心磷脂-细胞色素C体系CD谱的研究

 线粒体内膜中含有特异的心磷脂是细胞色素C氧化酶活性的必需脂。本工作测定了心磷脂脂质体对细胞色素C溶液园二色(CD)谱的影响,发现心磷脂可引起血色素铁的氧化,并使其轴向配位场强的对称性下降。提示心磷脂可能参与酶和底物之间的电子转移过程。     

沿海岛屿与内陆藓类植物遗传多样性和分化的比较研究——以真藓(Bryum argenteum Hedw.)为例

基于11个内陆居群和32个岛屿居群的252份标本,采用ISSR分子标记技术对真藓（Bryum argenteum Hedw.）的遗传多样性进行了研究。结果显示：岛屿与内陆居群间的遗传多样性差异显著,岛屿居群间的分化程度（G_st=0.453）大于内陆居群（G_st=0.387）,岛屿居群的遗传分化与地理来源间存在极显著相关性（r=0.478,n=175,P<0.001）。地理隔离效应是导致岛屿居群间遗传分化的重要因素。岛内居群间的遗传分化水平较低,仅有29.4%~29.7%的遗传多样性存在于居群间。聚类分析表明,43个居群可划分为10大类群,真藓遗传关系受地理因素和生境异质性的影响,水域隔离影响了真藓繁殖体在岛屿间的传播。     

Mitochondrial ND5 12338T>C variant is associated with maternally inherited hypertrophic cardiomyopathy in a Chinese pedigree

Hypertrophic cardiomyopathy is a primary disorder characterized by asymmetric thickening of the septum and left ventricular wall, which affects 1 in 500 individuals in the general population. Mutations in mitochondrial DNA have been found to be one of the most important causes of hypertrophic cardiomyopathy. Here we report the clinical, genetic and molecular characterization of a Han Chinese family with a likely maternally transmitted hypertrophic cardiomyopathy. Four (2 men/2 women) of 5 matrilineal relatives in this 3-generation family exhibited the variable severity and age at onset of 44 to 79years old. Sequence analysis of the entire mitochondrial DNA in this pedigree identified the known homoplasmic ND5 12338T>C variant. This mitochondrial DNA haplogroup belongs to the Eastern Asian F2a. The 12338T>C variant, highly evolutionarily conserved, resulted in the replacement of the translation initiating methionine with a threonine, shortening the ND5 polypeptide by 2 amino acids. The occurrence of ND5 12338T>C variant exclusively in maternal members of this Chinese family suggested that the 12338T>C variant is associated with maternally inherited hypertrophic cardiomyopathy. Our findings will provide theoretical basis for genetic counseling of maternally inherited hypertrophic cardiomyopathy.     

Genotypic diversity enhances invasive ability of Spartina alterniflora

Although genetic diversity is very important for alien species, which have to cope with new environments, little is known about the role that genetic diversity plays in their invasive success. In this study, we set up a manipulation experiment including three levels of genotypic diversity to test whether genotypic diversity can enhance the invasive ability of alien species, in our case the invasive Spartina alterniflora in China, and to infer the underlying mechanisms. There was no significant relationship between genotypic diversity and parameters of performance in the first year; however, from the summer of the second year onwards, genotypic diversity enhanced four of the six parameters of performance. After two growing seasons, there were significant positive relationships between genotypic diversity and maximum spread distance, patch size, shoot number per patch, and aboveground biomass. Moreover, abundance of the native dominant species Scirpus mariqueter was marginally significantly decreased with genotypic diversity of S. alterniflora, suggesting that enhanced invasive ability of S. alterniflora may have depressed the growth of the native species. There was no significant difference in most measures of performance among six genotypes, but we observed a transgressive over performance in four measures in multiple‐genotype patches. At the end of the experiment, there were significant nonadditive effects of genotypic diversity according to Monte Carlo permutations, in six‐genotype, but not three‐genotype plots. Our results indicated that both additive and nonadditive effects played roles in the positive relationship between genetic diversity and invasion success, and nonadditive effects were stronger as duration increased.     

霍乱弧菌EL－Tor35A3菌株外膜蛋白主区带的纯化

选用霍乱弧菌ＥＬ－Ｔｏｒ生物型３５Ａ３菌株（血清稻叶型）以ＥＤＴＡ－溶菌酶法与超速离心法提取其外膜蛋白,并将聚丙烯酰胺凝胶电泳后一条蛋白主区带分离。ＳＤＳ－聚丙烯酰胺凝胶电泳测得该蛋白主区带的分子量为２５ｋＤ,免疫电泳显示一条线,免疫双扩试验表明,不同的霍乱弧菌菌株均有该蛋白抗原存在。     

The auxin transporter,OsAUX1, is involved in primary root and root hair elongation and in Cd stress responses in rice (Oryza sativa L.)

