Seed germination traits of two plant functional groups in the saline deltaic ecosystems

Aims Salt stress resulting from soil salinization is one of the driving forces of the land degradation throughout the world. The modern Yellow River delta is one of the most saline areas in China. Phytoremediation can be an effective way to restore the salinized ecosystems, which requires selecting appropriate plant species. This study explored the germination responses of common plant species from contrasting habitats in the Yellow River delta to varying salinity, offering experimental information for ecosystem restoration in the Yellow River delta.Methods In this study, 15 common plant species from the Yellow River delta were divided into two groups (high-salinity and low-salinity groups) by their natural habitats using Canonical Correlation Analysis. Seeds of each species were treated with five salinity levels (0, 5, 10, 20 and 30 ppt), using a randomized complete block design, and germinated seeds were counted and removed daily for 28 days to calculate the final germination proportion and mean time to germination. The germination responses of seeds to salinity treatments were compared between the two groups.Important findings In relation to salinity, seed germination behavior of the test species was closely related to the salinity level of the habitats over which they were distributed. Species from the habitats with higher salinity had generally higher final germination proportion but shorter mean time to germination than those from the habitats with lower salinity in all of five salinity treatments used. The final germination proportion and mean time to germination of low-salinity group species were more sensitive to salinity than those of high-salinity group species. Selecting the species with high final germination proportion and short mean time to germination is important for restoration of salinized land.     

Lack of synergy for inhibitors targeting a multi-drug-resistant HIV-1 protease

The three-dimensional structures of indinavir and three newly synthesized indinavir analogs in complex with a multi-drug-resistant variant (L63P, V82T, I84V) of HIV-1 protease were determined to approximately 2.2 A resolution. Two of the three analogs have only a single modification of indinavir, and their binding affinities to the variant HIV-1 protease are enhanced over that of indinavir. However, when both modifications were combined into a single compound, the binding affinity to the protease variant was reduced. On close examination, the structural rearrangements in the protease that occur in the tightest binding inhibitor complex are mutually exclusive with the structural rearrangements seen in the second tightest inhibitor complex. This occurs as adaptations in the S1 pocket of one monomer propagate through the dimer and affect the conformation of the S1 loop near P81 of the other monomer. Therefore, structural rearrangements that occur within the protease when it binds to an inhibitor with a single modification must be accounted for in the design of inhibitors with multiple modifications. This consideration is necessary to develop inhibitors that bind sufficiently tightly to drug-resistant variants of HIV-1 protease to potentially become the next generation of therapeutic agents.     

灵芝酸乳制作工艺初探

采用灵芝菌深层培养的滤液 ,可以制成灵芝酸乳 ,经测定 ,灵芝酸乳中可溶性固形物的含量为 11.2 % ,乳酸含量为 0 .72 % ,酸度为 77°T。酸乳同时具有灵芝的药用价值和乳酸饮料的丰富营养。制作工艺简便 ,易于开发     

Establishment and characterization of an immortalized epicardial cell line

Recently, the increasing significance of the epicardium in cardiac development and regeneration is beginning to be recognized. However, because of the small proportion of primary epicardial cells and the limited cell culture time, further research on the mechanism of epicardial cells is hindered. Here, we transfected simian virus 40 Large T (SV40-LT) into primary epicardial cells to establish an immortalized cell line, named EpiSV40. We further demonstrated that EpiSV40 can be easy to culture and has the proliferation, migration and differentiation capacities comparable to primary epicardial cells. EpiSV40 can serve as an ideal in vitro model for epicardial cell research, which will booster the study of the epicardium in cardiac development and heart regeneration.     

同源异型盒基因对血管平滑肌细胞的调控作用

同源异型盒基因是一类对生物体的生长、发育和分化从时间和空间上进行协调的调控基因。构成血管中膜的血管平滑肌细胞表型具有极大的可塑性。在一些病理性血管重构时,血管平滑肌细胞可发生表型调变,从分化型调变为去分化型,具备增殖和迁移能力。在此过程中,多种同源异型盒基因的表达发挥了重要的调控作用。现就同源异型盒基因与血管平滑肌细胞的表型调变、增殖和迁移的关系等方面的研究进展作一综述。     

云南保山猪线粒体DNA D-loop区序列初步分析 Primary Analysis of Mitochondrial DNA D-loop Region Sequence in Baoshan Pig

