兰州大尾羊尾巴的形态特征与断尾方法研究

采用形态观察与组织切片结合的方法对兰州大尾羊的尾巴的形态特征和组织结构进行了研究,并尝试了一种针对兰州大尾羊的外科手术断尾方法.结果表明:兰州大尾羊尾巴是一个扁平的脂肪袋.尾巴的内部结构由4层构成,由表及里,依次是皮肤层、皮下脂肪层、尾椎周围的肌肉层和中心的尾骨.主要血管在尾椎周围的肌束之间.皮下脂肪层很厚,形成了尾巴的主体.尾巴的轴心是尾椎及周围的肌束.断尾手术的要点是:精确确定切口位置,环形切开皮肤和脂肪,将尾椎及其周围的肌束和血管整体结扎,并将这些组织一次性断离.     

Functional characterization of bovine TIRAP and MyD88 in mediating bacterial lipopolysaccharide-induced endothelial NF-κB activation and apoptosis

Mastitis is a prevalent disease in dairy cows. Gram-negative bacteria, which express the pro-inflammatory molecule lipopolysaccharide (LPS), are responsible for the majority of acute clinical cases of mastitis. Previous studies have identified differential susceptibility of human and bovine endothelial cells (EC) to the pro-inflammatory and injury-inducing effects of LPS. The Toll-like receptor (TLR)-4 signaling pathway, which is activated by LPS, has been well studied in humans, but not in ruminants. Human myeloid differentiation-factor 88 (MyD88) and TIR-domain containing adaptor protein (TIRAP) are critical proteins in the LPS-induced NF-κB and apoptotic signaling pathways. To assess the role of the bovine orthologs of these proteins in bovine TLR-4 signaling, dominant-negative constructs were expressed in bovine EC, and LPS-induced NF-κB activation and apoptosis evaluated. The results from this study indicate that bovine MyD88 and TIRAP play functional roles in transducing LPS signaling from TLR-4 to downstream effector molecules involved in NF-κB activation, and that TIRAP promotes apoptotic signaling.     

B细胞异位基因2（Btg2）多态性与河北小尾寒羊多脊椎性状的关联分析

利用直接测序、PCR-RFLP及dCAPS技术研究了河北小尾寒羊(Ouis aries)B细胞异位基因2的外显子3及3'-uTR上的多态性与河北小尾寒羊多脊椎性状的相关性.经测序结果分析,发现了A150G、C243T和A607G 3个单核苷酸多态性,3个位点的PCR-RFLP分析表明,150位点产生AA、AG和GG基因型;243位点产生CC、CT和TT基因型;607位点产生AA、AG和GG基因型.独立性卡方检测结果表明,150位点的不同表型个体基因型频率差异不显著(P>0.05),243位点的差异极显著(P＜0.01),607位点的差异呈显著水平(P<0.05);进一步对这3个位点进行单倍型分析,其独立性卡方检测表明单倍型在不同表型中差异显著(P＜0.05).其结果表明243位点、607位点以及单倍型GTA可能与小尾寒羊多脊椎性状有关.     

特克赛尔肉羊与小尾寒羊的杂交试验

通过特克塞尔公羊与小尾寒羊母羊杂交,产羔率达到213.04%,和对照组小尾寒羊的产羔率230.43%差异不显著;在哺乳期内,特寒F1羔羊的的生长发育指标优于小尾寒羊,胸宽、胸深和尻宽比小尾寒羊高19.95%、11.54%、19.29%（p〈0.01）,4～6月龄育肥期内,特寒F1的净增重为11.77kg,比小尾寒羊的8.51kg提高了38.3%（p〈0.01）,杂交优势明显。特寒FI的胴体重为21.65kg,屠宰率达到51.08%,比小尾寒羊提高5.57个百分点,产肉性能明显优于小尾寒羊,增收111.84元。特寒F1的GR值13.11mm,按新西兰羊肉分级标准,属于中等水平。     

甲基对硫磷水解酶的随机突变和分子对接模拟

甲基对硫磷水解酶(MPH)能高效降解甲基对硫磷,并能够降解杀螟松、乙基对硫磷和毒死蜱,但降解效率依次降低。为提高MPH对毒死蜱的降解活性,采用易错PCR的方法对MPH进行随机突变,筛选到2株突变体A291V和K173R,并对其进行原核表达,结果表明K173R对毒死蜱的降解活性比MPH提高了41.55%。通过同源建模及与毒死蜱的分子对接对酶的结构和功能进行初步分析,结果发现氨基酸残基R72在酶与毒死蜱的结合中起着重要作用。结合口袋和关键氨基酸的变化可最终导致K173R酶活性的提高。     

农产品流通模式研究——基于农户利益视角

随着中国农业的进一步发展,农产品流通已成为制约中国农产品贸易发展的重要瓶颈之一,而农产品流通的关键是小农户与大市场的矛盾问题,笔者选取农户利益的视角,通过对中国目前存在的几种主要的农产品流通体系的现状进行分析研究。     

引入青海省小尾寒羊血清铜蓝蛋白酶活性的测定

用盐酸对苯二胺法对61只引入青海省小尾寒羊进行了测定。结果表明,小尾寒羊血清铜蓝蛋白酶活性为(16.47±8.07)IU/L。公、母组间的血清铜蓝蛋白酶活性差异不显著(P>0.05),但怀孕组的血清铜蓝蛋白酶活性(24.70IU/L)高于未怀孕组的(14.47IU/L),差异极显著(P<0.01)。     

赤泥使用石灰窑尾气脱碱的模拟实验

通过对山西某铝厂赤泥的基础特性分析,提出用含CO2为20%左右的石灰窑尾气对赤泥进行脱碱模拟实验。热力学分析表明利用石灰窑尾气脱碱是可行的,而实际影响脱碱的主要为动力学因素。实验以脱碱率为指标,分析液固比、CO2体积分数、CO2摩尔比、搅拌速度和反应温度5个因素对赤泥脱碱率的影响。研究结果表明,合理的脱碱工艺参数为：液固比8 mL/g、CO2体积分数20%、CO2摩尔比40、搅拌速度400 r/min和反应温度60 ℃,该工艺条件下的脱碱率为31.10%。实验结果表明,可以利用含CO2为20%左右的石灰窑尾气对赤泥进行脱碱处理,该工艺能脱除赤泥中的可溶性碱,符合“以废治废”的循环经济理念。     

Genetic association between DNA fingerprint fragments and loci controlling agriculturally important traits in avocado (Persea americana Mill.)

Summary Associations between DNA fingerprint fragments and 16 avocado quantitative trait loci were tested for in two avocado tamilies by one way analysis of variance and multiple regression analysis. Based on these two analyses the fragments P4, P8, E2 and E5 in Pinkerton × Ettinger progeny were found to be associated with harvest duration, skin color, skin thickness and skin surface, respectively. The fragments P1, P8, B1 and B4 in the Pinkerton × Bacon progeny (half sibs of the original population) were found to be associated with fruit weight, skin color, seed size and peeling, respectively. Based on the original Pinkerton progeny as well as on the half sibs progeny, the fragment P8 was found to be associated with black-purple fruit skin color.The fragment pattern intensity of DNA pools of progeny having either green or black-purple fruit skin color —supported these data. These results are interpreted as genetic-linkage between the DNA fingerprint fragment P8 and locas (1) regulating fruit skin color in avocado.