Identification, mapping, and application of polymorphic DNA associated with resistance gene Pm21 of wheat.

A new powdery mildew resistance gene designated Pm21, from Haynaldia villosa, a relative of wheat, has been identified and incorporated into wheat through an alien translocation line. Cytogenetic and biochemical analyses showed that chromosome arms 6VS and 6AL were involved in this translocation. Random amplified polymorphic DNA (RAPD) analysis was performed on recipient wheat cultivar Yangmai 5, the translocation line, and H. villosa with 180 random primers. Eight of the 180 primers amplified polymorphic DNA in the translocation line, and the same results were obtained in four replications. Furthermore, RAPD analysis was reported for substitution line 6V, seven addition lines (1V-7V), and the F1, as well as F2 plants of (translocation line x 'Yangmai 5'), using two of the eight random primers. One RAPD marker, specific to chromosome arm 6VS, OPH17-1900, could be used as a molecular marker for the detection of gene Pm21 in breeding materials with powdery mildew resistance introduced from H. villosa. Key words : RAPD analysis, 6VS-specific marker, Pm21, Erysiphe graminis f.sp. tritici, Triticum aestivum - Haynaldia villosa translocation.     

Localization of sequences regulating ancestral and acquired sites of esterase6 activity in Drosophila melanogaster

We have broadly defined the DNA regions regulating esterase6 activity in several life stages and tissue types of D. melanogaster using P- element-mediated transformation of constructs that contain the esterase6 coding region and deletions or substitutions in 5' or 3' flanking DNA. Hemolymph is a conserved ancestral site of EST6 activity in Drosophila and the primary sequences regulating its activity lie between -171 and -25 bp relative to the translation initiation site: deletion of these sequences decrease activity approximately 20-fold. Hemolymph activity is also modulated by four other DNA regions, three of which lie 5' and one of which lies 3' of the coding region. Of these, two have positive and two have negative effects, each of approximately twofold. Esterase6 activity is present also in two male reproductive tract tissues; the ejaculatory bulb, which is another ancestral activity site, and the ejaculatory duct, which is a recently acquired site within the melanogaster species subgroup. Activities in these tissues are at least in part independently regulated: activity in the ejaculatory bulb is conferred by sequences between -273 and -172 bp (threefold decrease when deleted), while activity in the ejaculatory duct is conferred by more distal sequences between -844 and -614 bp (fourfold decrease when deleted). The reproductive tract activity is further modulated by two additional DNA regions, one in 5' DNA (-613 to -284 bp; threefold decrease when deleted) and the other in 3' DNA (+1860 to +2731 bp; threefold decrease when deleted) that probably overlaps the adjacent esteraseP gene. Collating these data with previous studies suggests that expression of EST6 in the ancestral sites is mainly regulated by conserved proximal sequences while more variable distal sequences regulate expression in the acquired ejaculatory duct site.      

复方克痛宁临床应用镇痛效果

应用复方克痛宁注射液,治疗各种痛证８２例,显效５０％,有效４３．９％,总有效率９３．９％。其中大多数病例都是经用其它药或疗法无效或效差而用本药获效的。对关节痛、神经血管性头痛等顽固性疼痛显著独特。用药次数最少１次,最多３５例,仅极个别有轻微短暂口干、头晕副作用,各项常规化验检查均无异常,效果显著高于克痛宁或盐酸平痛新单用。临床应用的结果与动物试验观察到的协同增效结果一致。     

丙型肝炎病毒基因组部份NS5区蛋白基因在大肠杆菌中的表达

在大肠杆菌中表达了丙型肝炎病毒基因组ＮＳ５区Ａ段和部份Ｂ段蛋白。ＮＳ５Ａ蛋白溶于水,可经过ＧＳＴ亲和层析柱纯化;ＮＳ５Ｂ蛋白不溶于水,经ＰＢＳ－Ｔｒｉｔｏｎ Ｘ－１００洗涤,尿素溶解后,通过离子交换柱纯化。经ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｍｂｌｏｔ分析,ＮＳ５Ａ蛋白除在５７ｋＤ左右有条带外,还有不同程度的降解产物;ＮＳ５Ｂ蛋白主要在５８ｋＤ左右有条带出现。为查明表达蛋白抗体在病人血清中的分布,取９     

儿童唾液中细菌总数的测定

本文将昆明地区１１－１５岁健康儿童９０名按不同的口腔条件分为三组,每组３０人。采用培养基表面主培养主数法,分别测定唾液中厌氧菌和需氧菌细菌总数。结果表明：儿童唾液中细菌总数,牙颌畸形组、正畸组、正常组,三组间结果在统计学无显著差异。     

植酸钠对黑曲霉柠檬酸发酵产酸的促进效应

研究了植酸钠对黑曲霉柠檬酸发酵产酸的促进效应。在葡萄糖全合成培养基中添加１％的植酸钠,可使产酸比对照提高２．４倍;在薯粉、玉米粉等天然培养基中添加１％植酸钠,柠檬酸产量分别提高１．７倍和１．３倍。酶活性测定分析表明,植酸钠对柠檬酸代谢途径中的几种关键酶的活性有影响。     

Translocation of N-terminal tails across the plasma membrane.

