组织培养条件下苹果Ty1-copia类逆转座子的转录活性

研究了苹果基因组中Tyl—copia类逆转座子的转录活性、多样性及其甲基化水平。在培养基MS＋2，4-D2mg／L＋BA0．2mg／L＋NAA0．5mg／L上诱导了1个月的愈伤组织中用RT—PCR方法检测到了270bp的目的条带，而对照、继代组培苗和不含2，4-D的愈伤中均没有目的条带的扩增，说明一定浓度的2，4-D可以诱导苹果中Tyl—copia类逆转座子的表达活性。将目的条带回收、克隆和测序后进行分析：所克隆的21条序列虽都为Tyl-copia类逆转座子逆转录酶保守序列，但存在很大的异质性，21个克隆的核甘酸序列变化范围为196—290bp；翻译成氨基酸后存在缺失、插入、移框和终止密码子突变，7个克隆在氨基酸保守序列‘SLYGLKQ’处有1—2氨基酸位点的突变，说明这些序列对应的逆转录酶多数可能已失去了其原有功能。将21条序列进行聚类分析，除ART20外，其它克隆可聚为3类，并分别与GenBank上某些物种的相应序列同源性很高，表明在不同物种间可能存在逆转座子的横向传递作用。甲基化试验表明苹果基因组内Tyl-copia类逆转座子甲基化水平高。这些都表明Tyl-copia类逆转座子对苹果基因型的多样性及基因组的进化具有重要意义。     

酵母蛋白饲料培养条件的研究

对啤酒酵母进行发酵试验,结果表明:该酵母最优的培养条件是麦芽汁培养基稀释倍数2.5,培养时间20h,蔗糖添加量10Brix,尿素添加量0.02%,且酵母菌耐酸耐铜的性能好。     

蜂花粉营养液的营养成分分析

蜂花粉营养液以油菜花粉和蜂蜜为原料,经过先进的生产工艺制备而成.本文主要对其营养成分进行了分析,该营养液的营养成分搭配合理,含有17种氨基酸,其中包括8种必需氨基酸,氨基酸总量为575.2 mg/100mL;钙31.90 mg/100mL、钾77.46 mg/100mL、钠6.16 mg/100mL、镁19.12 mg/100mL、锌0.14 mg/100mL、铁0.14 mg/100mL、锰0.13 mg/100mL、铜0.053 mg/100mL;尼克酸0.24 mg/100mL、维生素B2 0.01mg/100mL、维生素B6 0.74 mg/100mL、维生素C 0.75 mg/100mL.     

犬胚胎移植手术路径研究性试验

犬胚胎移植手术路径的确定是移植能否成功的关键。我们选择了12例自然发情的母犬，分为供体组和受体组，每组6头。通过生物检测镜确定排卵时间，用腹腔镜观察卵巢黄体发育情况，同时于交配后第9、11、13天剖腹探查，确定冲卵时间。结果于交配后第11天冲洗供体犬左侧子宫角，保留右侧子宫角的两例犬受孕，移植给2头受体犬左侧子宫角。     

不同能量水平日粮对肉仔鸡生长及屠宰性能指标的影响研究

选择3周龄健康、无病、体重无显著差异的肉仔鸡96只,随机分为3组,每组设4 个重复,每个重复8只。分别饲喂蛋白质水平(19．5％)相同而能量水平不同(3．0 Mcal／kg、 3．08 Mcal／kg、3．16Mcal／kg)的3种饲粮。试验结果表明:前两周饲料转化(采食／增重)均以 中能量组(3．08 Mcal／kg)最好,为1．4416±0．1199,但三种不同能量水平对肉仔鸡平均日增 重、平均日耗料、饲料转化率均差异不显著(P>0．05);后两周饲料转化仍以中能量组最好,为 1．6362±0．1346,且显著优于高能量组(P<0．05),而与低能组和中能组之间差异不显著,各 能量处理组蛋白质、粗纤维、钙的代谢率均差异不显著(P>0．05),而磷的代谢率却存在显著 差异(P<0．05),其中,以中等能量组的磷代谢率最高,平均为90．73％;3种能量水平下肉仔鸡 半净膛率、全净膛率均差异不显著(P>0．05),表明能量水平并不影响肉仔鸡屠宰性能。     

