分子标记技术在现代猪育种中的应用现状与前景

分子标记技术不仅可以进行猪群体遗传结构的分析,重要的是还可以作为标记辅助选择和标记辅助育种,为猪的早期选种提供新的技术手段和方法。着重概述了分子标记技术及其在猪遗传育种领域中的最新研究进展,并对其应用前景进行了探讨。     

猪生长激素基因与白介素-4基因在小鼠体内的表达效应

比较研究了阳离子脂质体包裹VpGH、VpGH联合VpIL-4以及脂质体(对照)腹腔注射昆明小鼠的增长效应与免疫应答。结果表明:VpGH联合VpIL-4注射小鼠的增重幅度与VpGH注射小鼠相比出现负增长;在血清GH水平上VpGH注射小鼠、VpGH联合VpIL-4注射小鼠两组之间无明显差异;在白细胞数量、红细胞数量上VpGH注射小鼠、VpGH联合VpIL-4注射小鼠两组之间无明显差异。在IgG表达上各组均无显著差异。     

山西瘦肉型猪新品系（SD—Ⅰ）系染色体银染核仁组织区核型分析

（ＳＤ—Ⅰ）系猪银染核仁组织区具有较高的稳定性。其有效银染核仁组织区的位点分布集中在１０号和８号染色体的次缢痕处。当只有一个有效银染发生时，它一定出现在１０号染色体的一条单位上。在本次试验中。仅发现一例其有效银染发生在６号染色体上。有效银染核仁组织区的数量分布在１～４之间，优势银染数目为三。认为细胞悬液保存技术不适于核仁组织区银染处理。     

希罗达治疗晚期结肠癌18例临床分析

目的观察希罗达作为一线药物治疗晚期结肠癌的疗效及安全性.方法对18例具有可测量指标的晚期结肠癌患者采用希罗达2 500 mg/（m^2·d）,分早晚2次服用,用药前予格拉司琼预防呕吐,防止喉痉挛,减少末梢神经副反应,21 d为1周期,完成2周以上评价疗效.18例患者共完成78周期.结果CR 0例,PR 8例（44.4%）,总有效率44.4%,NC 8例（44.5%）,PD 2例（11.1%）.结论希罗达作为一线药物治疗晚期结肠癌有较好疗效,副作用小,特别适宜于年老体弱患者.     

Effect of N-methyl-aspartate and Betaine on Growth Performance and Correlation Between Growth Hormone, Growth Performance and Carcass Composition in Finishing Pigs

［1］Etherton T D. Anabolic effects of porcine somatotropin on pig growth in: Designing foods: Animal product options in the marketplace. National Academy Press, Washington, DC. 1988:194 - 202. ［2］XU Z R, et al. Effect of betaine on carcass characteristics and approach to mechanism of the effect in finishing swine. Acta Veterinaria et Zootechnica Sinica, 1998, 29(5) :397 - 405. (in Chinese) ［3］Knight C D, et al. The performance and carcass composition responses of finishing swine to a range of porcine somatotropin doses in a l-week delivery system. J. Anim. Sci. 1991, 69:4678 - 4689. ［4］Zhou S W, et al. Effect of the recombinant porcine somatotropin on weight gain and carcass composition in swine. Journal of Beijing Agricultural University, 1993, 19: 93 97. (in Chinese) ［5］Danghaday W H. Double effect of growth hormone. Nature,1972..235 - 237. ［6］Estienne M J, et al. N-methyl-D, L-aspartate induced growth bermine secretion in barrows: possible mechanisms of action. J.Anim. Sci. 1996, 74:597- 602. ［7］Barb C R, et al. Aspartate and glutamate modulation of growth bormone secretion in the pig: Possible site of action. Domest.Anim. Endocrinols. 1996, 13:81 - 90. ［8］Lindstrom P, et al. Effect of N-methyl-D, L-aspartate on isotated rat somatotrophs. Endocrinology, 1992, 131: 1903 -1907.     