Previously we have shown that the first hydrophobic domain of leader peptidase (lep) can function to translocate a short N-terminal 18 residue antigenic peptide from the phage Pf3 coat protein across the plasma membrane of Escherichia coli. We have now examined the mechanism of insertion of N-terminal periplasmic tails and have defined the features needed to translocate these regions. We find that short tails of up to 38 residues are efficiently translocated in a SecA- and SecY-independent manner while longer tails are very poorly inserted. Efficient translocation of a 138 residue tail is restored and is Sec-dependent by the addition of a leader sequence to the N-terminus of the protein. We also find that while there is no amphiphilic helix requirement for N-terminal translocation, there is a charge requirement that is needed within the tail; an arginine and lysine residue can inhibit or completely block translocation when introduced into the tail region. Intriguingly, the membrane potential is required for insertion of a 38 residue tail but not for a 23 residue tail.     

Transformation of Mycoplasma gallisepticum with Tn916, Tn4001, and integrative plasmid vectors.

Mycoplasma gallisepticum causes respiratory disease in avian species, but little is known about its mechanism(s) of pathogenesis. These studies were undertaken in order to develop genetic systems for analysis of potential virulence factors. M. gallisepticum was transformed with plasmids containing one of the gram-positive transposons Tn916 or Tn4001, which inserted randomly into the mycoplasmal chromosome. Plasmids containing cloned chromosomal DNA were also constructed and tested for integration into regions of DNA homology derived either from chromosomal fragments or from the gentamicin resistance marker from Tn4001. These studies demonstrate that M. gallisepticum is amenable to transformation with both transposons and integrative vectors.     

Phylogenetic relationships among eutherian orders estimated from inferred sequences of mitochondrial proteins: Instability of a tree based on a single gene

The phylogenetic relationships among Primates (human), Artiodactyla (cow), Cetacea (whale), Carnivora (seal), and Rodentia (mouse and rat) were estimated from the inferred amino acid sequences of the mitochondrial genomes using Marsupialia (opossum), Aves (chicken), and Amphibia (Xenopus) as an outgroup. The overall evidence of the maximum likelihood analysis suggests that Rodentia is an outgroup to the other four eutherian orders and that Cetacea and Artiodactyla form a clade with Carnivora as a sister taxon irrespective of the assumed model for amino acid substitutions. Although there remains an uncertainty concerning the relation among Artiodactyla, Cetacea, and Carnivora, the existence of a clade formed by these three orders and the outgroup status of Rodentia to the other eutherian orders seems to be firmly established. However, analyses of individual genes do not necessarily conform to this conclusion, and some of the genes reject the putatively correct tree with nearly 5% significance. Although this discrepancy can be due to convergent or parallel evolution in the specific genes, it was pointed out that, even without a particular reason, such a discrepancy can occur in 5% of the cases if the branching among the orders in question occurred within a short period. Due to uncertainty about the assumed model underlying the phylogenetic inference, this can occur even more frequently. This demonstrates the importance of analyzing enough sequences to avoid the danger of concluding an erroneous tree.     

转译优化对EPO基因在COS7细胞中表达的影响

利用ＣＯＳ７细胞暂时表达系统,研究转译起始序列对ＥＰＯ－ｃＤＮＡ表达的影响。通过ＤＮＡ重组技术,构建了原ＥＰＯ－ｃＤＮＡ表达载体ｐＣＳＶ－ＥＰＯ（１）,其转译起始序列为５＇ＡＡＴＴＣＡＴＧＧ３＇。同时通过定点突变技术,将起始序列改变成５＇ＣＣＡＣＣＡＴＧＧ３＇,而构建了另一表达载体ＰＣＳＶ－ＥＰＯ（２）。后经序列分析证明无误后和前均通过ＤＥＡＥ－ｄｅｘｔｒａｎ法转染ＣＯＳ７细胞上清,测定结果为