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971.
动粒是参与有丝分裂过程中染色体分离的蛋白的附着支架。结构保守的Ndc80复合体位于动粒的外层,连接动粒和微管,与动粒-微管连接的稳定性有关。Aurora B/Ipl1激酶参与纠正动粒-微管的错误连接。Ndc80复合体对纺锤体组装检查点的功能非常重要。本文主要介绍了Ndc80复合体的研究进展。 相似文献
972.
F. Li H. Chen C. Z. Lei G. Ren J. Wang Z. J. Li J. Q. Wang 《Molecular biology reports》2010,37(1):501-505
In this study, polymorphism in the exon 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11 of bovine NUCB2 gene was detected by PCR-SSCP and DNA sequencing methods in 686 individuals from three Chinese cattle breeds. Two haplotypes
(M and N), three observed genotypes (MM, MN and NN) and two SNPs (NC_007313: g. 27451G>A, NC_007313: g. 27472T>C) were detected. The frequencies of haplotypes M and N in inland
Chinese three breeds were 0.531–0.721 and 0.279–0.469 respectively. The studied showed that Nanyang, Jiaxian Red and Qinchuan
cattle populations were in Hardy–Weinberg equilibrium at SNPs locus of NUCB2 gene (P > 0.05). Polymorphism of the NUCB2 gene was shown to be associated with growth traits in Qingchuan and Nanyang cattle breed. The linkage of two mutant sites
in the bovine NUCB2 gene had significant effects on body length, body weight, heart girth, and average daily gain at 24 months (P < 0.05). Results of this study suggested that the NUCB2-gene-specific SNP may be a useful marker for growth traits in future marker-assisted selection programmes in inland Chinese
cattle. 相似文献
973.
Qun Zeng Huang 《Carbohydrate research》2010,345(1):115-119
A new supermolecular assembly crystal, [C6H8N2]6H3[PW12O40]·2H2O (DMB-PWA), was synthesized with phosphotungstic acid (PWA) and 1,2-diaminobenzene (DMB) under hydrothermal conditions and was characterized by Fourier-transform infrared spectra (FTIR) and single-crystal X-ray diffraction analysis. DMB-PWA could effectively catalyze oxidative degradation of chitosan with H2O2 in the heterogeneous phase. The optimum degradation conditions were determined by orthogonal tests as follows: amount of chitosan 1.00 g, 30% (wt %); H2O2, 3.0 mL; dosage of catalyst, 0.06 g; reaction temperature, 85 °C; and reaction time, 30 min. The water-soluble chitosan with a viscosity-average molecular weight (Mv) of 4900 was obtained under the optimum degradation conditions and was characterized by FTIR, ultraviolet-visible diffuse reflection spectra (UV-vis DRS), and X-ray powder diffraction analysis. 相似文献
974.
Yun-Sheng Zhang Xue-Yi Yang Xiao-Bin Wang Chun-Mei Zhang Fang Qin Zhen-Hui Zhou Xian-Yong Lan Hong Chen Chu-Zhao Lei 《Biochemical genetics》2010,48(7-8):636-646
To clarify the origin of Chinese domestic donkeys, we investigated the mitochondrial Cytb gene from 244 animals from 13 native breeds. We found 55 variable sites in the Cytb gene sequence and subsequently defined 58 haplotypes. Analysis of haplotypes in combination with Cytb sequences revealed two mitochondrial origins in Chinese domestic donkeys, phenotypically expressed by the Somalian and Nubian lineages. The Somalian lineage predominated in Chinese domestic donkey breeds. Five specific Cytb gene SNPs diagnostic of each of the lineages were found in this study: 225(T-C), 237(C-T), 915(C-T), 1014(C-T), and 1134(A-G) mutations. They effectively distinguish the Nubian from the Somalian lineage in the mtDNA Cytb gene. Both lineages are from Africa and thus support the African maternal origins of Chinese domestic donkeys. No obvious geographic structure was found in Chinese domestic donkey breeds, but the population showed abundant genetic diversity. 相似文献
975.
976.
977.
在不同条件下人工饲养大鲵的呼吸特征 总被引:1,自引:0,他引:1
于2004年4月25日~5月15日在河南卢氏县大鲵(Andrias davidianus)养殖场对大鲵肺呼吸活动的方式进行了详细观察,发现与已报道的方式不同。大鲵的肺呼吸采取了肺腔贮存气体、间歇式浮出水面、以1次呼气和2次吸气、咽气过程构成的换气方式来适应水栖生活,其肺呼吸活动方式属于四程式呼吸。大鲵在白天休息状态下的肺换气频次受气温、水温和大气压等气候因子变化的影响,换气频次的多少与水温的高低变化呈正相关(R=0.917,P〈0.01),与大气压的高低变化呈负相关(R=-0.954.P〈0.01)。 相似文献
978.
《Enzyme and microbial technology》2005,36(5-6):648-653
A recombinant insecticide-resistant mosquito carboxylesterase B1 was purified to homogeneity from an Escherichia coli expression system. After non-denaturing electrophoresis, active carboxylesterase B1 bands were identified using fast blue RR. Lineweaver–Burk plots of the crude and purified CaE B1 indicate that this enzyme obeys Michaelis–Menten kinetics with Km value for malathion of 39.3 and 67.4 mM. The Vm of purified enzyme is approximately 17-folds of the value determined in crude homogenate. Carboxylesterase B1 detoxification of parathion had a major limitation which is the 1:1 stoichiometry. To improve the effectiveness of enzymatic detoxification, we developed an approach in which the catalytic activity of organophosphorus compound-inhibited carboxylesterase B1 was restored by having sufficient amounts diacetylmonoxime. It was demonstrated that repeated addition of 25 times the molar concentration of parathion to carboxylesterase B1 in the presence of 4 mM diacetylmonoxime every 2 h did not result in significant inhibition of the enzyme. Consequently the stoichiometry of enzyme detoxification is higher than 64: 1 for parathion. 相似文献
979.
980.