Isolation of ScFv antibodies of rP27Kip1 from phage display libraries constructed from immunized and non-immunized repertoires

Through mRNA extract, RT and a series of PCR, phage antibody libraries were constructed from rP27^{kip 1}-immunized and non-immunized mice. After only one round of selection with rP27^{kip 1}, clones from each library were chosen randomly and digested byTag I and Hinf I. 11 of 64 clones from the immunized animal had consistent restriction pattern, while none of the 64 clones from the non-immunized animal had, except that one had the same fragments pattern as that of the 11 clones. The 12 fragments were expressed inE. coli BL21(DE3)/pET-28b(+) system. ELISA showed that some of the fragments could bind to rP27^{kip 1} specifically. AU these results implied that specific antibody can be obtained by genetic engineering without hybridoma or many rounds of growth and panning selection.     

利用离体叶片鉴定杨树耐盐潜力

以受体杨树107和转基因杨树18-1的一年生枝条为材料,采用Hoagland营养液水培方法,添加不同浓度的NaCl,检测二者植株生长以及叶中Na＋和K＋含量的变化。结果表明,在0.6%NaCl处理下18-1生根率明显高于107,生物量较大,叶片中Na＋积累量是107的1.45倍左右。以107和18-1离体叶片为材料,NaCl处理下测定其生理活性指标,发现18-1叶盘的失绿速度和相对电导率都显著低于107叶盘。把离体叶片接种在改良MS培养基上,1.2%NaCl处理可使107叶盘几乎停止伸长,细胞大小不再增加;而18-1叶盘培养7天后伸长了近50%。以上结果表明利用离体叶片可以鉴定出不同基因型杨树的耐盐潜力。     

Dual effects of sodium butyrate on hepatocellular carcinoma cells

Sodium butyrate (NaBu), a histone deacetylase inhibitor, has been shown to inhibit cell growth, induce cell differentiation and apoptosis in multiple cell lines. In present study, we revealed the dual effects of NaBu in regulating hepatocellular carcinoma (HCC) cells. In two different HCC cell lines, SK-Hep1 and SMMC-7721, low concentrations of NaBu induced a significant increase in cell growth ratio and S-phase cell percentage, accompanied by a reduced p21 Cip1 expression at both mRNA and protein levels, while dissimilarly, high concentrations of NaBu inhibited cell growth and induced G1 arrest through up-regulation of p21 Cip1 and p27 Kip1 protein expression. The reduction of p45 Skp2 expression further indicated that the ubiquitin-mediated protein degradation might play a role in NaBu-induced up-regulation of p21 Cip1 and p27 Kip1. Moreover, the high concentration of NaBu was also able to trigger HCC cell apoptosis. Taken together, these results demonstrate the distinct effects of NaBu at different dosages. This finding may contribute to develop more effective tumor therapeutic protocols of NaBu in HCC.     

RAPD重建的大豆属植物的亲缘关系

利用８种ＲＡＰＤ引物（ＯＰＨ－２、ＯＰＨ－３、ＯＰＨ－５、ＯＰＨ－１２、ＯＰＨ－１５、ＯＰＨ－１６、ＯＰＨ－１８和ＯＰＨ－２０）对大豆属的２１份植物材料,其中包括Ｇｌｙｃｉｎｅ亚属的１０个种和Ｓｏｊａ亚属的３个种,进行了基因组指纹图谱构建。通过对获得的基因组指纹图谱的量化分析,利用Ｕｎｗｅｉｇｈｔｅｄｐａｉｒｇｒｏｕｐｗｉｔｈｍａｔｈｅｍａｔｉｃａｖｅｒａｇｅ（ＵＰＧＭＡ）对大豆属中的各个种进行了亲缘关系重建。重建的亲缘关系表明：Ｇ．ｔｏｍｅｎｔｅｌｌａ种中存在３种不同的进化类型,其分化距离已大于某些种种间的分化距离,它们可能是被形态遮蔽的３个种。Ｓｏｊａ亚属内３个种的分化关系同前人的研究推断相同,其亲缘关系很近,这一结果支持将这３个种归并为一个种的观点。但是重建的亲缘关系未能显示出大豆属两个亚属的划分格局。     

Phylogeny of 12 species of genusGlycine Willd. reconstructed with internal transcribed region in nuclear ribosomal DNA

The ITS-Is of 24 accessions belong to 10 species of subgenusGlycine, and 2 species of subgenusSoja of genusGlycine were amplified, cloned and sequenced. According to the homology of the sequences, the phylogeny of the 24 accessions were reconstructed. The reconstructed dendrogram showed that there were some divergent genomic types found in the previously classified species, such asG. tomentella, G. canescens andG. tabacina, and they might be some cryptic species by morphologic analysis.     

