Diminishing adenovirus gene expression and viral replication by promoter replacement.

The adenovirus E4 promoter was replaced by a synthetic promoter composed of a minimal TATA box and five consensus 17-mer yeast GAL4-binding-site elements. The viral vectors, which also contained human factor IX (hFIX) cDNA driven by Rous sarcoma virus long terminal repeat in the E1 region, were then constructed and expanded in 293 cells permanently expressing GAL4/VP16 fusion protein. Viral replication and expression of adenovirus E4 genes and late genes (hexon and fiber) were evaluated in vitro in the human lung carcinoma cell line H1299. Viral replication and viral gene expression were dramatically reduced in the cells transduced by vectors with a replaced E4 promoter compared to the levels in the cells transduced by vectors with the wild-type E4 promoter. The levels of transgene (hFIX) expression remained similar between vectors with or without E4 promoter replacement. These results indicate that diminution of viral gene expression and viral replication is achievable by promoter replacement.     

Characterization of streptomyces lydicus WYEC108 as a potential biocontrol agent against fungal root and seed rots.

The actinomycete Streptomyces lydicus WYEC108 showed strong in vitro antagonism against various fungal plant pathogens in plate assays by producing extracellular antifungal metabolites. When Pythium ultimum or Rhizoctonia solani was grown in liquid medium with S. lydicus WYEC108, inhibition of growth of the fungi was observed. When WYEC108 spores or mycelia were used to coat pea seeds, the seeds were protected from invasion by P. ultimum in an oospore-enriched soil. While 100% of uncoated control seeds were infected by P. ultimum within 48 h after planting, less than 40% of coated seeds were infected. When the coated seeds were planted in soil 24 h prior to introduction of the pathogen, 96 h later, less than 30% of the germinating seeds were infected. Plant growth chamber studies were also carried out to test for plant growth effects and for suppression by S. lydicus WYEC108 of Pythium seed rot and root rot. When WYEC108 was applied as a spore-peat moss-sand formulation (10(8) CFU/g) to P. ultimum-infested sterile or nonsterile soil planted with pea and cotton seeds, significant increases in average plant stand, plant length, and plant weight were observed in both cases compared with untreated control plants grown in similar soils. WYEC108 hyphae colonized and were able to migrate downward with the root as it elongated. Over a period of 30 days, the population of WYEC108 colonized emerging roots of germinating seeds and remained stable (10(5) CFU/g) in the rhizosphere, whereas the nonrhizosphere population of WYEC108 declined at least 100-fold (from 10(5) to 10(3) or fewer CFU/g). The stability of the WYEC108 population incubated at 25 degrees C in the formulation, in sterile soil, and in nonsterile soil was also evaluated. In all three environments, the population of WYEC108 maintained its size for 90 days or more. When pea, cotton, and sweet corn seeds were placed into sterile and nonsterile soils containing 10(6) or more CFU of WYEC108 per g, it colonized the emerging roots. After a 1-week growing period, WYEC108 populations of 10(5) CFU/g (wet weight) of root were found on pea roots in the amended sterile soil environment versus 10(4) CFU/g in amended nonsterile soil. To further study the in vitro interaction between the streptomycete and P. ultimum, mycelia of WYEC108 were mixed with oospores of P. ultimum in agar, which was then used as a film to coat slide coverslips.(ABSTRACT TRUNCATED AT 400 WORDS)     

Cytogenetic and genomic relationships ofThinopyrum elongatum with twoPsathyrostachys species and withLeymus secalinus (Poaceae)

Intergeneric hybridizations were made betweenT. elongatum, and twoPsathyrostachys and fiveLeymus species. The seed set obtained onT. elongatum ×Leymus hybrids ranged from 5.65% to 20.00%, depending onLeymus species. The seed set obtained onT. elongatum ×Psathyrostachys hybrids ranged from 16.07% to 19.70%. Meiotic pairing at metaphase-I in JN diploid hybrids ofT. elongatum ×Psathyrostachys species revealed a very low level homology between the basic J and N genomes, and further demonstrated that the two genomes are quite diverged. Chromosome pairing in theT. elongatum ×Leymus secalinus hybrid averaged 15.19 univalents + 2.62 rod bivalents + 0.26 ring bivalents + 0.02 trivalents, suggesting that the partial J^e chromosomes ofT. elongatum has homology withLeymus secalinus genomes.L. secalinus might have 3–4 chromosomes originating from J^e genome.     

