In an earlier report we showed that the 5' end of the gene for ataxia telangiectasia ATM is within 700 bp of the 5' end of a novel gene E14, and suggested that the CpG island that separates these genes functions as a bidirectional promoter. We have now determined the complete amino acid sequence of the E14 protein, defined the exon/intron structure of the gene and estimate that the complete gene is more than 55 kb in length. The E14 gene appears to be a housekeeping gene that is expressed in all tissues, including all parts of the brain. The E14/ATM promoter organisation is conserved in man, monkey and mouse, although the mouse promoter is more compact and appears to lack two of the four putative Sp1 boxes found in the human promoter. Reporter gene constructs showed that the human and mouse E14/ATM promoters were indeed bidirectional, that the ATM side of the human promoter was three times stronger than the E14 side, and that the mouse promoter (in human cells) directed transcription with equal efficiency in both directions, but at a lower level than the human promoter. Analysis of a small number of A-T patients for mutations in the promoter region or the E14 coding sequence did not provide evidence to suggest that E14 contributes to the A-T phenotype.
Exhumed hydrocarbon traps are globally rare but can offer important insight to subsurface systems, not available through the collection of standard industry data sets. Core, wireline and seismic data leave significant scale gaps which only high quality mega-scale outcrops can fill. East Greenland contains world class examples of exhumed hydrocarbon traps, in both scale and the quality of exposure. Difficulty in accessing this remote region has left these features relatively understudied. This study first examines the age of the strata involved within the exhumed traps. Biostratigraphic and provenance analysis were carried out so as both the local and regional context of the hydrocarbon staining could be understood. This is of particular importance for future exploration strategies in the North Atlantic region. The second aim of this
Biofilms containing diverse microflora were developed on bitumen-painted steel and glass tiles suspended in a chemostat model of a water distribution system. Escherichia coli, taken from a naturally occurring biofilm, was transformed with a plasmid containing the anaerobically induced nirB promoter fused to the lacZ reporter gene. The resulting transformant, PRB1, was introduced into the chemostat. After 7 and 13 days, an E. coli strain with an anaerobically induced Lac+ phenotype was present in the biofilm. Development of an episcopic differential interference contrast technique combined with UV fluorescence microscopy enabled the simultaneous visualization of E. coli in the biofilm using a fluorescent probe to detect expression of the gusA reporter gene and a lacZ fluorescent probe to monitor anaerobic expression of beta-galactosidase from pnirB.
The Colorado River in the SW of the USA is one of Earth's few continental-scale rivers with an active margin delta. Deformation along this transform margin, as well as associated intra-plate strain, has resulted in significant changes in sediment routing from the continental interior and post-depositional translation of older deltaic units. The oldest candidate deposits, fluvial sandstones of the Eocene Sespe Group, are now exposed in the Santa Monica Mountains, 300 km to the north of the Colorado River. Heavy mineral data from this basin indicate that sediment was sourced by a large river system, with some affinity to the early Pliocene Colorado River, but was unlikely to have been integrated across the Colorado Plateau. Sedimentological and mineralogical evidence from the earliest (c. 5.3 Ma) unequivocal Colorado River-derived sediments in the Salton Trough provide evidence for a rapid transition from locally derived sedimentation. Lack of evidence for a precursor phase of suspended-load sediment suggests that drainage capture took place in a proximal position, favouring a ‘top-down’ process of lake spillover. Following drainage integration, significant changes in heavy mineral assemblages of fluvio-deltaic sediments, particularly evident from apatite–tourmaline and garnet–zircon indices, as well as U–Pb ages of detrital zircons, document the integration of the fluvial system to its present form and progressive incision of the Colorado Plateau from the Miocene to the present.
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