乳酸菌用作口服疫苗传递载体的研究

乳酸菌是食品级安全菌,利用乳酸菌为表达载体制成的口服疫苗安全无毒,能诱导机体产生有效的免疫应答和免疫耐受。乳酸菌口服疫苗通过胃肠粘膜进行抗原呈递,使用方便,而且较传统注射途径的免疫效果和依从性好,是理想的疫苗,有广阔的发展前景。     

Genome sequence of <Emphasis Type="Italic">Candida versatilis</Emphasis> and comparative analysis with other yeast

The genome of Candida versatilis was sequenced to understand its characteristics in soy sauce fermentation. The genome size of C. versatilis was 9.7 Mb, the content of G + C was 39.74 %, scaffolds of N50 were 1,229,640 bp in length, containing 4711 gene. There were predicted 269 tRNA genes and 2201 proteins with clear function. Moreover, the genome information of C. versatilis was compared with another salt-tolerant yeast Zygosaccharomyces rouxii and the model organism Saccharomyces cerevisiae. C. versatilis and Z. rouxii genome size was close and both smaller than 12.1 for the Mb of S. cerevisiae. Using the OrthoMCL protein, three genomes were divided into 4663 groups. There were about 3326 homologous proteins in C. versatilis, Z. rouxii and S. cerevisiae.     

Novel polymorphisms of goat growth hormone and growth hormone receptor genes and their effects on growth traits

In this study, the polymorphisms of growth hormone (GH) gene 5' promoter region and intron 8, exons 4 and 10 of growth hormone receptor (GHR) gene were analyzed in Xinong Saanen goats (SG) and Boer goats (BG). Two alleles (A and B) and three genotypes (AA, AB and BB) were detected at P1 locus of GH gene, and two alleles (G and T) and two genotypes (GG and GT) were detected at P4 locus of GHR gene by PCR-SSCP analysis. In addition, two single nucleotide polymorphisms (SNPs)-A73C (P1 locus) and G114T (P4 locus), were identified by DNA sequencing. The frequencies of alleles A and B in the two goat breeds were 0.61-0.62, and 0.39-0.38, respectively, and the frequencies of alleles G and T in the two goat breeds were 0.82-0.86, and 0.18-0.14, respectively. The SNP loci were in Hardy-Weinberg disequilibrium in both goat breeds (P<0.05). Polymorphisms of GH and GHR genes were shown to be associated with growth traits in BG breed. AA and GG genotypes were associated with superior growth traits in 1-, 2- and 3-month old individuals. Hence, AA and GG genotypes are suggested to be a molecular marker for superior growth traits in BG breed.     

The PDZ-GEF Gef26 regulates synapse development and function via FasII and Rap1 at the Drosophila neuromuscular junction

Guanine nucleotide exchange factors (GEFs) are essential for small G proteins to activate their downstream signaling pathways, which are involved in morphogenesis, cell adhesion, and migration. Mutants of Gef26, a PDZ-GEF (PDZ domain-containing guanine nucleotide exchange factor) in Drosophila, exhibit strong defects in wings, eyes, and the reproductive and nervous systems. However, the precise roles of Gef26 in development remain unclear. In the present study, we analyzed the role of Gef26 in synaptic development and function. We identified significant decreases in bouton number and branch length at larval neuromuscular junctions (NMJs) in Gef26 mutants, and these defects were fully rescued by restoring Gef26 expression, indicating that Gef26 plays an important role in NMJ morphogenesis. In addition to the observed defects in NMJ morphology, electrophysiological analyses revealed functional defects at NMJs, and locomotor deficiency appeared in Gef26 mutant larvae. Furthermore, Gef26 regulated NMJ morphogenesis by regulating the level of synaptic Fasciclin II (FasII), a well-studied cell adhesion molecule that functions in NMJ development and remodeling. Finally, our data demonstrate that Gef26-specific small G protein Rap1 worked downstream of Gef26 to regulate the level of FasII at NMJs, possibly through a βPS integrin-mediated signaling pathway. Taken together, our findings define a novel role of Gef26 in regulating NMJ development and function.     

紫胶虫最佳生长地的植被条件分析

本文在对紫胶产区进行调查的基础上,分析了云南紫胶虫最佳生长地的植被条件、对其中的四种群落类型从植物种类成分、群落结构和群落生态等方面进行分析。根据丰富的寄主资源和有利于紫胶虫越冬的气候条件指出“暖热性稀树灌草丛”及“河谷季雨林次生林和灌丛”是云南紫胶虫及其主要寄主植物的适生类型。本文在总结紫胶产区的经验基础上,提出了开发利用的意见和改造的措施。     

Enzymatic synthesis of tea theaflavin derivatives and their anti-inflammatory and cytotoxic activities

Derivatives based on a benzotropolone skeleton (9-26) have been prepared by the enzymatic coupling (horseradish peroxidase/H2O2) of selected pairs of compounds (1-8), one with a vic-trihydroxyphenyl moiety, and the other with an ortho-dihydroxyphenyl structure. Some of these compounds have been found to inhibit TPA-induced mice ear edema, nitric oxide (NO) synthesis, and arachidonic acid release by LPS-stimulated RAW 264.7 cells. Their cytotoxic activities against KYSE 150 and 510 human esophageal squamous cell carcinoma and HT 29 human colon cancer cells were also evaluated.     