Auxin and cadmium (Cd) stress play critical roles during root development. There are only a few reports on the mechanisms by which Cd stress influences auxin homeostasis and affects primary root (PR) and lateral root (LR) development, and almost nothing is known about how auxin and Cd interfere with root hair (RH) development. Here, we characterize rice osaux1 mutants that have a longer PR and shorter RHs in hydroponic culture, and that are more sensitive to Cd stress compared to wild‐type (Dongjin). OsAUX1 expression in root hair cells is different from that of its paralogous gene, AtAUX1, which is expressed in non‐hair cells. However, OsAUX1, like AtAUX1, localizes at the plasma membrane and appears to function as an auxin tranporter. Decreased auxin distribution and contents in the osaux1 mutant result in reduction of OsCyCB1;1 expression and shortened PRs, LRs and RHs under Cd stress, but may be rescued by treatment with the membrane‐permeable auxin 1‐naphthalene acetic acid. Treatment with the auxin transport inhibitors 1‐naphthoxyacetic acid and N‐1‐naphthylphthalamic acid increased the Cd sensitivity of WT rice. Cd contents in the osaux1 mutant were not altered, but reactive oxygen species‐mediated damage was enhanced, further increasing the sensitivity of the osaux1 mutant to Cd stress. Taken together, our results indicate that OsAUX1 plays an important role in root development and in responses to Cd stress.     

土壤活性有机碳的表征及其生态效应

土壤活性有机碳指在一定的时空条件下,受植物、微生物影响强烈、具有一定溶解性、在土壤中移动比较快、不稳定、易氧化、分解、易矿化,其形态,空间位置对植物、微生物来说活性比较高的那一部分土壤碳素。国外描述这一部分碳素的术语为有效碳、水溶性碳、易氧化碳、可矿...     

TNF-α-308G/A Polymorphism Contributes to Obstructive Sleep Apnea Syndrome Risk: Evidence Based on 10 Case-Control Studies

Objective

The aim of our study was to investigate the association between the TNF-α-308G/A polymorphism and obstructive sleep apnea syndrome (OSAS).

Method

The Medline, Web of Science, EMBASE, Chinese National Knowledge Infrastructure (CNKI), and Cochrane Central Register of Controlled Trials were searched. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to study TNF-α-308G/A polymorphism and risk of OSAS.

Result

10 case-control studies were included in our meta-analysis. The results from our study showed that the TNF-α-308G/A polymorphism was significantly associated with risk of OSAS (A vs. G: OR = 1.67, 95% CI = 1.43–1.95). In the subgroup analysis by ethnicity, the statistical similar results were observed both in European (A vs. G: OR = 1.68, 95% CI = 1.35–2.08) and Asian population (A vs. G: OR = 2.02, 95% CI = 1.50–2.71). When stratified by age, a significantly increased risk was observed in adult carries A allele compared with G allele (OR = 1.79, 95% CI = 1.50–2.13), whereas no association was found in children (OR = 1.09, 95% CI = 0.70–1.69).

Conclusion

Our study suggested that the TNF-α- 308G/A polymorphism contributed to the susceptibility to the risk of OSAS. Additional well-designed large studies are needed to validate our findings.     

Importance of FADD signaling in serum deprivation- and hypoxia-induced cardiomyocyte apoptosis

Although cardiomyocyte (CM) apoptosis has been well described in both in vitro and in vivo models of ischemic heart disease, the intracellular pathways leading to CM death have not been fully characterized. To define the role of death receptor signaling in CM apoptosis, we constructed recombinant adenoviral vectors carrying wild-type (wt) or dominant negative (dn) forms of the death receptor adaptor protein FADD (Fas-associated death domain protein) and used these vectors to transduce rat neonatal CMs in models of hypoxia- and serum deprivation (SD)-induced apoptosis. The combination of SD and hypoxia induced rapid activation of caspase-3 and -8 as well as DNA fragmentation, reaching a plateau within 4-8 h. Adenoviral expression of FADD-dn inhibited caspase-8 activation as well as hypoxia/SD-induced apoptosis at 24 h in an moi (multiplicity of infection)-dependent manner. In contrast, adenoviral expression of FADD-wt increased apoptosis and caspase-3 activity in CMs under both normoxic and hypoxic conditions. Surprisingly, FADD-dn, as well as the specific caspase-8 inhibitor benzyloxycarbonyl-IETD-fluoromethylketone also inhibited the activation of caspase-9 and -3 in CMs subjected to hypoxia/SD. These data suggest a primary role for FADD/caspase-8 signaling that is necessary and sufficient for apoptosis of CMs subjected to hypoxia/SD.