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1.
Yixin Zheng Xuejie Fu Qingbai Liu Shengqi Guan Cunchang Liu Chunmei Xiu Tingting Gong Hongting Jin Saijilafu Zunyi Zhang Di Chen Jianquan Chen 《Journal of cellular physiology》2019,234(9):14422-14431
Cre/loxP technology is an important tool for studying cell type-specific gene functions. Cre recombinase mouse lines, including Agc1-CreERT2, Col2a1-Cre; Col2a1-CreERT2, Shh-Cre, Shh-CreERT2, and Osx-Cre, have been proven to be valuable tools to elucidate the biology of long bones, yet the information for their activity in postnatal intervertebral disc (IVD) tissues was very limited. In this study, we used R26-mTmG fluorescent reporter to systematically analyze cell specificity and targeting efficiency of these six mouse lines in IVD tissues at postnatal growing and adult stages. We found that Agc1-CreERT2 is effective to direct recombination in all components of IVDs, including annulus fibrosus (AF), nucleus pulposus (NP), and cartilaginous endplate (CEP), upon tamoxifen induction at either 2 weeks or 2 months of ages. Moreover, Col2a1-Cre targets most of the cells in IVDs, except for some cells in the outer AF (OAF) and NP. In contrast, the activity of Col2a1-CreERT2 is mainly limited to the IAF of IVD tissues at either stage of tamoxifen injection. Similarly, Shh-Cre directs recombination specifically in all NP cells, whereas Shh-CreERT2 is active only in a few NP cells when tamoxifen is administered at either stage. Finally, Osx-Cre targets cells in the CEP, but not in the NP or AF of IVDs tissues at these two stages. Thus, our data demonstrated that all these Cre lines can direct recombination in IVD tissues at postnatal stages with different cell type specificity and/or targeting efficiency, and can, therefore, serve as valuable tools to dissect cell type-specific gene functions in IVD development and homeostasis. 相似文献
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M.C. Matos A.A. Matos A. Mantas V. Cordeiro J.B. Vieira Da Silva 《Photosynthetica》1997,34(2):249-256
Five cultivars of Prunus amygdalus Batsch (Ferragnes, Ferrastar, Marcona, Garrigues, and Non Pareil) grafted on two different
rootstocks (Garrigues and GF677), and two cultivars (Ferraduel and Casa Nova) grafted on GF677, were grown for three years
under rainfed conditions in an orchard in northeast Portugal. Net photosynthetic rate (PN), leaf conductance for water vapour
(gs), leaf water potential (Ψ), instantaneous water use efficiency (WUE), and internal CO2 concentration (Ci) were measured
at three periods of the growing season: spring, summer (June or July) and late summer (September) over two years. Ferraduel,
Ferrastar, and Marcona presented the best performance in the periods when environmental conditions were not very hard (May
or September). Casa Nova and Non Pareil were well adapted to high air evaporative demand, preventing the increase of leaf
temperature (T1). Ferrastar, although having a good performance in May and September, did well adapt to hard climatic conditions
in June 1994. In the following year, although it presented the highest T1, the values were not limiting (30.6 ± 2.1 °C), and
PN was only decreased from May to July. Marcona was highly dependent on T1, but prevented its increasing. Garrigues showed
lower PN in most measurement periods. GF677 frequently induced the highest PN, WUE, and Ψ. PN was mainly dependent on T1,
radiation, Ci, month, and year. WUE depended on the same factors. Ψ depended mainly on gs, air temperature, month, and year.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Evidence for protein-tyrosine-phosphatase catalysis proceeding via a cysteine-phosphate intermediate. 总被引:33,自引:0,他引:33
A recombinant protein-tyrosine-phosphatase has been expressed in Escherichia coli and purified to a single band by sodium dodecyl sulfate-polyacrylamide gel electrophoresis using affinity chromatography. When the phosphatase was allowed to react with 32P-labeled substrates and then rapidly denaturated, a 32P-labeled phosphoprotein could be visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Transient formation of a 32P-labeled phosphoprotein was observed, and the 32P-labeled protein disappeared as substrate was consumed. In the presence of 32P-labeled p-nitrophenyl phosphate, 0.27 mol of phosphate was incorporated per mol of protein-tyrosine-phosphatase. Site-directed mutagenesis of a catalytically essential cystine residue (position 215) in the recombinant protein resulted in an inactive enzyme, and no phosphoprotein was formed. The 32P-labeled phosphoprotein showed a maximum lability between pH 2.5 and 3.5 and was rapidly decomposed in the presence of iodine. These properties, along with additional site-directed mutations, suggest that the protein-tyrosine-phosphatase forms a covalent thiol phosphate linkage between Cys215 and phosphate. 相似文献
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Hydrobiologia - Lake Malaŵi cichlids have evolved rapidly, extensively, and in some cases iteratively to fill an array of ecological niches; however, neither species richness nor trophic... 相似文献
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ZHENG LianBin LI YongLan XI HuanJiu YU KeLi LU ShunHua SHI Rui WEN YouFeng BAO JingPing ZHANG XingHua LI YuLing REN Fu XU GuoChang 《中国科学:生命科学英文版》2015,58(2):215-217,1,3
<正>Dear Editor,Shortly after initiating the"Physical Anthropological Research on Han Chinese"research project,we applied uniform sampling methods as well as methods and instruments of measurement to obtain a complete set of measurements of physical anthropological indicators among Han populations across China.Among these measurements,body stature was a key indicator.Currently,there should be reliable 相似文献
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