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991.
We report on the isolation and characterization of nine microsatellite markers in the takin (Budorcas taxicolor) from genomic DNA-enriched libraries. Twenty-eight microsatellites were screened from the libraries, and nine of the screened
microsatellites were polymorphic. The number of observed alleles for each locus in 28 individuals ranged from two to seven,
and the expected and observed heterozygosity was 0.105–0.758 and 0.071–0.821, respectively. Four loci (TK01, TK02, TK04 and
TK08) of nine deviated from Hardy-Weinberg expectation and no significant linkage association was found among all these loci.
These microsatellite markers provide useful tool for population genetic studies of the takin. 相似文献
992.
Han HJ Tan NH Zeng GZ Fan JT Huang HQ Ji CJ Jia RR Zhao QS Zhang YJ Hao XJ Wang LQ 《化学与生物多样性》2008,5(7):1364-1368
DNA Topoisomerase I can cause DNA breaks and play a key role during cell proliferation and differentiation. It is an important target for anticancer agents. While screening for anticancer compounds, seven natural compounds, 1-7, showed potent cytotoxicities against a panel of ten cancer cell lines. Moreover, an inhibition assay demonstrated that they are also DNA topoisomerase I inhibitors, in which inhibitors 1-5 are new ones. 相似文献
993.
Hilterhaus L Minow B Müller J Berheide M Quitmann H Katzer M Thum O Antranikian G Zeng AP Liese A 《Bioprocess and biosystems engineering》2008,31(3):163-171
The immobilization of an endoglucanase, benzoylformate decarboxylase (BFD) from Pseudomonas putida, as well as of lipase B from Candida antarctica (CALB) onto the carrier supports Sepabeads EC-EP, Sepabeads EC-EA, and Sepabeads EC-BU was accomplished. It is shown that
via these immobilized biocatalysts the synthesis of both fine and bulk chemicals is possible. This is illustrated by the syntheses
of polyglycerol esters and (S)-hydroxy phenyl propanone. The benefit of immobilization is illustrated by repetitive use in a bubble column reactor as well
as in a stirred tank reactor. High stability of two biocatalysts was achieved and reusability up to eight times was demonstrated.
The comparison of CALB immobilized on Sepabeads EC-EP to Novozym 435 shows similar activity.
Dedicated to Prof. Dr. Christian Wandrey on the occasion of his 65th birthday. 相似文献
994.
Shuyang Xie Wei Li Zhaorui Ren Jingzhi Zhang Xinbin Guo Shu Wang Shuzhen Huang Fanyi Zeng Yi-Tao Zeng 《遗传学报》2008,35(10)
Large amounts of aberrantly spliced mRNA from the β654 allele was present in erythroid cells, which might impair the erythropoiesis.A therapeutic strategy for β-thalassemia was explored by knocking down the aberrantly spliced mRNA of β-globin. Lentiviral vector with siRNA fragment targets on the specific portion of β654-globin aberrantly spliced pre-mRNA was constructed. In HeLa β654 cells, the siRNA vector could reduce approximately 60% of aberrantly spliced mRNA, which was assessed by RT-PCR and qRT-PCR. Furthermore, a disease model of β654 thalassemia mice with lentiviral-mediated siRNA was produced by subzonal injection (named Hβi-Hbbth-4/Hbb+transgenic mice). Our results showed that the hemotological parameters were improved in Hβi-Hbbth-4/Hbb+ transgenic mice. This study provides a potential way for β654-thalassemia therapy by knocking down the aberrantly spliced β-globin mRNA, whilst supporting that the aberrantly spliced β-globin mRNA may aggravate the disease. 相似文献
995.
996.
Characterization of eight polymorphic microsatellite loci for the giant grouper (Epinephelus lanceolatus Bloch) 总被引:1,自引:0,他引:1
Eight polymorphic microsatellite loci were isolated and characterized using a small insert genomic DNA library for the giant grouper (Epinephelus lanceolatus Bloch, 1790), a commercially valuable marine fish in tropical waters. They showed polymorphism information content ranging from 0.177 to 0.775, allele numbers ranging from two to 10, effective allele numbers ranging from 1.227 to 5.012, and observed and expected heterozygosities from 0.2 to 0.733 and from 0.185 to 0.801, respectively, which we anticipate will be useful for population genetic studies of the giant grouper. 相似文献
997.
