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101.
Sanjay Kumar Bharti Irfan Khan Taraswi Banerjee Joshua A. Sommers Yuliang Wu Robert M. Brosh Jr. 《Cellular and molecular life sciences : CMLS》2014,71(14):2625-2639
In 2010, a new recessive cohesinopathy disorder, designated Warsaw breakage syndrome (WABS), was described. The individual with WABS displayed microcephaly, pre- and postnatal growth retardation, and abnormal skin pigmentation. Cytogenetic analysis revealed mitomycin C (MMC)-induced chromosomal breakage; however, an additional sister chromatid cohesion defect was also observed. WABS is genetically linked to bi-allelic mutations in the ChlR1/DDX11 gene which encodes a protein of the conserved family of Iron–Sulfur (Fe–S) cluster DNA helicases. Mutations in the budding yeast ortholog of ChlR1, known as Chl1, were known to cause sister chromatid cohesion defects, indicating a conserved function of the gene. In 2012, three affected siblings were identified with similar symptoms to the original WABS case, and found to have a homozygous mutation in the conserved Fe–S domain of ChlR1, confirming the genetic linkage. Significantly, the clinically relevant mutations perturbed ChlR1 DNA unwinding activity. In addition to its genetic importance in human disease, ChlR1 is implicated in papillomavirus genome maintenance and cancer. Although its precise functions in genome homeostasis are still not well understood, ongoing molecular studies of ChlR1 suggest the helicase plays a critically important role in cellular replication and/or DNA repair. 相似文献
102.
The Prausnitz-Küstner (P-K) reaction is a sensitive test for the presence and activity in the skin of immunoglobulin E, an important class of immunoglobulin mediating allergic reactions. A fragment of the human myeloma ND epsilon-chain gene, encoding the second, third and fourth domains of the IgE constant region (C epsilon 2-4) was assessed here for its ability to inhibit the P-K reaction in vivo. Injection of the fragment in skin sites of healthy human adults prevented subsequent sensitization with serum containing IgE antibody to ragweed antigen. Inhibition of the P-K reaction required a 200-fold molar excess of the C epsilon fragment over the IgE present in the sensitizing serum. The efficacy of the C epsilon fragment in inhibiting the P-K reaction compared favourably with that of natural myeloma IgE (PS) in terms of both blocking concentrations and duration of the blocking effect. The inhibition of the P-K reaction by C epsilon 2-4 fragments was specific and probably caused by the saturation of IgE receptors on mast cells by the recombinant gene product. 相似文献
103.
The intact 741 bp polyhedrin gene of LsNPV was sequenced by Silver, Sequencing System, and shares 90.6% and 97.0% nucleotide
identity, 97.2% and 97.6% amino acid identity with PfNPV and MdNPV polh genes respectively. The 14 bp conservative sequence
with the core element GTAAG, is located in the 5′untranslated region of the gene. The polh gene was predicted to encodes a
246 amino acid residures with molecular weight of 29.0 kd, in which the number of acidic amino acids and alkaline amino acids
was roughly equal resulting in almost no charges in polyhedrin protein molecule and hence occlusion body. It gives a valuable
implication that ionic bonds as well as hydrophobic bonds and hydrogen bond may play an important role in the crystallization
of polyhedrin, by comparing amino acid variation of twenty—one polyhedrin. The comparsion of promoter regions of polyhedrin
gene and class II gene shown that they are very similar, but also have differences in GC content. This could explain that
both categories of gene are highly expressed, and polyhedrin genes are expressed more higher than class II gene.
Wang Jiawang: born in 1962, Doctor of science. Present address: Cancer Institute, CAMS, Beijing 100005 相似文献
104.
105.
Gould SJ 《Natural history》1984,93(2):14, 16, 18, passim
The author reflects on presentations at an annual meeting of the Geological Society of America regarding the differences between Ediacaran fauna fossils and fossils from the Cambrian evolutionary explosion. The theory presented by Dolf Seilacher attributes the differences between Ediacaran animals and their modern counterparts to structure. He proposes that Ediacaran fauna were a failed evolutionary experiment. Related comments and meeting presentations are included. 相似文献
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108.
Control of segment number in vertebrate embryos 总被引:1,自引:0,他引:1
The vertebrate body axis is subdivided into repeated segments, best exemplified by the vertebrae that derive from embryonic somites. The number of somites is precisely defined for any given species but varies widely from one species to another. To determine the mechanism controlling somite number, we have compared somitogenesis in zebrafish, chicken, mouse and corn snake embryos. Here we present evidence that in all of these species a similar 'clock-and-wavefront' mechanism operates to control somitogenesis; in all of them, somitogenesis is brought to an end through a process in which the presomitic mesoderm, having first increased in size, gradually shrinks until it is exhausted, terminating somite formation. In snake embryos, however, the segmentation clock rate is much faster relative to developmental rate than in other amniotes, leading to a greatly increased number of smaller-sized somites. 相似文献
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110.
c-Myc-regulated microRNAs modulate E2F1 expression 总被引:8,自引:0,他引:8