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11.
12.
Cedar M. Chittenden Kevin G. Butterworth K. Fiona Cubitt Melinda C. Jacobs Adrian Ladouceur David W. Welch R. Scott McKinley 《Environmental Biology of Fishes》2009,84(1):129-140
Many coho salmon stocks (Oncorhynchus kisutch) have been in decline during the past three decades. Canada’s most endangered salmon stock, the Thompson River coho salmon,
is being studied extensively as managers attempt to reverse these population declines. Investigators are using acoustic telemetry
to track the migratory behaviour and survival of the Thompson River (and other) coho salmon stocks. Coho salmon pre-smolts
are relatively small compared with salmonid species that are typically studied using acoustic telemetry; therefore the identification
of the appropriate sizes of fish and tags to use is critical. This study tested the effects of surgically implanting the three
smallest sizes of acoustic tags currently available on the growth, survival, tag retention, swimming performance and physical
condition of coho salmon pre-smolts for 300 days post-surgery. Maximum tag size to body size ratios ranged from 15–17% by
fork length and 7–8% by mass for the three tag sizes (11 cm fork length for a 6 × 19 mm tag, 12.5 cm for a 7 × 19 mm tag,
and 14 cm for a 9 × 21 mm tag). Based on our results, it is unlikely that coho salmon pre-smolts implanted with acoustic transmitters
following these size guidelines would have poor survival in studies of freshwater migratory behaviour as a result of the surgery
or the tag. 相似文献
13.
Human Bak induces cell death in Schizosaccharomyces pombe with morphological changes similar to those with apoptosis in mammalian cells. 总被引:2,自引:0,他引:2
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B Ink M Zrnig B Baum N Hajibagheri C James T Chittenden G Evan 《Molecular and cellular biology》1997,17(5):2468-2474
Apoptosis as a form of programmed cell death (PCD) in multicellular organisms is a well-established genetically controlled process that leads to elimination of unnecessary or damaged cells. Recently, PCD has also been described for unicellular organisms as a process for the socially advantageous regulation of cell survival. The human Bcl-2 family member Bak induces apoptosis in mammalian cells which is counteracted by the Bcl-x(L) protein. We show that Bak also kills the unicellular fission yeast Schizosaccharomyces pombe and that this is inhibited by coexpression of human Bcl-x(L). Moreover, the same critical BH3 domain of Bak that is required for induction of apoptosis in mammalian cells is also required for inducing death in yeast. This suggests that Bak kills mammalian and yeast cells by similar mechanisms. The phenotype of the Bak-induced death in yeast involves condensation and fragmentation of the chromatin as well as dissolution of the nuclear envelope, all of which are features of mammalian apoptosis. These data suggest that the evolutionarily conserved metazoan PCD pathway is also present in unicellular yeast. 相似文献
14.
The biosynthesis of galactofuranosyl residues in galactocarolose 总被引:6,自引:2,他引:4
A. Garcia Trejo J. W. Haddock G. J. F. Chittenden J. Baddiley 《The Biochemical journal》1971,122(1):49-57
1. Cell-free extracts of Penicillium charlesii G. Smith were used in a study of the biosynthesis of the galactofuranose polymer, galactocarolose. 2. UDP-glucose and UDP-galactopyranose were precursors of galactocarolose and it was shown that the galactofuranose residues in the polymer were formed from glucose without fission of the hexose carbon chain. 3. A new nucleotide, UDP-alpha-d-galactofuranose, was formed by the system and was a major product when polymer synthesis was inhibited by F(-) or Zn(2+); the nucleotide was isolated and its structure determined. 4. UDP-alpha-d-galactofuranose was efficiently utilized for polymer synthesis and shown to be formed from the pyranose nucleotides. 5. A route for the biosynthesis of galactocarolose, involving a novel ring contraction of the hexose residue while still attached to the nucleotide, is proposed. 相似文献
15.
