Production of somatic embryos and shoots from sugarbeet callus: Effects of abscisic acid, other growth regulators, nitrogen source, sucrose concentration and genotype

Summary Two sugarbeet (Beta vulgaris L.) genotypes, REL-1 and REL-2, were used to measure the level of somatic embryo and shoot production from hormone-autonomous callus plated under varied nutrient medium combinations of abscisic acid with the growth regulators 6-benzyladenine, 1-naphthaleneacetic acid, or 2,4-dichlorophenoxyacetic acid, with eight sole nitrogen sources, or with different sucrose concentrations. Clone REL-2 produced embryos up to 35-fold more frequently than clone REL-1. Inclusion of abscisic acid at some concentrations consistently improved embryo production in all experiments and was observed to stimulate shoot production. At some concentrations, 1-naphthaleneacetic acid as well as urea and glutamine stimulated greater embryo production over the control, but only for REL-1, for which there was greater room for improvement. Three and five percent sucrose were superior to 1, 7, and 9%. Higher initial 6-benzyladenine concentration [in the range 0, 0.1−1.0 mg/L (0.44−4.44 μM)] was associated with lower embryo production but greater shoot regeneration for both clones. REL-2 was significantly better than REL-1 in shoot regeneration. The range of embryo production was more than 35-fold between genotypes, whereas the range of physiological effects was no greater than 10-fold. REL-2 has been released to sugarbeet researchers because of its superior embryogenic and shoot regeneration abilities for application in biotechnology.     

Purification and properties of the β-fructofuranosidase from Kluyveromyces fragilis

The β-fructofuranosidase from Kluyveromyces fragilis was purified to one band on electrophoresis by 3 different methods. Two of the preparations were found to be impure by isoelectric focusing. This demonstrates the need for more than one criteria of homogeneity when purifying this enzyme. The enzyme was found to be a glycoprotein, stable at 50°C, with a pH optimum of 4.5. The cations Hg²⁺, Ag⁺, Cu²⁺ and Cd²⁺ exhibited a marked inhibition of the enzyme. Competitive inhibition was observed with the fructose analog 2,5-anhydro-D-mannitol suggesting that the enzyme is inhibited by the furanose form of fructose.     

蝉花虫草活性成分的抗惊厥作用

本研究采用活性追踪的方法,逐步从人工培养蝉花虫草分离获得A（50%乙醇回流提取）、B（膜分离）、C（大孔树脂洗脱）和D（Sephadex LH20柱纯化）等4种样品,单一化合物D纯度为98.62%,鉴定为N6‐(2‐羟乙基)腺苷[N6‐(2‐hydroxyethyl)‐adenosine,HEA]。研究各样品对戊四唑（pentylenetetrazol,PTZ）诱导的小鼠惊厥模型的影响,以及选择性腺苷A1受体（AA1R）拮抗剂DPCPX或选择性腺苷A2A受体（AA2AR）拮抗剂ZM241385对HEA作用的影响,并采用苏木精-伊红（hematoxylin-eosin,HE）染色、免疫组化（immunohistochemical,IHC）染色和蛋白质免疫印迹（Western blot,WB）等技术进一步探究HEA抗惊厥作用的机制。结果表明,各样品（i.p.）均有抗惊厥活性,HEA（40–60mg/kg,i.p.）能显著延长惊厥小鼠的存活时间和降低死亡率,DPCPX（2mg/kg,i.p.）能够拮抗HEA的抗惊厥作用,而ZM241385无此作用;HE、IHC和WB的结果进一步揭示DPCPX显著降低HEA的作用。综上所述,蝉花虫草的HEA具有抗惊厥作用,并且可能通过激活腺苷A1受体而起作用。     

The chimeric cytokine Hyper-IL-6 enhances the efficiency of lentiviral gene transfer in hepatocytes both in vitro and in vivo

Lentiviral vectors have been used for gene transfer into the liver but their ability to efficiently transduce quiescent hepatocytes remains controversial. Lentivirus-mediated gene transfer is more efficient in cycling cells. We determine the effect of H-IL6 in the lentiviral transduction. The lentiviral vector was used to transduce HepG2 cells and mice liver cells, previously treated with H-IL6. The highest transduction level was observed in HepG2 cells treated with 30 ng/mL H-IL6 and in the mice that received 4 μg H-IL6. Our results suggest that H-IL6 is an inducer of lentiviral gene transfer into the liver cells without any toxicity.     

