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1.
Allozyme electrophoresis of four sibling parthenogenetic Caucasian rock lizards Darevskia unisexualis, D.uzzelli, D.sapphirina, and D.bendimahiensis found seven clones and five variable loci. The data supported the hypothesis that D.raddei and D.valentini are the parental species of all four parthenogens. Variation patterns in Darevskia were summarized. Species that originated from a single F1 typically consisted of one widespread clone with a few rare clones. Species with multiple origins displayed variation only
slightly higher than species with a single origin. This is contrary to other genera of parthenogenetic lizards, in which cases
massive clonal variations were observed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
2.
3.
A biochemical investigation of arabinogalactan proteins (AGPs) in Physcomitrella
patens was undertaken with particular emphasis on the glycan chains. Following homogenization and differential centrifugation of
moss gametophytes, AGPs were obtained by Yariv phenylglycoside-induced precipitation from the soluble, microsomal membrane,
and cell wall fractions. Crossed-electrophoresis indicated that each of these three AGP fractions was a mixture of several
AGPs. The soluble AGP fraction was selected for further separation by anion-exchange and gel-permeation chromatography. The
latter indicated molecular masses of ∼100 and 224 kDa for the two major soluble AGP subfractions. The AGPs in both of these
subfractions contained the abundant (1,3,6)-linked galactopyranosyl residues, terminal arabinofuranosyl residues, and (1,4)-linked
glucuronopyranosyl residues that are typical of many angiosperm AGPs. Unexpectedly, however, the moss AGP glycan chains contained
about 15 mol% terminal 3-O-methyl-l-rhamnosyl residues, which have not been found in angiosperm AGPs. This unusual and relatively nonpolar sugar, also called
l-acofriose, is likely to have considerable effects on the overall polarity of Physcomitrella AGPs. A review of the literature indicates that the capacity to synthesize polymers containing 3-O-methyl-l-rhamnosyl residues is present in a variety of bacteria, algae and lower land plants but became less common through evolution
to the extent that this sugar has been found in only a few species of angiosperms where it occurs as a single residue on steroidal
glycosides. 相似文献
4.
Constitutive expression of human angiostatin in <Emphasis Type="Italic">Pichia pastoris</Emphasis> by high-density cell culture 总被引:1,自引:0,他引:1
Zhang AL Zhang TY Luo JX Chen SC Guan WJ Fu CY Peng SQ Li HL 《Journal of industrial microbiology & biotechnology》2007,34(2):117-122
A high-density cell culture method to produce human angiostatin has been successfully established by constitutive expression
of the protein in Pichia pastoris. The fermentation was carried out in a 20 l bioreactor with a 10 l working volume, using a high-density cell culture method
by continuously feeding with 50% glycerol−0.8% PTM4 to the growing culture for 60 h at 30°C. Dissolved oxygen level was maintained
at 25–30% and pH was controlled at 5 by the addition of 7 M NH4OH. Angiostatin was constitutively expressed during the fermentation by linking its expression to the P. pastoris constitutive GAP promoter (pGAP). But after 36 h of fermentation, the peak biomass growth was 305 as measured by absorption
of 600 nm, while the peak angiostatin expression was 176 mg/l. Similar to the product expressed from inducible system [24], angiostatin produced from constitutive system also inhibited the angiogenesis on the CAM and suppressed the growth of B16
melanoma in C57BL/6J mouse. The above results suggest that GAP promoter is more efficient than AOX1 promoter for the expression
of angiostatin in P. pastoris by shake flask culture or high-density cell fermentation and is likely to be an alternative to AOX1 promoter in large-scale
expression of angiostatin and other heterologous proteins.
Supported by the Natural Science Foundation of China (39670013) and “225” Science and Technology Program of Guangzhou Municipal
Government of China (99-Z-004-001). 相似文献
5.
Effect of post-harvest heat treatment on proteome change of peach fruit during ripening 总被引:1,自引:0,他引:1
The extracted proteins from the heat-treated peach fruit (dipped in hot water at 48°C for 10min and then stored at room temperature (20°C-25°C) for up to 6 days) were used for proteomic analysis in order to understand the response of post-harvest peach fruit to heat treatment during ripening stage at proteomic level. After two dimensional gels electrophoresis (2-DE) was conducted, more than 600 protein spots were detected. Among them, 35 differently expressed spots (P<0.05) were selected to be excised and analyzed using MALDI-TOF/TOF, and finally 30 protein spots were confidently identified according to NCBI database. The results demonstrated that among the thirty protein spots expressed particularly induced by heat treatment, 43% were related to stress response, 17% to cell structure, 13% to protein fate, 7% to glycolytic pathway, 3% to ripening and senescence and 17% to unclassified. All of them are involved in the regulation of peach fruit development and ripening. All these indicated that the self-defense capability of peach fruit was improved by heat treatment. The study will enable future detailed investigation of gene expression and function linked with peach fruit ripening. 相似文献
6.
