二倍体和四倍体泥鳅线粒体ND-5/6基因多态性的PCR-RFLP分析

采用PCR-RFLP分析方法,对洞庭湖、武汉两地的二倍体和四倍体泥鳅线粒体DNAND-5/6基因多态性及4个群体遗传变异和遗传关系进行了研究。结果表明,120尾泥鳅mtDNAND-5/6扩增片段长度均为2.2kb;从13种限制性内切核酸酶中筛选出6种多态性内切酶(HaeⅢ、DraⅠ、RsaⅠ、TaqⅠ、HinfⅠ、MspⅠ),对扩增产物进行酶切,共检测到66种单倍型。泥鳅群体内单倍型多样性和核苷酸多样性分别为0.7679～0.9385和0.01041～0.03212;其中,洞庭湖二倍体核苷酸多样性最高(0.03212),武汉二倍体其次(0.02452),二倍体群体内核苷酸多样性高于四倍体。群体间的核苷酸多样性(π)大小为0.02588～0.04144,平均值为(0.031737±0.000005)。群体间的核苷酸歧化距离(δ)大小为0.00462～0.01617,平均值为(0.010659±0.000003);其中,武汉二倍体和四倍体之间的核苷酸歧化距离最大(0.01617),武汉四倍体和洞庭湖二倍体之间的核苷酸歧化距离最小(0.00462)。MonteCarlo模拟x2检验表明,4个群体间的单倍型频率存在极...     

胺鲜酯与氯化钙配施对烤烟育苗的影响

以云烟87为材料,研究8%胺鲜酯(DA–6)(质量浓度15.0、10.0、5.0μg/L)与10.0 mmol/L氯化钙配施对烤烟育苗的影响。结果表明：与清水对照相比,播种7d和15d后配施处理的烤烟出苗率分别提高4.50%～10.40%、2.74%～8.33%,成苗率提高3.19%～8.81%;成苗期的苗高、茎基宽、最大叶叶面积分别提高了5.99%～17.66%、1.29%～5.47%、21.1%～73.6%;根、茎、叶、全苗干物质积累量分别提高了25.0%～55.0%、16.7%～33.3%、14.1%～33.8%、16.5%～36.9%,根冠比提高了9.1%～17.0%;配施处理的叶片叶绿素(叶绿素a+叶绿素b)含量增加26.0%～64.9%;配施处理硝酸还原酶活性提高了52.1%～95.9%;过氧化氢酶(CAT)活性、过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量分别降低了41.5%～59.3%、27.9%～62.9%、30.3%～81.1%和34.0%～63.7%,表明用10μg/L DA–6+10 mmol/L氯化钙配施浸种效果最佳。     

低温对2种紫草科植物△6 脂肪酸脱氢酶基因表达的影响

以紫草科植物新疆软紫草(Arnebia euchroma)和假狼紫草(Nonea capsica(willd.)G.Don)为材料,翻译延伸因子EF1a为内参基因,利用半定量逆转录聚合酶链式反应(semi-RT-PCR)技术,对2种紫草植物中γ-亚麻酸合成关键酶基因△6-脂肪酸脱氢酶基因的表达进行研究。结果表明,△6-脂肪酸脱氢酶基因在紫草植物的叶、茎、根中均表达,在低温诱导不同时间后紫草植物叶片中△6-脂肪酸脱氢酶基因的表达有所增强。气相色谱分析显示,其产物γ-亚麻酸在低温下积累,推测紫草科植物叶片中△6-脂肪酸脱氢酶基因表达量增加可能与适应低温胁迫的逆境有关。     

鸡白细胞介素-6原核表达及双抗夹心ELISA方法的建立

应用分子生物学技术原核表达ChIL-6，以ChIL-6重组蛋白为免疫原，按免疫程序分别制备兔抗和鼠抗IL-6重组蛋白的多克隆抗体。应用此抗体建立双抗夹心EL-ISA方法后，为了优化此方法本试验对该方法的最佳试验条件、标准曲线、重复性和初步应用进行确定。结果显示，经SDS-PAGE和Western-blot分析，表明ChIL-6在大肠杆菌中正确表达，为了建立检测ChIL6的双抗夹心ELISA方法，本试验应用表达的重组蛋白制备兔抗和鼠抗多克隆抗体。建立的双抗夹心ELISA方法最佳反应条件为包被抗体的质量浓度为50mg／L，4℃过夜；酶标二抗稀释度为1：400，37。C1h；应用该方法检测感染金黄色葡萄球菌后的ChIL-6，其结果与本实验室之前应用人的ELISA试剂盒检测的结果相似。结果表明，本试验建立的检测ChlL-6的双抗夹心ELISA方法可用于临床。     

