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微卫星技术是20世纪80年代末期发展起来的能有效区别不同物种、不同群体及不同基因型个体的分子标记,可作为第二代分子标记。微卫星标记广泛分布于各真核生物基因组中,且随机分布。微卫星DNA(Microsatellite)是一类以1~6 bp的核苷酸为基本单位,呈串联重复状散在分布于整个基因组的重复序列,具有数量多,分布广且均匀,多态性丰富和 相似文献
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据相关研究报道,在澳洲无角陶赛特羊18号染色体末端微卫星标记CSSM18和TGLA122之间的区域有控制其肌肉生长发育的Callipyge和Canvell基因。研究选择了微卫星标记CSSMl8和TGLAl22之间的TGLA122、LS33、ILSTS54、MCMA26四个微卫星标记,测定了新疆引进的澳洲无角陶赛特羊所产后代163只羔羊早期生长发育性状指标,采用PCR—SSCP技术检测了上述4个标记在研究群体中的多态性,分析了研究群体中4个微卫星标记不同基因型与早期生长发育性状的相关性。结果显示:微卫星标记TGLA122的杂合度0.4301,多态信息含量0.2733,有效等位基因数1.3761;微卫星标记MCMA26的杂合度0.4824,多态信息含量0.3660,有效等位基因数1.577O;微卫星标记LS33的杂合度0.3283,多态信息含量0.2744,有效等位基因数1.3780。微卫星标记TGLA122的3种基因型(AA/BB/AB)对90日龄母羔臀宽影响显著(P〈0.05),对其他生长指标均无显著影响;微卫星标记MCMA26的3种基因型(GG/Tr/GT)对60日龄母羔胸围和臀宽有显著影响,对其他生长指标均无显著影响;微卫星标记LS33的2种基因型(EE/EF)个体的体重和体尺均无显著性差异;微卫星标记ILSTS54在该群体中无多态性。 相似文献
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采用微卫星标记多重扩增结合荧光标记检测技术,对152头金华猪种群的30个微卫星位点的不同基因型与生长发育性状的关系进行了初步分析和显著性检测。结果显示SW 2476、SW 0215、SW 24等3个微卫星位点不同基因型间的出生重差异显著;SW 902、S0143、SW 0215、S0228、SW 24等5个微卫星位点不同基因型间的60日龄重差异显著;S0178、S0218、S0255、S0155、SW 951等5个微卫星位点不同基因型的4月龄重差异显著;而S0217微卫星位点的不同基因型的6月龄重差异显著。 相似文献
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微卫星DNA,亦称简单序列重复,是指以2~6个核苷酸为基本序列串联重复的短片段〔1〕。微卫星标记与其它分子标记技术相比,具有分布广泛、多态信息含量高、呈共显性遗传等优点,因此在品种资源分类及畜禽遗传多样性的评估和保存中,微卫星被作为重要的遗传标记之一〔2〕。我国家兔分子生物学标记的研究起步较晚,最近几年才开始,利用微卫星标记来研究家兔的群体遗传特性是在2003年才开始的,相比较而言,国外则开展的较早,技术比较成熟,研究也相对较深入。1国内研究进展殷宝法、魏万红等,使用8对微卫星引物对高原鼠兔血样中的DNA微卫星位点(Sol33… 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
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。 相似文献
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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。 相似文献
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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. 相似文献
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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。 相似文献
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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. 相似文献