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黑龙江省东宁县山区蜱类的生态调查 总被引:2,自引:0,他引:2
我国东北地区有的蜱种已证实是传播森林脑炎、北亚蜱传斑疹伤寒的媒介。近年来,国内文献又报导了从东北牡丹江林区发现了莱姆病(Lyme Disease)病人,病人都有被婢咬史,并从全沟硬蜱(Ixodes persulcatus)的中 相似文献
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Dun X Zhou Z Xia S Wen J Yi B Shen J Ma C Tu J Fu T 《The Plant journal : for cell and molecular biology》2011,68(3):532-545
Here, we describe the characteristics of a Brassica napus male sterile mutant 7365A with loss of the BnMs3 gene, which exhibits abnormal enlargement of the tapetal cells during meiosis. Later in development, the absence of the BnMs3 gene in the mutant results in a loss of the secretory function of the tapetum, as suggested by abortive callose dissolution and retarded tapetal degradation. The BnaC.Tic40 gene (equivalent to BnMs3) was isolated by a map-based cloning approach and was confirmed by genetic complementation. Sequence analyses suggested that BnaC.Tic40 originated from BolC.Tic40 on the Brassica oleracea linkage group C9, whereas its allele Bnms3 was derived from BraA.Tic40 on the Brassica rapa linkage group A10. The BnaC.Tic40 gene is highly expressed in the tapetum and encodes a putative plastid inner envelope membrane translocon, Tic40, which is localized into the chloroplast. Transmission electron microscopy (TEM) and lipid staining analyses suggested that BnaC.Tic40 is a key factor in controlling lipid accumulation in the tapetal plastids. These data indicate that BnaC.Tic40 participates in specific protein translocation across the inner envelope membrane in the tapetal plastid, which is required for tapetal development and function. 相似文献
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Evolution of gp85 gene of subgroup J avian leukosis virus under the selective pressure of antibodies
Subgroup J Avian leucosis virus (ALV-J) strain NX0101 was inoculated into chicken embryo fibroblasts (CEF) monolayers in 6-well
plates. The six wells of CEF inoculated with NX0101 were divided into groups A (without anti-ALV-J serum in the medium) and
B (with anti-ALV-J serum in the medium), then viruses from each well of both groups were separately passed in CEF every 6
d and formed their independent passage lineages. For each lineage of both groups, gp85 genes of the viruses in the 10th, 20th
and 30th passages were amplified, cloned and sequenced. The sequence data indicated that the homologies of gp85 at aa level
between the primary virus and the passed viruses of different passages of 3 lineages in group A were 97.7%–99.7%; and the
homologies of gp85 between the primary virus and the passed viruses of different passages of 3 lineages in group B were 93.8%–96.1%.
Analysis of the ratios of nonsynonium (NS) vs synonium (S) mutations of nucleic acids demonstrated that NS/S in 3 highly variable
(hr-) regions at aa#110–120, aa#141–151 and aa#189–194 of gp85 in 3 lineages of group A were 2 (8/4), 1(3/3) and 1.3 (4/3),
however, NS/S in the same 3 hr-regions of group B were 4.1 (13/3), 4.7 (14/3) and 3.3 (11/3). This study is the first demonstration
of influence of immune selective pressure on evolution of ALV-J gp85 by specific antibodies under the controlled in vitro experiments. 相似文献
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Li S Yan Y Zhou Z Yu H Zhan Y Zhang W Chen M Lu W Ping S Lin M 《Molecular biology reports》2011,38(4):2437-2443
The −1 subsite of bacterial fructansucrases (FSs) (levansucrases and inulosucrases) plays an important role in the substrate
recognition, binding and catalysis. Three residues (for example W47, W118 and R193, Zymomonas mobilis levansucrase numbering) at the −1 subsite are completely conserved among FSs. Site-directed mutational analysis showed that
the substitutions of the three strictly conserved amino acid residues, W47N, W47H, W118N, W118H, R193K and R193H, significantly
decreased enzyme activities and synthesis rates of levan, while the size of the synthesized oligosaccharides had been influenced.
These experimental results, combined with 3D structure modeling, lead to our proposal that a single amino acid residue change
in subsite −1 of levansucrase can influence change to the size and polarity of the sucrose binding pocket with a concomitant
change to substrate binding and catalysis, and thus having an overall influence on the enzyme activities and products. 相似文献
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西部干旱区煤炭开采环境影响研究 总被引:24,自引:4,他引:20
大规模煤炭资源开采与干旱脆弱生态环境的空间耦合将会诱发日益严峻的社会、环境问题。分析了我国西部干旱区煤炭地下开采对植被、土壤水、地下水、土壤等关键环境要素影响的研究进展与不足;指出现有研究主要以单一环境要素、局部尺度为主,缺乏多尺度综合的环境要素协同损伤规律与井上下联动响应机理等基础研究。因此,现有成果还无法满足指导煤炭开采技术改进与控制环境损伤的需要。建议从井下到井上,从工作面、矿井、矿区、流域多尺度综合实现地空一体化同步监测,加强对西部干旱矿区各关键环境要素的协同损伤规律研究;加强对井上下环境要素对开采地质条件响应机理研究;建立不同开采条件、不同评价尺度下,矿区开采环境损伤的评价与预测模型。 相似文献
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