摘要：为了解云南保山猪(Baoshan pig)的遗传多样性及其遗传背景,我们测定了19个个体线粒体DNA D-loop高变区I 15 363～15 801片段序列438 bp。检测到10种单倍型,包括8个多态位点,其中5次T/C转换、1次G/A转换、1次G/C颠换和1次A/T颠换,其A、T、G、C碱基的平均含量分别为35.4%、26.9%、13.2%和24.5%,A+T含量(62.3%)明显高于G+C含量(37.7%)。对于保山猪的保种及其持续利用有着重要的理论指导意义。 Abstract:To investigate the genetic diversity and genetic data of Baoshan pig in Yunnan province,the mitochondrial DNA D-loop hypervariable segment I sequences 15 363～15 801 (438 bp) in 19 individuals of Baoshan pig were sequenced.Ten mitochondrial haplotypes were identified in the samples,with 8 sites showing polymorphism,which were 5 T/C and 1 G/A transitions,1 G/C and 1 A/T transversions.The contents of A,T,G and C were 35.4%,269%,13.2% and 24.5%,respectively.The content of A+T (62.3%) was significantly higher than that of G+C (37.3%).It will be of importance to conservation and sustainable utilization in Baoshan pig.     

湖南汉族、侗族16对遗传性状的调查

本文对湖南汉族、侗族的16对遗传性状进行了调查.计算出了每对性状的出现率及除扣手和交叉臂外的14对遗传性状的基因频率,分析了民族间和性别间的差异,同时还分析了惯用手、扣手、交叉臂之间的关系。 Abstract:Sixteen genetic traits were investigated in Han and Dong nationalities of Hunan Province.The frequencies of all the sixteen genetic traits and the gene frequencies of fourteen genetic traits except hand-clasping and arm-folding were calculated.The differences between two nationalities and those between male and female were ana-lyzed.The relations among handedness,hand-clasping and arm-folding were also analyzed.     

Identification of p53 Sequence Elements That Are Required for MDM2-Mediated Nuclear Export

It has been demonstrated that MDM2 can differentially regulate subcellular distribution of p53 and its close structural homologue p73. In contrast to MDM2-mediated p53 nuclear export, p73 accumulates in the nucleus as aggregates that colocalize with MDM2. Distinct distribution patterns of p53 and p73 suggest the existence of unique structural elements in the two homologues that determine their MDM2-mediated relocalization in the cell. Using a series of p53/p73 chimeric proteins, we demonstrate that three regions of p53 are involved in the regulation of MDM2-mediated nuclear export. The DNA binding domain (DBD) is involved in the maintenance of a proper conformation that is required for functional activity of the nuclear export sequence (NES) of p53. The extreme C terminus of p53 harbors several lysine residues whose ubiquitination by MDM2 appears to be the initial event in p53 nuclear export, as evidenced by the impaired nucleocytoplasmic shuttling of p53 mutants bearing simultaneous substitutions of lysines 370, 372, 373, 381, 382, and 386 to arginines (6KR) or alanines (6KA). Finally, the region between the DBD and the oligomerization domain of p53, specifically lysine 305, also plays a critical role in fully revealing p53NES. We conclude that MDM2-mediated nuclear export of p53 depends on a series of ubiquitination-induced conformational changes in the p53 molecule that lead to the activation of p53NES. In addition, we demonstrate that the p53NES may be activated without necessarily disrupting the p53 tetramer.     

Preliminary study on a potential panel for quality assurance of ELISPOT

The ELISPOT assay is increasingly used for assessing cellular immune responses in clinical trials of HIV-1 or cancer vaccines. However, to date, data from clinical trials do not consistently show that immune responses are correlated with clinical endpoints. This is due in part to the lack of assay standardization and validation across laboratories and therefore, a quality control panel is required to establish competency and comparability amongst different laboratories. In this study peripheral blood mononuclear cells (PBMCs) from healthy individuals were screened and frozen in liquid nitrogen. The recovery and viability of the PBMCs and the frequencies of interferon (IFN)-γ-secreting cells after CEF peptide pool stimulation were detected after various intervals in seven different laboratories. The recovery and viability did not differ significantly after different intervals. Although the frequencies of IFN (interferon)-γ-secreting cells among thawed PBMCs (peripheral blood mononuclear cells) fluctuated after CEF peptide pool stimulation at different intervals, they were not significantly decreased compared with those among fresh PBMCs. However, the viabilities, recoveries and frequencies of IFN-γ-secreting cells differed significantly among the seven laboratories. Our results indicate that cryopreserved PBMCs could be used as a quality control panel for ELISPOT. However, the procedures for ELISPOT need to be standardized amongst different laboratories.