排序方式: 共有12条查询结果,搜索用时 171 毫秒
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Imprinted microRNA genes transcribed antisense to a reciprocally imprinted retrotransposon-like gene 总被引:18,自引:0,他引:18
Seitz H Youngson N Lin SP Dalbert S Paulsen M Bachellerie JP Ferguson-Smith AC Cavaillé J 《Nature genetics》2003,34(3):261-262
MicroRNAs (miRNAs) are an abundant class of RNAs that are approximately 21-25 nucleotides (nt) long, interact with mRNAs and trigger either translation repression or RNA cleavage (RNA interference, RNAi) depending on the degree of complementarity with their targets. Here we show that the imprinted mouse distal chromosome 12 locus encodes two miRNA genes expressed from the maternally inherited chromosome and antisense to a retrotransposon-like gene (Rtl1) expressed only from the paternal allele. 相似文献
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The T/t-complex of the mouse includes a series of recessive lethal and semi-lethal mutations but, despite such lethalities, mutant t-haplotypes are found in high frequency in wild mouse populations. This polymorphism is apparently maintained because heterozygous males preferentially transmit the t-bearing chromosome to their offspring. Despite many attempts to define the basis of the transmission ratio distortion, it has been unclear whether this is because t-bearing sperm have better than average fertilizing ability or whether +-bearing sperm in heterozygous males are rendered defective. To examine this point, we constructed male (XY in equilibrium XY) chimaeras containing +/+ and +/tw73 genotypes, marked respectively by albino and pigmented coat colours, and two isozyme variants. Such males produce a mixture of three different sperm types: +-bearing sperm from the +/+ genotype, +-bearing sperm from the +/t genotype, and t-bearing sperm from the +/t genotype. Appropriate matings can distinguish between these three types, and our data, reported here, show that t-bearing sperm in chimaeric mice maintain their advantage over their 'meiotic partners' but do not have any advantage over sperm from the +/+ genotype. 相似文献
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Suppression of Raf-1 kinase activity and MAP kinase signalling by RKIP. 总被引:39,自引:0,他引:39
K Yeung T Seitz S Li P Janosch B McFerran C Kaiser F Fee K D Katsanakis D W Rose H Mischak J M Sedivy W Kolch 《Nature》1999,401(6749):173-177
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本通过对几种拆分手性药物的方法的列举,比较几种方法,详细介绍了几种方法的特点,以及它们的不同作用。各个方法中又列出了不同的线索,根据这些线索来研究这几种拆分的方法,它们的优缺点以及针对这些缺点的解决方法,最后给出了几个典型的用该方法的实验,以辨别它们的效用。 相似文献
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Intestinal degradation and absorption of the glycosidic sweeteners stevioside and rebaudioside A 总被引:2,自引:0,他引:2
R. E. Wingard Jr J. P. Brown F. E. Enderlin J. A. Dale R. L. Hale C. T. Seitz 《Cellular and molecular life sciences : CMLS》1980,36(5):519-520
Summary Contrary to prior indications, the glycosidic sweeteners stevioside and rebaudioside A are degraded to the diterpenoid aglycone steviol by rat intestinal microflora in vitro. Additional studies with steviol-17-[14C] show almost total absorption from the rat lower bowel following intracecal administration.A preliminary report of this work was presented at the annual meeting of the Federated American Societies for Experimental Biology, Dallas 1979. We thank G.A. Crosby, T.M. Parkinson and N.M. Weinshenker for helpful suggestions, and B.C. Hyde for technical assistance. 相似文献
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Linxia Zhang Linsey C. Seitz Amy M. Abramczyk Li Liu Christina Chan 《Cellular and molecular life sciences : CMLS》2011,68(5):863-876
The intracellular second messenger cAMP is frequently used in induction media to induce mesenchymal stem cells (MSCs) into
neural lineage cells. To date, an understanding of the role cAMP exerts on MSCs and whether cAMP can induce MSCs into functional
neurons is still lacking. We found cAMP initiated neuron-like morphology changes early and neural differentiation much later.
The early phase changes in morphology were due to cell shrinkage, which subsequently rendered some cells apoptotic. While
the morphology changes occurred prior to the expression of neural markers, it is not required for neural marker expression
and the two processes are differentially regulated downstream of cAMP-activated protein kinase A. cAMP enabled MSCs to gain
neural marker expressions with neuronal function, such as, calcium rise in response to neuronal activators, dopamine, glutamate,
and potassium chloride. However, only some of the cells induced by cAMP responded to the three neuronal activators and further
lack the neuronal morphology, suggesting that although cAMP is able to direct MSCs towards neural differentiation, they do
not achieve terminal differentiation. 相似文献
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