应用Nested PCR技术检测柑桔木虱及其寄主九里香的柑桔黄龙病带菌率

应用PCR及Nested PCR技术检测柑桔木虱及其寄主九里香的结果表明:PCR只可检测最低2头带菌木虱,Nested PCR可检测到单个带菌木虱。100头带菌木虱中,单虫检出率为96％。检测田间重、中等、轻病的柑桔园内的木虱,其带菌率依次为87％、53％和21％。在病芦柑上饲菌不同天数的木虱均能检测出带菌,其饲菌时间最短为1d。城市九里香叶片及在其叶上取食的木虱单虫,均能用Nested PCR检测出病原。饲菌木虱接种九里香及芦柑健苗,在植株尚未表现症状时,常规PCR难检测出病原,但用Nested PCR则能检测到病原,说明九里香不仅是木虱的寄主,而且是黄龙病病原的隐症寄主。     

细胞骨架解聚药物对小麦与叶锈菌互作诱发的细胞过敏性反应的影响

 小麦(Triticum aestivum)品种洛夫林10和叶锈菌小种366组成不亲和组合,小麦叶片发生过敏性坏死反应(HR)是小麦抵抗叶锈菌侵染的重要因素。在接种前给小麦叶片分别预注射微管解聚药物磺草硝(oryzalin)和微丝解聚药物细胞松弛素D (cytochalasin D,CD),结果表明2种药物注射使得寄主因叶锈菌侵染诱导的细胞过敏性坏死数目明显减少,并且注射药物的浓度越大,寄主细胞发生HR的数量越少。说明肌动蛋白和微管蛋白的聚合状态是诱发小麦叶片发生HR防卫反应所必需的,细胞骨架在小麦抵抗叶锈菌侵染过程中可能起着重要作用。     

‘新红星’苹果果实蔗糖合酶的活性及亚细胞定位

 在‘新红星’苹果果实发育过程中, 伴随果糖、葡萄糖和蔗糖的积累, 蔗糖合酶的分解活性逐渐下降, 而合成活性逐渐升高。苹果果实的蔗糖合酶由分子量为90 kD 的亚基组成, 其免疫信号强度随发育进程而增加。蔗糖合酶主要定位于果肉细胞的细胞质中, 发育中后期该酶的分布密度有一定增加。综合结果认为, 蔗糖合酶调控发育早期蔗糖的降解和发育后期蔗糖的积累。     

Role of angiotensin II and angiotensin II receptors in vascular smooth muscle cells migration

AIM:To determine the effects of Angiotensin II(AngII) on migration of rat smooth muscle cells and to investigate the mechanisms underlying Ang II action in the development of injured vascular disease. METHODS:VSMCs isolated from aortic media of Wistar rats and cultured by the modified explant method were adopted. In prersence and absence of AngII, the expression of AngII receptor and reorganization of the actin cytoskeleton of VSMCs were studied by immunocytochemistry technique, fluorocytochemistry technique. The migration assays were performed by a modified Boyden's chamber. And the effects of AT₁R antagonist (CV-11974), AT₂R antagonist (PD123319) on aforementioned target were studied.RESULTS:VSMCs migration was stimulated by addition of AngII. The dynamic reorganization of actin cytoskeleton may be an important mechanism by which AngII facilitates VSMC motility. The expression of AT₁R in VSMCs can be upregulated after treatment with AngII initially, then decreased gradually. The expression of AT₁R was downregulated by AT₁R antagonist. The effect of AngII on VSMCs migration was mediated by AT₁R, while AT₂R had no significant effect.CONCLUSION:The dynamic reorganization of actin cytoskeleton is required for AngII-induced VSMC migration, and this effect is mediated by AT₁R .     

Effects of protein kinase C on modulation of vascular endothelium permeability

Protein kinase C pathway is an important intracellular signal transduction pathway. A growing number of evidences showes that activation of PKC influences endothelial cell permeability. In this review, we briefly summarize the effects and regulating pathways of protein kinase C in modulation of vascular endothelium permeability.