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161.
H Banerjee Z Hawkins J Williams M Blackshear C Sawyer L Cezares S K Pramanik A Williams 《Cellular and molecular biology, including cyto-enzymology》2004,50(6):733-736
The protein chip surface enhanced laser desorption/ionisation (SELDI) technique is a highly versatile analytical mass spectrometry system with considerable potential for detection, identification and quantitation of protein complex mixtures. Astrocytoma is a tumour of the astrocytes with a very poor prognosis. There is no effective biomarker system for detection of astrocytoma. The SELDI technique was used to study differential protein expression in astrocytoma cells in comparison to normal brain astrocytes. Several novel proteins were found to be expressed in the astrocytoma cells, not present in the astrocytes. 相似文献
162.
David Chagné Chris Kirk Natalie How Claire Whitworth Cristian Fontic Gemma Reig Greg Sawyer Simon Rouse Lara Poles Susan E. Gardiner Satish Kumar Richard Espley Richard K. Volz Michela Troggio Ignasi Iglesias 《Tree Genetics & Genomes》2016,12(4):67
The red skin color desired by most apple consumers is not easy to achieve in warm climates, as the expression of MYB10, which regulates red pigmentation in apple, is influenced negatively by high temperatures. We describe the development and validation of a genetic marker for red skin coloration that effectively predicts color in a warm summer environment in Spain, as well as more temperate climates in New Zealand and Italy. Following the determination of a major-effect quantitative trait locus (QTL) controlling red skin coloration on linkage group (LG)9, using four segregating populations grown in New Zealand, and screened using the IRSC apple 8-K single-nucleotide polymorphism (SNP) array, the most significant SNP marker (ss475879531) was transformed into a marker suitable for use in a real-time PCR assay. This marker was validated using five apple seedling populations growing in a warm summer environment in Spain, demonstrating that the marker system efficiently predicts red skin coloration and can be used for marker assisted selection, even under conditions considered adverse for skin color development. 相似文献
163.
Statistical tests for detecting gene conversion 总被引:46,自引:18,他引:28
Statistical tests for detecting gene conversion are described for a sample
of homologous DNA sequences. The tests are based on imbalances in the
distribution of segments on which some pair of sequences agrees. The
methods automatically control for variable mutation rates along the genome
and do not depend on a priori choices of potentially monophyletic subsets
of the sample. The tests show strong evidence for multiple intragenic
conversion events at two loci in Escherichia coli. The gnd locus in E. coli
shows a highly significant excess of maximal segments of length 70-200 bp,
which suggests conversion events of that size. The data also indicate that
the rate of these short conversion events might be of the order of neutral
mutation rate. There is also evidence for correlated mutation in adjacent
codon positions. The same tests applied to a locus in an RNA virus were
negative.
相似文献
164.
Statistical analyses of DNA sequences of globin genes (beta A, beta C, and
gamma) from goat and sheep (including new sequence information for the
second intron of sheep beta A and gamma, kindly provided by A. Davis and A.
W. Nienhuis) indicate that the rates of nonsynonymous substitution in these
genes have been greatly accelerated following the gene duplication
separating gamma and the ancestor of beta A and beta C and the gene
duplication separating beta A and beta C. In both cases the acceleration
was apparently due to relaxation of purifying selection (functional
constraints) rather than advantageous mutations because acceleration
occurred only in less important parts of the beta globin chain. The rates
of nonsynonymous substitution in these genes are estimated to be about 2.3
x 10(-9) per site per year, which is three times higher than that for the
divergence between human beta and mouse beta major globin genes. Our
analyses further suggest that the rate of synonymous substitution in
functional genes and the rate of substitution in pseudogenes are
approximately equal and are between 2.8 x 10(-9) and 5.0 x 10(-9) and that
the rate of substitution in introns is about 3.0 x 10(-9). The divergence
time between beta A and beta C and that between gamma and the beta A-beta C
pair are about 12 and 30 million years, respectively. The proportion of
transition mutations is estimated to be 64%, two times higher than expected
under random mutation but considerably lower than the 96% estimated for
animal mitochondrial DNA.
相似文献
165.
Rearrangement of the keratin cytoskeleton after combined treatment with microtubule and microfilament inhibitors 总被引:3,自引:3,他引:0
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In addition to containing microtubule and microfilament systems, vertebrate epithelial cells contain an elaborate keratin intermediate-filament cytoskeleton. Little is known about its structural organization or function. Using indirect immunofluorescence microscopy with an antikeratin antiserum probe, we found that destabilization of microtubules and microfilaments with cytostatic drugs induces significant alterations in the cytoskeletal organization of keratin filaments in HeLa and fetal mouse epidermal cells. Keratin filament organization was observed to undergo a rapid (1-2 h) transition from a uniform distribution to an open lattice of keratin fibers stabilized by membrane-associated focal centers. Since addition of any one drug alone did not elicit significant organizational change in the keratin cytoskeleton, we suggest that microfilaments and microtubules have a combined role in maintaining the arrangement of keratin in these cells. Vimentin filaments, the only other intermediate-sized filaments found in HeLa cells, did not co-distribute with keratin in untreated or drug-treated cells. These findings offer a new way to approach the study of the dynamics and functional roles of the keratin cytoskeleton in epithelial cells. 相似文献
166.
