的家禽生产用途.     

禽类坏死性肠炎发病机理的研究进展

产气荚膜梭菌引起的禽类坏死性肠炎是家禽养殖业最常见的肠道细菌性疾病之一,其已给全球家禽养殖业造成了巨大的经济损失,严重阻碍了家禽业的健康发展。本文结合近年来的研究成果,重点介绍禽类坏死性肠炎的发病机理及影响因素。     

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。     

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.     

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。 …