饲料中添加2%麦饭石对猪生产性能的影响

试验结果显示:生产母猪饲料中添加2%麦饭石,母猪产仔成活率提高21.82%;猪育肥增重试验,断奶仔猪增重提高20.08%,提高饲料报酬34.21%:4月龄育肥猪增重提高18.38%,提高饲料报酬25.58%。     

营养水平对仔猪断奶综合征的影响

试验选取杜×长×大三元杂交仔猪,随机分为2个处理组,每个处理3个重复,每个重复10头仔猪.试验组饲喂5008配合日粮.对照组饲喂5000配合日粮.针对仔猪断奶综合征的表现特征,分别测定各组猪生长性能和腹泻率等指标.试验结果表明,饲粮中合有高水平的蛋白质及能量对断奶仔猪有促生长作用,可缓解仔猪断奶综合征的发生.     

中国荷斯坦牛乳蛋白分子遗传多态性和产奶性状相关性的研究

从北京两个主要牛场共采得１８７头中国荷斯坦奶牛的血样,提取基因组ＤＮＡ,通过ＰＣＲ－ＲＦＬＰ方法对Ｋａｐｐａ酪蛋白、Ｂｅｔａ乳球蛋白（βｌｇ）和Ａｌｐｈａ乳白蛋白（α－ｌａ）进行了基因型的鉴定,并结合产奶性状进行统计分析,结果表明,牛群中上述３种乳蛋白基因的基因频率分别为Ｋ－ｃｎＡ７９％,Ｋ－ｃａＢ２１％,β－ｌｇＡ４３％,β－ｌｇＢ５７％,α－ｌｇＢ１００％,Ｋ－ＣＮ和β－ｌｇ基因位眯对产奶量没     

新城疫病毒结构蛋白功能及检测技术研究进展

新城疫是一种由新城疫病毒引起的烈性传染病,病死率很高,严重危害家禽养殖业,被世界动物卫生组织列为必须报告的动物传染病。在我国,新城疫的暴发和流行虽然已得到了控制,但病毒的变异给新城疫的防控工作带来了困难。新城疫病毒的隐性感染也对我国禽类产品的质量及出口造成了一定影响。因此,明确新城疫病毒各结构蛋白的功能、改进现有检测技术以及开发新的检测技术平台是目前新城疫防控工作的重点。论文对新城疫病毒结构蛋白功能及检测技术的进展进行了系统的阐述。     

顶复门原虫电子转移链代谢及Ⅱ型NADH脱氢酶研究进展

顶复门原虫是包括刚地弓形虫、疟原虫及球虫等在内的一大类寄生性原虫的总称,可引起重要的人畜寄生虫病.抗顶复门原虫药物的长期使用,甚至是滥用,使得这类寄生虫对现有药物产生了明显的抗药性,急需开发新型药物.Ⅱ型NAD(P)H脱氢酶是电子转移链途径中的关键酶,由于其仅存在于某些植物、细菌、真菌和寄生原虫等一些低等生物体内,而在高等动物体内缺失,是研发新型抗感染性药物的重要靶标.笔者主要针对顶复门原虫线粒体电子转移链代谢途径以及Ⅱ型NAD(P)H脱氢酶的研究概况进行综述.     

Ghrelin对雌激素诱导小鼠胸腺萎缩过程中细胞因子及凋亡相关蛋白基因表达的影响

应用光镜和实时定量PCR技术研究了Ghrelin对雌激素诱导小鼠胸腺萎缩过程中胸腺形态学以及部分细胞因子和凋亡相关蛋白基因表达的影响。结果显示,注射Ghrelin后,雌激素诱导的小鼠萎缩胸腺在形态学上基本恢复到正常水平,胸腺中IL-6、TGF-[31、Caspase3、FADDmRNA含量显著降低,Caspase9、FasLmRNA含量略为下降,而IL-7、Bcl-2mRNA含量有所上升。结果表明,Ghrelin可能通过促进胸腺上皮细胞的增殖以及阻断Caspase级联程序和Fas／FasL凋亡信号通路抑制胸腺细胞的凋亡,从而逆转雌激素诱导的小鼠胸腺萎缩。     