The behavioral effects of alpha-melanocyte stimulating hormone (alpha-MSH) were compared to an alpha-MSH analogue that had a norleucine substituted for methionine in the four position and a D-phenylalanine substituted for L-phenylalanine in the seven position. [Nle4, D-Phe7]-alpha-MSH has previously been shown to be a superpotent agonist on melanocytes [17]. The present experiments indicate that [Nle4, D-Phe7]-alpha-MSH is equipotent to alpha-MSH in inducing grooming when administered intraventricularly. In contrast, the analogue has the opposite effect of alpha-MSH on performance of a visual discrimination task. alpha-MSH improves visual performance whereas [Nle4, D-Phe7]-alpha-MSH attenuates such performance. The contrasting activities of [Nle4, D-Phe7]-alpha-MSH on the physiological processes described suggest that this analogue may interact with three distinct melanotropin receptors in different ways. On melanocyte receptors the melanotropin analogue is a superagonist, on CNS melanotropin receptors involved in grooming it is equipotent to alpha-MSH, and on CNS receptors involved in attention, learning and memory [Nle4, D-Phe7]-alpha-MSH may be an antagonist of endogenous melanotropin. 相似文献
167.
M Butler W K Sawyer T Giannina B G Steinetz 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1975,149(2):506-510
We have studied several parameters of prostate function in two inbred lines (2.4 and SsLak) of young and old LSH hamsters. These included weight, acid phosphatase, and [3H]testosterone uptake as influenced by age, castration, and androgen treatment. In the hamster, prostatic acid phosphatase concentration was found to vary inversely with androgen levels, contrary to the usual assumption that this enzyme is androgen dependent. Prostatic uptake of tritiated testosterone was enhanced by castration and by treatment of castrates with doses of androgen which induced a moderate increase in gland size. With advancing age, the prostates of LSH hamsters (both strains) became atrophic rather than hyperplastic, in contrast with a previous report (1). This atrophy appeared to be a consequence of decreased testicular function. The LSH hamsters appear to be a suitable model for the study of senescent changes in the male reproductive system. 相似文献
168.
Order of the ilv genes of Salmonella montevideo 总被引:1,自引:0,他引:1
Summary
Ilv mutants of aSalmonella typhimurium-Salmonella montevideo hybrid were used in cotransduction studies to obtain evidence for the order of theilv genes ofS. montevideo. The following order, which is the same as that previously reported forS. typhimurium, is derived:ilvE-ilvD-ilvA-ilvC.From the Departments of Genetics and Biochemistry, School of Agriculture and Life Sciences, and School of Physical and Mathematical Sciences, North Carolina State University, Raleigh, North Carolina 27607. Paper No. 3300 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh, North Carolina. Supported by Research Grant GM 14184-04 from the Public Health Service. 相似文献
169.
Transcription of DNA from the 70S RNA of Rous Sarcoma Virus II. Structure of a 4S RNA Primer 总被引:32,自引:19,他引:13
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A. J. Faras J. E. Dahlberg R. C. Sawyer F. Harada J. M. Taylor W. E. Levinson J. M. Bishop H. M. Goodman 《Journal of virology》1974,13(5):1134-1142
The 70S RNA of Rous sarcoma virus contains 4S RNAs which serve as primers for the initiation of DNA synthesis in vitro by the RNA-directed DNA polymerase of the virus. We purified these primers in three different ways-by isolation of the covalent complex between primer and nascent DNA, by differential melting of the 70S RNA, and by two-dimensional electrophoresis in polyacrylamide gels. The 4S RNAs purified by these procedures were homogeneous and possessed very similar if not identical nucleotide compositions and sequences. The RNAs were approximately 75 nucleotides long, had pG at the 5' terminus and CpCpA(OH) at the 3' terminus, and contained a number of minor nucleotides characteristic of tRNA. In contrast to most tRNA's, the primer lacked rTp and contained Gp (Psip, Psip, Cp) Gp (possibly in place of the characteristic sequence GprTpPsipCpGp). At least 50% of the 4S primers available on 70S RNA were utilized in a standard polymerase reaction in vitro. 相似文献
170.
Chemical and physical properties of an arabinogalactan-peptide from wheat endosperm 总被引:12,自引:2,他引:10
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1. An arabinogalactan-peptide from wheat endosperm was studied by using physicochemical techniques and some aspects of its chemical structure were determined. 2. The arabinogalactan-peptide is a non-associating, polydisperse macromolecule ([unk]=22000) which exhibits only minor non-ideal effects in aqueous solution. 3. Examination of the products of partial acid hydrolysis of the polysaccharide component showed that arabinose is present in the alpha-l-arabinofuranosyl configuration, and i.r.-absorption spectroscopy and optical-rotation studies suggest that the d-galactopyranose residues are linked by glycosidic linkages in the beta-anomeric configuration. 4. The arabinogalactan is linked to a peptide which represents 8% (w/w) of the arabinogalactan-peptide and which may be present as a molecular core. Partial degradation of the polymer by successive treatment with oxalic acid and NaOH showed that the linkage between polysaccharide and peptide involves galactose and hydroxyproline residues and is glycosidic in nature. A tentative model is proposed for the structure of the wheat endosperm arabinogalactan-peptide. 5. The subcellular location and function of the arabinogalactan-peptide is discussed in relation to previous work with related molecules. 相似文献