草兔的年龄鉴定和种群结构分析

根据１９９１年２－１０月猎自晋东南的２１２只和１９９０－１９９２年狩猎季节猎自山西和陕西省各地的１５１０只草兔眼晶体重的分布规律并参照繁殖资料,确定２２５毫克为区别１年以下及其以上个体的临界重量。秋－冬季种群中,当年兔占８６．３（７２．２－９３．５）％;随着繁殖季节的推移,当年兔的比例逐渐增加。在４０１１只标本中,雌性占５２．３％;其中１２２６只幼体和１９５只成体中分别有雌性５２．４％和５４．４％。在２－９月所获的９１只当年兔有雌性５０．５％,而成体中雌性则有５８．２％。     

Increased glycine betaine synthesis and salinity tolerance in AhCMO transgenic cotton lines

Glycine betaine is an osmoprotectant that plays an important role and accumulates rapidly in many plants during salinity or drought stress. Choline monooxygenase (CMO) is a major catalyst in the synthesis of glycine betaine. In our previous study, a CMO gene (AhCMO) cloned from Atriplex hortensis was introduced into cotton (Gossypium hirsutum L.) via Agrobacterium mediation to enhance resistance to salinity stress. However, there is little or no knowledge of the salinity tolerance of the transgenic plants, particularly under saline-field conditions. In the present study, two transgenic AhCMO cotton lines of the T₃ generation were used to study the AhCMO gene expression, and to determine their salinity tolerance in both greenhouse and field under salinity stress. Molecular analysis confirmed that the transgenic plants expressed the AhCMO gene. Greenhouse study showed that on average, seedlings of the transgenic lines accumulated 26 and 131% more glycine betaine than those of non-transgenic plants (SM3) under normal and salt-stress (150 mmol l⁻¹ NaCl) conditions, respectively. The osmotic potential, electrolyte leakage and malondialdehyde (MDA) accumulation were significantly lower in leaves of the transgenic lines than in those of SM3 after salt stress. The net photosynthesis rate and Fv/Fm in transgenic cotton leaves were less affected by salinity than in non-transgenic cotton leaves. Therefore, transgenic cotton over-expressing AhCMO was more tolerant to salt stress due to elevated accumulation of glycine betaine, which provided greater protection of the cell membrane and photosynthetic capacity than in non-transgenic cotton. The seed cotton yield of the transgenic plants was lower under normal conditions, but was significantly higher than that of non-transgenic plants under salt-stressed field conditions. The results indicate that over-expression of AhCMO in cotton enhanced salt stress tolerance, which is of great value in cotton production in the saline fields.     

Functional analysis of α1,3/4-fucosyltransferase VI in human hepatocellular carcinoma cells

The α1,3/4-fucosyltransferases (FUT) subfamily are key enzymes in cell surface antigen synthesis during various biological processes. A novel role of FUTs in tumorigenesis has been discovered recently, however, the underlying mechanism remains largely unknown. Here, we characterized FUT6, a member of α1,3/4-FUT subfamily, in human hepatocellular carcinoma (HCC). In HCC tissues, the expression levels of FUT6 and its catalytic product SLe(x) were significantly up-regulated. Overexpression of FUT6 in HCC cells enhanced S-phase cell population, promoted cell growth and colony formation ability. Moreover, subcutaneously injection of FUT6-overexpressing cells in nude mice promoted cell growth in vivo. In addition, elevating FUT6 expression markedly induced intracellular Akt phosphorylation, and suppressed the expression of the cyclin-dependent kinases inhibitor p21. Bath application of the PI3K inhibitor blocked FUT6-induced Akt phosphorylation, p21 suppression and cell proliferation. Our results suggest that FUT6 plays an important role in HCC growth by regulating the PI3K/Akt signaling pathway.     

The Arabidopsis Chaperone J3 Regulates the Plasma Membrane H+-ATPase through Interaction with the PKS5 Kinase

The plasma membrane H⁺-ATPase (PM H⁺-ATPase) plays an important role in the regulation of ion and metabolite transport and is involved in physiological processes that include cell growth, intracellular pH, and stomatal regulation. PM H⁺-ATPase activity is controlled by many factors, including hormones, calcium, light, and environmental stresses like increased soil salinity. We have previously shown that the Arabidopsis thaliana Salt Overly Sensitive2-Like Protein Kinase5 (PKS5) negatively regulates the PM H⁺-ATPase. Here, we report that a chaperone, J3 (DnaJ homolog 3; heat shock protein 40-like), activates PM H⁺-ATPase activity by physically interacting with and repressing PKS5 kinase activity. Plants lacking J3 are hypersensitive to salt at high external pH and exhibit decreased PM H⁺-ATPase activity. J3 functions upstream of PKS5 as double mutants generated using j3-1 and several pks5 mutant alleles with altered kinase activity have levels of PM H⁺-ATPase activity and responses to salt at alkaline pH similar to their corresponding pks5 mutant. Taken together, our results demonstrate that regulation of PM H⁺-ATPase activity by J3 takes place via inactivation of the PKS5 kinase.