Xiaoyu Zhang Hailang Tong Zhiqiang Han Long Huang Jing Tian Zhixing Fu Yunyi Wu Ting Wang Deyi Yuan 《Physiology and Molecular Biology of Plants》2021,27(5):959
Camellia oleifera is believed to exhibit a complex intraspecific polyploidy phenomenon. Abnormal microsporogenesis can promote the formation of unreduced gametes in plants and lead to sexual polyploidy, so it is hypothesized that improper meiosis probably results in the formation of natural polyploidy in Camellia oleifera. In this study, based on the cytological observation of meiosis in pollen mother cells (PMCs), we found natural 2n pollen for the first time in Camellia oleifera, which may lead to the formation of natural polyploids by sexual polyploidization. Additionally, abnormal cytological behaviour during meiosis, including univalent chromosomes, extraequatorial chromosomes, early segregation, laggard chromosomes, chromosome stickiness, asynchronous meiosis and deviant cytokinesis (monad, dyads, triads), was observed, which could be the cause of 2n pollen formation. Moreover, we confirmed a relationship among the length–width ratio of flower buds, stylet length and microsporogenesis. This result suggested that we can immediately determine the microsporogenesis stages by phenotypic characteristics, which may be applicable to breeding advanced germplasm in Camellia oleifera.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-01002-5. 相似文献
7.
8.
Zhang XY Liang J Chen da C Xiu MH He J Cheng W Wu Z Yang FD Haile CN Sun H Lu L Kosten TA Kosten TR 《PloS one》2012,7(2):e30937
The high prevalence of smoking in schizophrenia of European background may be related to smoking's reducing clinical symptoms and medication side effects. Because smoking prevalence and its associations with clinical phenotypes are less well characterized in Chinese than European patients with schizophrenia, we assessed these smoking behaviors using clinician-administered questionnaires and the Fagerstrom Test for Nicotine Dependence (FTND) in 776 Chinese male schizophrenia and 560 control subjects. Patients also were rated on the Positive and Negative Symptom Scale (PANSS), the Simpson and Angus Extrapyramidal Symptom Rating Scale (SAES), and the Abnormal Involuntary Movement Scale (AIMS). We found that the schizophrenia patients had a higher lifetime incidence of smoking (79% vs 63%), were more likely to be heavy smokers (61% vs 31%), and had lower smoking cessation rates (4% vs 9%) (all p<0.0001) than controls. Among the schizophrenia patients smoking prevalence increased with age, with the largest difference from controls in the age cohort of 55-75 years: 75% vs 46% (p<0.0001). Among the schizophrenia smokers 73% started to smoke before the onset of their illness by an average of 7.6 years. The patients with schizophrenia who were current smokers scored significantly lower on the PANSS negative symptom subscore (p<0.005), and on the SAES symptom scale (p<0.04; Bonferroni corrected p>0.05) than the non-smoking patients. These results suggest that Chinese males with schizophrenia smoke more frequently than the general population. Further, smokers with schizophrenia may display fewer negative symptoms and possibly less parkinsonism than non-smokers with schizophrenia. 相似文献
9.
Qing Xia Zi-Xian Chen Yi-Chao Wang Yu-Shui Ma Feng Zhang Wu Che Da Fu Xiao-Feng Wang 《PloS one》2012,7(11)
Background
Melatonin receptor 1B (MTNR1B) belongs to the seven-transmembrane G protein-coupled receptor superfamily involved in insulin secretion, which has attracted considerable attention as a candidate gene for type 2 diabetes (T2D) since it was first identified as a loci associated with fasting plasma glucose level through genome wide association approach. The relationship between MTNR1B and T2D has been reported in various ethnic groups. The aim of this study was to consolidate and summarize published data on the potential of MTNR1B polymorphisms in T2D risk prediction.Methods
PubMed, EMBASE, ISI web of science and the CNKI databases were systematically searched to identify relevant studies. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Heterogeneity and publication bias were also tested.Results
A total of 23 studies involving 172,963 subjects for two common polymorphisms (rs10830963, rs1387153) on MTNR1B were included. An overall random effects per-allele OR of 1.05 (95% CI: 1.02–1.08; P<10−4) and 1.04 (95% CI: 0.98–1.10; P = 0.20) were found for the two variants respectively. Similar results were also observed using dominant or recessive genetic model. There was strong evidence of heterogeneity, which largely disappeared after stratification by ethnicity. Significant results were found in Caucasians when stratified by ethnicity; while no significant associations were observed in East Asians and South Asians. Besides, we found that the rs10830963 polymorphism is a risk factor associated with increased impaired glucose regulation susceptibility.Conclusions
This meta-analysis demonstrated that the rs10830963 polymorphism is a risk factor for developing impaired glucose regulation and T2D. 相似文献10.
Feifei Chen Jianren Ye Wanhui Liu Chonlong Chio Wendy Wang Wensheng Qin 《Molecular Plant Pathology》2021,22(7):843-857
Genetic transformation is a valuable and essential method that provides powerful insights into the gene function of microorganisms and contributes to the construction of engineered bacteria. Here, we developed a novel genetic transformation system to easily knock out a highly GC-rich gene (74.71% GC) from Burkholderia pyrrocinia JK-SH007, a biocontrol strain of poplar canker disease. This system revealed a reliable selectable marker (trimethoprim resistance gene, Tmp) and a simplified, efficient transformation method (6,363.64 CFU/μg, pHKT2) that was developed via freeze-thawing. The knockout recombineering of B. pyrrocinia JK-SH007 was achieved through a suicide plasmid with a three-fragment mutagenesis construct. The three-fragment cassette for mutagenesis was generated by overlap extension and touchdown PCRs and composed of Tmp flanked by GC-rich upstream and downstream fragments from B. pyrrocinia JK-SH007. The mutant strain (ΔBpEG), which was verified by PCR, lost 93.3% of its ability to degrade carboxymethyl cellulose over 40 days. Overall, this system may contribute to future research on B. pyrrocinia traits. 相似文献