A growing body of evidence suggests an important role for fibrinogen-like proteins in innate immunity in both vertebrates and invertebrates. It has been shown that fibrinogen-related proteins (FREPs), plasma proteins present in the freshwater snail Biomphalaria glabrata, the intermediate host for the human blood fluke Schistosoma mansoni, are diverse and involved in snail innate defense responses. To gain further insight into the functions of FREPs, recombinant FREP proteins (rFREPs) were produced in Escherichia coli and antibodies (Abs) were raised against the corresponding rFREPs. We first show that most FREP proteins exist in their native conformation in snail hemolymph as multimeric proteins. Western blot analyses reveal that expression of multiple FREPs including FREP4 in plasma from M line and BS-90 snails, which are susceptible and resistant to S. mansoni infection, respectively, is up-regulated significantly after infection with the trematode Echinostoma paraensei. Moreover, our assays demonstrate that FREPs are able to bind E. paraensei sporocysts and their secretory/excretory products (SEPs), and a variety of microbes (Gram-positive and Gram-negative bacteria and yeast). Furthermore, this binding capability shows evidence of specificity with respect to pathogen type; for example, 65-75-kDa FREPs (mainly FREP4) bind to E. paraensei sporocysts and their SEPs whereas 95-kDa and 125-kDa FREPs bind the microbes assayed. Our results suggest that FREPs can recognize a wide range of pathogens, from prokaryotes to eukaryotes, and different categories of FREPs seem to exhibit functional specialization with respect to the pathogen encountered. 相似文献
998.
Ya-li Li Guang-zhi Wu Gavin S. Dawe Li Zeng Shu-sen Cui Gabriele Loers Thomas Tilling Li Sun Melitta Schachner Zhi-Cheng Xiao 《PloS one》2008,3(12)
Background
Cell surface glycosylation patterns are markers of cell type and status. However, the mechanisms regulating surface glycosylation patterns remain unknown.Methodology/Principal Findings
Using a panel of carbohydrate surface markers, we have shown that cell surface sialylation and fucosylation were downregulated in L1−/y neurons versus L1+/y neurons. Consistently, mRNA levels of sialyltransferase ST6Gal1, and fucosyltransferase FUT9 were significantly reduced in L1−/y neurons. Moreover, treatment of L1+/y neurons with L1 antibodies, triggering signal transduction downstream of L1, led to an increase in cell surface sialylation and fucosylation compared to rat IgG-treated cells. ShRNAs for both ST6Gal1 and FUT9 blocked L1 antibody-mediated enhancement of neurite outgrowth, cell survival and migration. A phospholipase Cγ (PLCγ) inhibitor and shRNA, as well as an Erk inhibitor, reduced ST6Gal1 and FUT9 mRNA levels and inhibited effects of L1 on neurite outgrowth and cell survival.Conclusions
Neuronal surface sialylation and fucosylation are regulated via PLCγ by L1, modulating neurite outgrowth, cell survival and migration. 相似文献999.
Cobalt is an essential microelements in many biological processes involving enzymatic activity. We found that Zn2+ and Mg2+, which are in the active site of native calf intestine alkaline phosphatase (CIP), can be replaced by Co2+ directly in solution. The effect of Co2+ concentration on the substitution reaction was examined at ratios of [Co2+]/[CIP] from 0:1 to 8:1. The quantity of Zn2+ in CIP decreased progressively as the ratio was increased, but the amount of Mg2+ changed in irrregular fashion. A series of active site models of the reaction mechanism of CIP are proposed. Low pH was found to promote the replacement of Mg2+ by Co2+. To understand how the substitution affects the enzyme, we also solved the secondary structure of CIP after reaction with Co2+ in different conditions. 相似文献
1000.
Zhang Y Ju J Peng H Gao F Zhou C Zeng Y Xue Y Li Y Henrissat B Gao GF Ma Y 《The Journal of biological chemistry》2008,283(46):31551-31558
An intracellular mannanase was identified from the thermoacidophile Alicyclobacillus acidocaldarius Tc-12-31. This enzyme is particularly interesting, because it shows no significant sequence similarity to any known glycoside hydrolase. Gene cloning, biochemical characterization, and structural studies of this novel mannanase are reported in this paper. The gene consists of 963 bp and encodes a 320-amino acid protein, AaManA. Based on its substrate specificity and product profile, AaManA is classified as an endo-beta-1,4-mannanase that is capable of transglycosylation. Kinetic analysis studies revealed that the enzyme required at least five subsites for efficient hydrolysis. The crystal structure at 1.9 angstroms resolution showed that AaManA adopted a (beta/alpha)8-barrel fold. Two catalytic residues were identified: Glu151 at the C terminus of beta-stand beta4 and Glu231 at the C terminus of beta7. Based on the structure of the enzyme and evidence of its transglycosylation activity, AaManA is placed in clan GH-A. Superpositioning of its structure with that of other clan GH-A enzymes revealed that six of the eight GH-A key residues were functionally conserved in AaManA, with the exceptions being residues Thr95 and Cys150. We propose a model of substrate binding in AaManA in which Glu282 interacts with the axial OH-C(2) in-2 subsites. Based on sequence comparisons, the enzyme was assigned to a new glycoside hydrolase family (GH113) that belongs to clan GH-A. 相似文献