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131.
利用人粒细胞集落刺激因子(hG-CSF)cDNA3′端非翻译区(3′-UTR)中存在的DraⅠ酶切位点,通过部分酶切与完全酶切,删除3′-UTR不同长度,构建了四种hG-CSFcDNA瞬时重组表达质粒。转染COS-7细胞后,生物活性测定结果提示,hG-CSFcDNA3′-UTR对其表达起负调控作用,其关键性序列位于紧接终止密码子TGA下游的65bp范围内,3′-UTR对hG-CSFcDNA表达的影响与转录水平的差别有一定关系。 相似文献
132.
大鼠大脑皮层中钙调神经磷酸酶活力的时空变化 总被引:1,自引:0,他引:1
以PNPP为底物测定了超离心制备的大鼠出生后早期和成年大脑皮层亚细胞各组分中钙调神经磷酸酶的活力。实验结果表明:(l)钙调神经磷酸酶活力广泛地存在于胞液和突触部分,并且各亚细胞组分有明显差异。成年大鼠大脑皮层中CaN活力相对最高水平是在突触体,突触质,胞液,重的和轻的突触膜部分。(2)大鼠大脑皮层突触体中CaN活力在出生后第2周和第3周出现高峰的平台期,这与突触发生的高峰期是一致的。在胞液和重的突触膜中CaN活力最高水平是在出生后的第7d,而在突触质和轻的突触膜中是在第20d。总之,这些发现证实,在脑发育期间,CaN活力是依照区域和时间性控制的,提示CaN可能参与了突触功能作用。 相似文献
133.
We describe a new immunoassay which combines an immunosorbent assay, Immunogold silver staining and epipolarization microscopy. Our new assay procedure features multiple samples on a single microscope slide, and high sensitivity of epipolarization microscope for detection of silver-enhanced colloidal gold as a final immunoassay product. We call the new immunoassay “on slide immunogold assay” (OSIGA). This new method uses biotinylated antibody and streptavidin-gold reaction with silver enhancement technique. With OSIGA it is possible to investigate 30 samples on a single microscopic slide. Our preliminary studies used 10-20 μ1 samples and detected nanogram quantities of a standardized protein solution. Unlike enzyme linked immunosorbent assay (ELISA), which has a limited time for reading the final color products, the OSIGA specimens can be dried or resin mounted for longer storage and future reference. 相似文献
134.
Deletion between direct repeats in T7 DNA stimulated by double-strand breaks. 总被引:6,自引:3,他引:3 下载免费PDF全文
An in vitro system based on extracts of Escherichia coli infected with bacteriophage T7 was used to study genetic deletions between directly repeated sequences. The frequency of deletion was highest under conditions in which the DNA was actively replicating. Deletion frequency increased markedly with the length of the direct repeat both in vitro and in vivo. When a T7 gene was interrupted by 93 bp of nonsense sequence flanked by 20-bp direct repeats, the region between the repeats was deleted in about 1 out of every 1,600 genomes during each round of replication. Very similar values were found for deletion frequency in vivo and in vitro. The deletion frequency was essentially unaffected by a recA mutation in the host. When a double-strand break was placed between the repeats, repair of this strand break was often accompanied by the deletion of the DNA between the direct repeats, suggesting that break rejoining could contribute to deletion during in vitro DNA replication. 相似文献
135.
136.
The objective of this study was to evaluate the growth and nutrient-uptake characteristics of Fe-deficiency resistant and susceptible subclover (Trifolium subterraneum L., T. yanninicum Katzn. and Morley, T. brachcalycinum Katzn. and Morley) cultivars on a calcareous soil. Ten subclover cultivars showing varying susceptibilities to Fe-deficiency chlorosis (Karridale, Nangeela, Geraldton, Mt. Barker, Woogenellup, Larisa, Trikkala, Rosedale, Koala and Clare) were grown on a low-Fe, calcareous soil (Petrocalcic Paleustoll) under moist (18% water content, 85% of water holding capacity) and water-saturated conditions using a Cone-tainer® culture system. Chlorosis and its correlation with growth traits and mineral nutrition of the 10 cultivars were examined. The Fe-deficiency susceptibilities of the 10 cultivars decreased in the above order under the moist condition, but in slightly different order under the saturated condition. Shoot and root dry weights, total dry weight, and root-to-shoot ratio were each negatively correlated with chlorosis under both soil-moisture conditions, as was total shoot content of P, Ca, Fe, Mn and Zn. Shoot P and Fe concentrations were each positively correlated with chlorosis under the moist soil condition. Iron and Cu utilization efficiencies (biomass per unit weight of nutrient) in the shoot were each negatively correlated with chlorosis under the moist soil condition. These results suggest that there may be several characteristics of Fe-deficiency chlorosis resistance in subclovers, such as a more effective soil-Fe mobilizing mechanism(s), more balanced nutrition, lower required Fe concentration in the shoot, higher shoot-Fe utilization efficiency, and higher root/shoot ratio under Fe-deficiency stress conditions. 相似文献
137.
Largepterosaurwithamaximumwingspanofmorethan5metres.Theskullislowerandlonger,withoutmiddlecrestorsupraoccipita1crest.ThenasaIandpre-orbita1fenestraareconfluentcompletely,andoccupyaboutha1foftheskulI1ength.Thetoothlessbeakisslenderandpointed.The1ongneckiscomposedbyse-venslendercervicalvertebrae.Thenotariumconsistsofsixco-ossifiedanteriordorsalvertebrae-ThetaiIisextremlyshort.lthassixpairsof"A"shapegastralia.Theanteriorlimbsarestrong;thehumerusarethickandshort;thewing-metacarpalbonearelongert… 相似文献
138.
139.
报道了测定CK-MM亚型的聚焦色谱法,此法简单,快速,结果可靠,线性范围宽,最低检测限(8U/L)较正常参考值低,比国外报道的类似方法高6倍以上,分离度亦有改进.测定了20例健康人血清亚型分布,与文献报道结果相近.该法自动化程度高,已在急性心梗的诊断中实际应用. 相似文献
140.
M. E. Hodes S. R. Dlouhy J. J. Wei Y. Wang L. Sangameswaran V. Lazar L. C. Triarhou B. Ghetti 《Neurochemical research》1994,19(11):1359-1362
The mouse autosomal recessive mutant gene weaver (wv) results in abnormalities in cerebellum, substantia nigra and testis. Although a subtracted cDNA library prepared by removing P31 (wv/wv) sequences from a P1 (wv/+) library should contain mainly nonrepetitive neonatal sequences, unfortunately, repetitive sequences still appear during screening. Two clones, one repetitive, the other not, are used to illustrate the problems encountered in attempting to isolate the weaver gene from a subtracted cDNA library.Special issue dedicated to Dr. Sidney Ochs. 相似文献