Distribution of protein disulfide isomerase during maturation of pig oocytes

Oocyte maturation in mammals is characterized by a dramatic reorganization of the endoplasmic reticulum (ER). In mice, the ER forms accumulations in the germinal vesicle (GV) stage and distinctive cortical clusters in metaphase II (MII) of the oocyte. Multiple evidence suggests that this ER distribution is important in preparing the oocyte for Ca²⁺ oscillations, which trigger oocyte activation at fertilization. In this study, we investigated the time course and illustrated the possible functional role of ER distribution during maturation of porcine oocytes by immunostaining with protein disulfide isomerase (PDI). PDI forms clusters in the cytoplasm of oocytes. After immunostaining, PDI clusters were identified throughout the cytoplasm from the GV to metaphase I (MI) stage; however, at the MII stage, the PDI formed large clusters (1–2 µm) in the animal pole around the first polar body. PDI distribution was prevented by bacitracin, a PDI inhibitor. Our experiments indicated that, during porcine oocyte maturation, PDI undergoes a dramatic reorganization. This characteristic distribution is different from that in the mouse oocyte. Moreover, our study suggested that formation of PDI clusters in the animal pole is a specific characteristic of matured porcine oocytes.     

家蚕表皮蛋白基因的生物信息学分析

家蚕的表皮蛋白(cuticular protein)是家蚕重要的结构蛋白,与几丁质一同作为家蚕表皮的重要组成部分。运用生物信息学的方法对家蚕表皮蛋白进行了广泛分析。通过保守的基序检索家蚕基因组,得到163条候选的表皮蛋白序列,包括RR、Tweedle、CPF&CPFL等家族,并且发现具有确定的保守基序的表皮蛋白基因在染色体上都是以串联集群形式分布。氨基酸组成分析表明,这些表皮蛋白富含甘氨酸、丙氨酸、亮氨酸、组氨酸等。运用Sig-nalP server预测这部分蛋白质有85%都具有信号肽。进化分析显示,负选择是家蚕表皮蛋白基因进化的主要驱动力。采用TFSEARCH等在线服务软件分析发现,在70%含有RR基序的家蚕表皮蛋白基因的核心启动子区具有通用的TATAAA序列。     

Repeat tuberculin skin testing leads to desensitisation in naturally infected tuberculous cattle which is associated with elevated interleukin-10 and decreased interleukin-1 beta responses

The principal surveillance tool used to control bovine tuberculosis in cattle is the removal of animals that provide a positive response to the tuberculin skin-test. In this study we performed a longitudinal investigation of the immunological and diagnostic consequences of repeated short-interval skin-tests in cattle naturally infected with Mycobacterium bovis. Tuberculin skin-test positive cattle were subjected to up to four further intradermal comparative cervical skin-tests at approximately 60-day intervals. A significant progressive reduction in the strength of the skin-test was observed after successive tests. In contrast, the magnitude of interferon-γ (IFN-γ) responses was not influenced by repeat skin-testing either transiently around the time of each skin-test or longitudinally following repeated tests. A significant boost in blood interleukin-10 (IL-10) production was observed within 3 days following each skin-test although the magnitude of this boosted response returned to lower levels by day 10 post-test. The application of a novel multiplex assay to simultaneously measure seven cytokines and chemokines also identified that skin-testing resulted in a significant and progressive reduction in antigen specific interleukin-1β (IL-1β) whilst confirming stable IFN-γ and elevated IL-10 responses in the blood. Therefore, we have demonstrated that in cattle naturally infected with M. bovis, repeat short-interval skin-testing can lead to a progressive reduction in skin-test responsiveness which has potential negative consequences for the detection of infected animals with marginal or inconclusive skin-test responses. The desensitising effect is associated with decreased IL-1β and elevated IL-10 responses, but importantly, does not influence antigen specific IFN-γ responses.