~（60）Co－γ射线诱变柠檬酸产生菌黑曲霉Co9－6的研究

本试验采用￣（６０）Ｃｏ－γ射线对柠檬酸产生菌黑曲霉Ｃｏ９－６进行辐射,经两次处理后选育出Ｌ１２１７和Ｌ８０１两株优良柠檬酸产生菌。中试结果表明菌株Ｌ１２１７较Ｌ８０１更优：产酸率较菌株Ｃｏ９－６提高１７．６％、发酵周期缩短１３．４％、对糖转化率提高１３．３％。     

A DNA Vaccine Encoding a Codon-Optimized Human Papillomavirus Type 16 E6 Gene Enhances CTL Response and Anti-tumor Activity

Summary The HPV oncoproteins E6 and E7 are consistently expressed in HPV-associated cancer cells and are responsible for their malignant transformation. Therefore, HPV E6 and E7 are ideal target antigens for developing vaccines and immunotherapeutic strategies against HPV-associated neoplasms. Recently, it has been demonstrated that codon optimization of the HPV-16 E7 gene resulted in highly efficient translation of E7 and increased the immunogenicity of E7-specific DNA vaccines. Since vaccines targeting E6 also represent an important strategy for controlling HPV-associated lesions, we developed a codon-optimized HPV-16 E6 DNA vaccine (pNGVL4a-E6/opt) and characterized the E6-specific CD8⁺ T cell immune responses as well as the protective and therapeutic anti-tumor effects in vaccinated C57BL/6 mice. Our data indicated that transfection of human embryonic kidney cells (293 cells) with pNGVL4a-E6/opt resulted in highly efficient translation of E6. In addition, vaccination with pNGVL4a-E6/opt significantly enhanced E6-specific CD8⁺ T cell immune responses in C57BL/6 mice. Mice vaccinated with pNGVL4a-E6/opt are able to generate potent protective and therapeutic antitumor effects against challenge with E6-expressing tumor cell line, TC-1. Thus, DNA vaccines encoding a codon-optimized HPV-16 E6 may be a promising strategy for improving the potency of prophylactic and therapeutic HPV vaccines with potential clinical implications.     

Mitogenomic phylogeny of the Percichthyidae and Centrarchiformes (Percomorphaceae): comparison with recent nuclear gene-based studies and simultaneous analysis

Delineation of the fish family Percichthyidae (Percomorphaceae) has a long and convoluted history, with recent morphological-based studies restricting species members to South American and Australian freshwater and catadromous temperate perches. Four recent nuclear gene-based phylogenetic studies, however, found that the Percichthyidae was not monophyletic and was nested within a newly discovered inter-familial clade of Percomorphaceae, the Centrarchiformes, which comprises the Centrarchidae and 12 other families. Here, we reexamined the systematics of the Percichthyidae and Centrarchiformes based on new mitogenomic information. Our mitogenomic results are globally congruent with the recent nuclear gene-based studies although the overall amount of phylogenetic signal of the mitogenome is lower. They do not support the monophyly of the Percichthyidae, because the catadromous genus Percalates is not exclusively related to the freshwater percichthyids. The Percichthyidae (minus Percalates) and Percalates belong to a larger clade, equivalent to the Centrarchiformes, but their respective sister groups are unresolved. Because all recent analyses recover a monophyletic Centrarchiformes but with substantially different intra-relationships, we performed a simultaneous analysis for a character set combining the mitogenome and 19 nuclear genes previously published, for 22 centrarchiform taxa. This analysis furthermore indicates that the Centrarchiformes are divided into three lineages and the superfamily Cirrhitoidea is monophyletic as well as the temperate and freshwater centrarchiform perch-like fishes. It also clarifies some of the relationships within the freshwater Percichthyidae.