Genetic Variation in VP7 Gene of Human Rotavirus Serotype 2 (G2 Type) Isolated in Japan,China, and Pakistan

Sequence analysis of the gene encoding the major neutralization glycoprotein (VP7) was performed on sixteen human isolates of serotype 2 of rotavirus in Japan, China, and Pakistan and their genetic variations were examined. Comparative studies of their nucleotide and deduced amino acid sequences between the sixteen isolates and the HU5 strain revealed an overall homology of more than 94%. A higher degree of homology in nucleotides was observed among the sixteen isolates than between HU5 and the isolates. A total of thirteen amino acid residues frequently converted to another amino acid. Out of the thirteen, five amino acid residues belonging to the major neutralizing epitope regions (C, E, and F in this communication) converted frequently. From the amino acid sequences three subtypes, subtype 1, subtype 2, and intermediate, were suggested to be classified as previously reported for serotype 1 (Xin et al, Virology, 1993, 197: 813-816).     

异源八倍体小冰麦体细胞无性系的建立及其染色体变异

从５个异源八倍体小冰麦（Ｔｒｉｔｉｃｕｍ －Ａｇｒｏｐｙｒｏｎ）的叶片、幼穗及成熟胚诱导愈伤组织,建立体细胞无性系,获得大量再生植株。附加一个冰草染色体组的异源八倍体小冰麦杂种无性系中３７．５％ 表现变异,其中非整倍体植株变异较多,很多变异的再生植株形态与小麦近似,同时出现一定数量染色体重排、交换、易位、断裂、融合等变异。结果表明,通过杂种无性系变异进行染色体基因转化及遗传修饰是一条可行的途径。实验还观察了小冰麦愈伤组织分化过程中绿点的形成过程,首次提出两种类型绿点,即芽绿点和根绿点,并描述了两者的差异     

中枢ACTH受体研究进展

除垂体以外,中枢神经系统也含有促肾上腺皮质激素（ＡＣＴＨ）能神经元,其神经纤维在中枢具有较广泛的投射。ＡＣＴＨ相关肽类在中枢发挥着多种生理功能。近年来对于中枢ＡＣＴＨ受体的研究取得很大的进展,现已确认ＡＣＴＨ结合位点在中枢具有广泛的分布。新近克隆出的四种ＡＣＴＨ受体中,有两种是中枢神经系统占优势的受体亚型。     

Alcohol and aldehyde dehydrogenase genotypes and drinking behavior of Chinese living in Shanghai

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), the principal enzymes responsible for oxidative metabolism of ethanol, exist in multiple, genetically determined molecular forms. Widely different kinetic properties in some of these isozymes account for the individual differences in alcohol sensitivity. In this study we used the polymerase chain reaction/restriction fragment length polymorphism method to determine the genotypes of the ADH2 and ALDH2 loci of alcoholic and nonalcoholic Chinese living in Shanghai. We also investigated the subjects' drinking patterns by means of semistructured interviews. The alcoholics had significantly lower frequencies of the ADH2² and ALDH2² alleles than did the nonalcoholics, suggesting the inhibitory effects of these alleles for the development of alcoholism. In the nonalcoholic subjects, ADH2² had little, if any, effect, despite the significant effect of the ALDH2² allele in decreasing the alcohol consumption of the individual. Taken together, these results fit the proposed hypothesis for the development of alcoholism, i.e., drinking behavior is greatly influenced by the individual's gentoypes of alcohol-metabolizing enzymes, and the risk of becoming alcoholic is proportionate with the ethanol consumption of the individual.     

拉萨郊区藏族的指纹研究

本文报道了拉萨郊区５１７例（男２２６人,女２９１人）藏族健康人的指纹参数正常值、调查分析了指纹类型、指纹组合、指纹指数和指嵴纹计数。比较了藏族不同居群、不同民族和人种间的差异。结果表明,藏族有自己的指纹特点,又显著蒙古人种的一般特征。