The specific substance from Pneumococcus type 34 (41). The phosphodiester linkages 总被引:6,自引:5,他引:1
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G. J. F. Chittenden W. K. Roberts J. G. Buchanan J. Baddiley 《The Biochemical journal》1968,109(4):597-602
1. The phosphate groups in the type-specific substance S.34 from Pneumococcus type 34 (U.S. type 41) were shown to join the hydroxyl group at position 1 or 5 of ribitol and the hydroxyl group at position 3 of a d-galactofuranosyl residue in the next repeating unit. 2. A partial structure of the type-specific substance was derived. 3. New syntheses of d-galactose 2-phosphate and d-galactose 3-phosphate are described. 相似文献
16.
17.
Structure and function of amylases. I. The subunit structure of porcine pancreatic -amylase 总被引:1,自引:0,他引:1
The isozymes of porcine pancreatic α-amylase were reduced with dithiothreitol to two enzymatically active subunits which had molecular weights of 25,000 daltons each. These subunits could be isolated and separated from each other by chromatography on DEAE-cellulose. Subsequent treatment of the subunits with EDTA, DTT, and iodoacetamide gave derivatives that emerged in identical elution volumes from DEAE-cellulose columns and that migrated very rapidly and identically on disc-gel electrophoresis. These latter experiments suggested that the subunits might have similar primary structures. This hypothesis was tested by preparing tryptic peptide maps of the subunits. The results indicated that the subunits had very similar, if not identical, primary structures. 相似文献
18.
The phosphorylation of thymidine has been studied in a model evaporating pond environment. Evaporation of dilute solutions of thymidine and ammonium oxalate in the presence of apatite leads to the synthesis of nucleotides. The presence of organic compounds such as cyanamide or urea substantially increases the yields of products. Solutions of cyanogen, when heated and evaporated in the presence of nucleoside and apatite, produce similarly high yields of nucleotide without added condensing agents. The mechanism of the reaction appears to involve the hydrolysis of cyanogen to produce ammonium oxalate and urea, among other products. An evolutionary continuum leading from the cosmically abundant CN moiety to the establishment of conditions favorable for phosphorylation on the primitive earth is suggested. 相似文献
19.
The synthesis of 2(R),3-dihydroxypropyl and 2(R),3(R)-dihydroxybutyl β-d-fructopyranosides, and some derivatives, employing Sharpless-type catalytic asymmetric dihydroxylation procedures is described. Some aspects of the reactions, including stereoselectivities and chemical evidence for the assigned stereochemistry of the main products are reported. 相似文献
20.
Chittenden TW Pak J Rubio R Cheng H Holton K Prendergast N Glinskii V Cai Y Culhane A Bentink S Schwede M Mar JC Howe EA Aryee M Sultana R Lanahan AA Taylor JM Holmes C Hahn WC Zhao JJ Iglehart JD Quackenbush J 《PloS one》2010,5(12):e15581
GIPC1 is a cytoplasmic scaffold protein that interacts with numerous receptor signaling complexes, and emerging evidence suggests that it plays a role in tumorigenesis. GIPC1 is highly expressed in a number of human malignancies, including breast, ovarian, gastric, and pancreatic cancers. Suppression of GIPC1 in human pancreatic cancer cells inhibits in vivo tumor growth in immunodeficient mice. To better understand GIPC1 function, we suppressed its expression in human breast and colorectal cancer cell lines and human mammary epithelial cells (HMECs) and assayed both gene expression and cellular phenotype. Suppression of GIPC1 promotes apoptosis in MCF-7, MDA-MD231, SKBR-3, SW480, and SW620 cells and impairs anchorage-independent colony formation of HMECs. These observations indicate GIPC1 plays an essential role in oncogenic transformation, and its expression is necessary for the survival of human breast and colorectal cancer cells. Additionally, a GIPC1 knock-down gene signature was used to interrogate publically available breast and ovarian cancer microarray datasets. This GIPC1 signature statistically correlates with a number of breast and ovarian cancer phenotypes and clinical outcomes, including patient survival. Taken together, these data indicate that GIPC1 inhibition may represent a new target for therapeutic development for the treatment of human cancers. 相似文献