GLIS6下用EXCEL数据实现读者信息批量快速导入的方法

为新生读者办理借阅证是高校图书馆流通管理的一个基础环节,如何短时间内为学生办好借阅证,是摆在各家图书馆面前一项急需解决的问题。通过在实践中摸索,找到了一种利用Excel数据,实现读者信息批量快速导入SQL数据库的方法,从而极大地提高了办理借阅证的效率。     

山丹马6-磷酸葡萄糖脱氢酶及葡萄糖磷酸异构酶的多态性研究

用淀粉凝胶电泳及琼脂覆盖技术对山丹马的血液红细胞6磷酸葡萄糖脱氢酶和葡萄糖磷酸异构酶的电泳变异进行了测定。在6磷酸葡萄糖脱氢酶座位发现了3种表现型,即FF,FD和FS,其频率分别为0.958,0.021和0.021。在葡萄糖磷酸异构酶座位发现了两种表现型,即II和FI,其频率分别为0.771和0.229。等位基因频率直接通过表型计算出:PGDF为0.979,PGDD为0.0104,PGDS为0.0104;GPIF为0.1146,GPII为0.8854。亲子关系排除概率在6PGD和GPI座位点分别为0.1009和0.0912。两座位的个体识别概率分别为0.081和0.353。     

Effect of pyrethroids on carbohydrate metabolic pathways in common carp,Cyprinus carpio

The activity levels of succinate dehydrogenase (SDH) and glucose‐6‐phosphate dehydrogenase (G6PD) were assessed in various tissues of Cyprinus carpio var communis which had been exposed to lethal concentrations of group‐II pyrethroids (deltamethrin, cypermethrin, fenvalerate and fluvalinate) for a period of 72 h. The results indicated a steady decrease in SDH activity with a concomitant increase in G6PD activity. The decreased SDH activity indicated inhibition of SDH at mitochondrial level and the increased G6PD activity an enhancement of an alternative pathway of carbohydrate metabolism, viz the hexose monophosphate shunt (HMP) or pentose phosphate pathway as a biochemical adaptation to overcome the toxic stress. © 2001 Society of Chemical Industry     

Effects of N-methyl-D, L-aspartate on secretion of growth hormone-releasing hormone from the boar hypothalamic-preoptic area and median eminence in vitro

N-methyl-D, L-aspartate (NMA) elicited secretion of growth hormone (GH)-releasing hormone from both the hypothalamic-preoptic area and the median eminence that were collected from boars. We suggest that the previously described increase in GH secretion that follows peripheral treatment of swine with NMA is attributable, at least in part, to NMA-stimulated secretion of GH-releasing hormone from the central nervous system.     

Sequences of the 3′ Halves of the Genomes of Barley Yellow Dwarf Virus-PAV cpA Isolates that Vary in Symptom Severity

Barley yellow dwarf virus (BYDV)-PAV isolates from USA have been separated into two distinct clusters (Chay et al. (1996) Virology 219: 57–65; Chay et al. (1996) Phytopathology 86: 370–377). Following this finding we have shown that BYDV-PAV is divided into two groups cpA and cpB based on their coat protein gene sequence, and distinct host preferences (Mastari et al. (1998) Phytopathology 88: 818–821). We have sequenced the complete 3 half of the genomes of two lethal and two mild cpA isolates and compared them with those of several known PAV cpA isolates to assess variability and locate potential determinants of severity. Open reading frames (ORFs) 3, 4, 5, 6 and the 3 untranslated regions had different percent homologies between isolates: ORF5 (92–97%), ORF3 (88–98%) 3-translational enhancer (87–100%) ORF4 (85–99%), 3 untranslated region (72–97%) and ORF6 (61–99%). In contrast to the mild isolates, the field-lethal isolates (FHv1 and FHv2) fell into the same cluster, regardless of the genomic region analysed. The isolates FHv1 and FHv2 differed from mild isolates by eight amino acid substitutions in ORFs 3 and 4, and insertions in ORF5. Four amino acid substitutions in the 17-kDa protein encoded by ORF4 caused a change in local net charge in the field-lethal isolates. Two insertions of four amino acids were identified in the C-terminal half of ORF5 of the field-lethal isolates, but were not present systematically in all lethal isolates analysed. The potential relationships of these differences in predicted amino acid sequences to disease severity are discussed.