Involvement of Inducible 6-Phosphofructo-2-kinase in the Anti-diabetic Effect of Peroxisome Proliferator-activated Receptor γ Activation in Mice

PFKFB3 is the gene that codes for the inducible isoform of 6-phosphofructo-2-kinase (iPFK2), a key regulatory enzyme of glycolysis. As one of the targets of peroxisome proliferator-activated receptor γ (PPARγ), PFKFB3/iPFK2 is up-regulated by thiazolidinediones. In the present study, using PFKFB3/iPFK2-disrupted mice, the role of PFKFB3/iPFK2 in the anti-diabetic effect of PPARγ activation was determined. In wild-type littermate mice, PPARγ activation (i.e. treatment with rosiglitazone) restored euglycemia and reversed high fat diet-induced insulin resistance and glucose intolerance. In contrast, PPARγ activation did not reduce high fat diet-induced hyperglycemia and failed to reverse insulin resistance and glucose intolerance in PFKFB3^+/− mice. The lack of anti-diabetic effect in PFKFB3^+/− mice was associated with the inability of PPARγ activation to suppress adipose tissue lipolysis and proinflammatory cytokine production, stimulate visceral fat accumulation, enhance adipose tissue insulin signaling, and appropriately regulate adipokine expression. Similarly, in cultured 3T3-L1 adipocytes, knockdown of PFKFB3/iPFK2 lessened the effect of PPARγ activation on stimulating lipid accumulation. Furthermore, PPARγ activation did not suppress inflammatory signaling in PFKFB3/iPFK2-knockdown adipocytes as it did in control adipocytes. Upon inhibition of excessive fatty acid oxidation in PFKFB3/iPFK2-knockdown adipocytes, PPARγ activation was able to significantly reverse inflammatory signaling and proinflammatory cytokine expression and restore insulin signaling. Together, these data demonstrate that PFKFB3/iPFK2 is critically involved in the anti-diabetic effect of PPARγ activation.     

Third-order NLO properties of the DMF solutions of 3-D network and 2-D layered organic-metal polymers with (4, 4) grid units

Reactions of 1,1′-(1,4-butanediyl)bis-1H-benzimidazole (bbbm) with Cd(II), Ni(II), or Co(II) afford three organic-metal polymers: {[Cd(bbbm)(SO₄)(H₂O)₂]CH₃OH}_n (1), {[Ni(bbbm)₂(H₂O)₂](NO₃)₂ · 2CH₃OH · 6H₂O}_n (2) and {[Co(bbbm)₂(H₂O)₂](NO₃)₂ · 2CH₃OH · 6H₂O}_n (3). In 1, bbbm and coordinate to Cd(II) simultaneously leading to a 3-D structure. In 2 and 3, each bridging bbbm ligand links two Ni(II) or Co(II) ions forming the 2-D layered structure with (4, 4) grid units. Each (4, 4) grid unit is a 44-membered ring and constructed by four bbbm ligands acting as four sides and four Ni(II) or Co(II) ions representing four corners. Their third-order nonlinear optical (NLO) properties in DMF solution have been studied by Z-scan technique. The results show that the DMF solution of 2 possesses both the large third-order NLO absorptive and strong refractive behaviors; and 3’s shows large NLO absorptive effect and weak NLO refractive behavior. A reasonably good fit between the experimental data and the theoretical curve suggests that the experimentally obtained NLO effects are effective third-order in nature.     

Succession of aquatic macrophytes in the Modern Yellow River Delta after 150 years of alluviation

This study evaluated the succession process of aquatic macrophytes after 150 years of alluviation in the Modern Yellow River Delta, China, and identified the roles of various environmental parameters that regulate vegetation succession. From 2007 to 2008, 214 quadrats were surveyed and 19 environmental parameters were measured, including elevation, plot distance from the seashore, 10 water parameters, and 7 soil parameters. Forty-six aquatic macrophytes belonging to 20 families and 34 genera were identified across the entire delta. Emergent and submerged plants were the most frequent species, accounting for 58.7 and 34.8 % of all species, respectively. Detrended canonical correspondence analysis showed that the presence of aquatic macrophytes in this delta was primarily regulated by water salinity, soil salinity, and distance from the seashore, followed by nutrient concentrations (e.g., NH₄ ⁺, total soil N and PO₄ ^? of water). Salinity-tolerant species (e.g., Ruppia maritima, Phragmites australis, and Typha angustifolia) tended to be widely distributed across the entire delta. In contrast, salinity-sensitive species (e.g., Ceratophyllum demersum, Hydrilla verticillata, and Potamogeton malaianus) tended to be distributed in areas at the early stages of succession, which were relatively distant from the shore. Moreover, this study also confirmed that species richness and diversity were negatively correlated with water and soil salinity, which in turn were negatively correlated with plot distance from the shore. These data indicate that the primary drivers of aquatic macrophyte succession in this delta are water and soil salinity. The information assimilated here is used to propose management practices for the protection of aquatic macrophytes in the Yellow River Delta.