Expression and Localization of HSPs in the Liver of Transported Pigs

To demonstrate the distribution and expression of heat shock proteins (HSPs) in the liver, five kinds of HSPs, namely HSP70 , HSP72, HSP86, HSP90 and HSP27 were determined after a long distance transport using immunohistochemistry and Western blot. All five HSPs were regularly detected in the liver of both the transported and the control group. Both nuclear and cytoplasmic labeling was present in hepatic cells;however, localization of HSPs was quite different in hepatocytes. The majority of HSP70, HSP72 and HSP27appeared to predominate in cytoplasm of the hepatocytes. Nuclear signals of HSP90 and HSP86 were most prominent in hepatocytes in which immunostaining in the cytoplasm was relatively weak compared with that in the nucleus. There was subjectively lower staining in the edge of hepatic labule, and lower numbers of HSPs labeled hepatic cells corresponded to light microscopic lesions. The obvious inductions of some HSPs were detected in the liver, especially the HSP90(P＜ 0.01) which belongs to the HSP90 family. However, the obvious reductions of HSP86 (P ＜ 0.05), which belong to the HSP90 family, and HSP27 ( P ＜ 0.05), which belong to small families, were detected in stressed pig liver after six hours of long distance transportation.     

猪MB基因外显子3的多态性分析

以MB基因作为影响猪肉肉色的候选基因,利用PCRS-SSCP技术,以野猪、野家杂种猪、民猪、大白猪、长白猪5个猪种为研究对象.根据GenBank上猪的MB序列设计了3对引物,对此基因的3个外显子进行SNPs检测.基因型检测结果表明:MB基因在第1、第2外显子上没有发现多态,在第3外显子上检测到了多态.在第3外显子上的第437 bp处存在一个T→C的碱基突变,该突变未导致氨基酸的改变,属沉默突变.经计算各基因型频率、基因频率和试验统计表明:随野猪、野家杂种猪、民猪、长白猪、大白猪肉色的变浅,等位基因N的基因频率也呈下降趋势.     

蚯蚓与植物联合去除猪粪中的Cu,Zn污染研究

由于饲料添加剂的使用,畜禽粪便中的重金属污染已非常普遍,尤其是Cu,Zn污染最为显著。为此,利用蚯蚓对腐熟猪粪进行处理,再通过植物对蚓粪中Cu,Zn吸收的方法,进行了消除猪粪中重金属的研究。结果表明,蚯蚓对猪粪Zn有较强的吸收能力,富集系数为1.43;而对Cu的吸收能力相对较弱,富集系数为0.61。植物对Cu,Zn的吸收贡献不大,但可以作为饲料返回到动物体内,从而减少饲料添加剂中Cu,Zn的含量。通过蚯蚓与植物的联合处理,能有效地降低腐熟猪粪中Cu,Zn的含量。     

地方品种,外来品种及其杂种猪肉食用品质的研究

本研究结合烹饪加工过程,分别测定了乐平花猪、丹麦长白及其杂种猪生肉、烹饪后肉和加工后肉的还原糖、游离性氨基酸、肌内脂肪和胆固醇等生化成分,目的在于探索地方品种猪食用品质的风味物质基础.结果发现:1.肌内脂肪含量与猪肉保水性能、烹饪加工损失和游离性氨基酸降解有极显著相关,并较大程度影响感官食用品质.因此认为:肌内脂肪是地方品种猪“肉香味美”的重要物质基础.2.乐平花猪生肉游离性氨基酸水平高,加工加热降解程度大.根据迈拉德反应的理论,推测游离性氨基酸作为一种水溶性风味前体物,可能对地方品种肉质特性的形成起一定作用.3.长白猪肉胆固醇和肌内脂肪含量较低于其他两品种.     

凝结芽孢杆菌替代抗生素对猪生产性能的影响

养猪生产中减少抗生素生长促进剂使用量或取消某些抗生素的使用 ,会使猪的生产性能受到严重影响 ,寻找抗生素替代物非常重要。研究表明 ,生长肥育猪饲料中添加凝结芽孢杆菌制剂可显著提高猪的平均日增重 ,降低饲料成本 ,饲养效果与抗菌药利菌净没有显著差异。