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11.
Generation and migration of cells in the developing striatum. 总被引:8,自引:0,他引:8
The development of the rat striatum was investigated using a combination of two histochemically distinguishable retrovirus vectors. Using this method, it was possible to identify clonal boundaries within the embryonic striatum and thus determine patterns of proliferation, migration, and some lineal relationships. Several novel aspects of striatal histogenesis were discovered. Striatal progenitor cells do not exhibit a stem cell pattern of division between embryonic day 15 (E15) and E19; a progenitor-progeny relationship appears to exist for ventricular zone and subventricular zone (SVZ) cells; striatal progenitors produce a variety of clone types; some SVZ cells migrate radially, and some migrate tangentially within the SVZ; and radial glia and presumptive neurons can occur in the same clone. 相似文献
12.
13.
Moran Jonathan A.; Merbach Marlis A.; Livingston Nigel J.; Clarke Charles M.; Booth Webber E. 《Annals of botany》2001,88(2):307-311
Old World pitcher plants (Nepenthes spp., Nepenthaceae) trapand digest invertebrate prey to derive nutrients, primarilynitrogen (N). In the majority of lowland Nepenthes species studiedto date, ants (Hymenoptera, Formicidae) are numerically thedominant prey taxon. Nepenthes albomarginata is unusual in showingan apparent bias towards the capture of termites (Isoptera).We tested the hypothesis that N. albomarginata derives N fromtermite capture, by comparison of foliar stable N isotope abundance( 相似文献
14.
Geoffrey W. Krissansen Patricia A. Gorman Christine A. Kozak Nigel K. Spurr Denise Sheer Peter N. Goodfellow Michael J. Crumpton 《Immunogenetics》1987,26(4-5):258-266
The gene coding for the M
r 26000 chain of the human CD3 (T3) antigen/T-cell antigen receptor complex was mapped to chromosome band 11q23 by using a cDNA clone (pJ6T3 -2), by in situ hybridization to metaphase chromosomes and by Southern blot analysis of a panel of human-rodent somatic cell hybrids. The mouse homolog, here termed Cdg-3, was mapped to chromosome 9 using the mouse cDNA clone pB10.AT3 -1 and a panel of mouse-hamster somatic cell hybrids. Similar locations for the CD3
genes have been described previously. Thus, the corporate results indicate that the CD3
and genes have remained together since they duplicated about 200 million years ago. 相似文献
15.
Homozygous lymphoblastoid cell lines representing various Dw subtypes of DR2 were examined for polymorphism at the DQ
locus by molecular and cellular techniques. The subtypes studied included Dw2, Dw12, and a group heterogenous by cellular typing that we shall refer to as non-Dw2/non-Dw12. Restriction fragment length polymorphism analysis of cell lines representing these subtypes revealed DQ
-specific patterns consistent with cellular typing. Two-dimensional gel electrophoresis of DQ molecules from representative cell lines revealed a structural polymorphism of DQ
among the three subtypes. The DQ
chain migrated to a position that was unique to each subtype and was consistent among various representative cell lines of each subtype. Nucleotide sequence analysis of cDNA clones of DQ
from Dw2, Dw12, and non-Dw2/non-Dw12 lines confirmed that the variability resided at the genetic level. Variability was found in the form of numerous scattered nucleotide substitutions throughout the first domain of these alleles. The DQ
gene of the non-Dw2/non-Dw12 cell line AZH was further found to be almost identical with the DQ
gene of a DR1 line (Bell et al. 1985b), implicating a common evolutionary origin of these alleles. The only difference between these two sequences was due to an apparent gene conversion event at amino acid 57. T-cell cloning experiments resulted in the derivation of Epstein-Barr virus-specific, DQw1-restricted clones that proliferated against only those cell lines that exhibited the DQ
gene common to AZH and the DR1 cell line. Thus, the polymorphism among DQ
alleles within DR2 results in subtype-specific restriction. 相似文献
16.
Nigel J. Fuller Dorothy M. Stirling Stephen Dunnett Gavin P. Reynolds Margaret Ashwell 《Bioscience reports》1987,7(2):121-127
The effects of reducing brain serotonin (5-HT) levels by means of intracerebral-ventricular injections of the tryptophan antagonist p-chlorophenylalanine (PCPA) were investigated in male rats. Six days after the operation, PCPA-treated rats, either fedad libitum or pair-fed to the food intake of control rats, showed decreased thermogenic activity and capacity in their interscapular brown adipose tissue (BAT) and also increased fat storage in their white adipose tissue (WAT). These results indicate that serotonergic synapses might play a regulatory role in the sympathetic control of BAT thermogenesis and in the rate of WAT deposition (by an as yet unidentified mechanism), in addition to their well established role in controlling food intake. 相似文献
17.
Nigel W. Kerby Gordon W. Niven Peter Rowell William D. P. Stewart 《Applied microbiology and biotechnology》1987,25(6):547-552
Summary Mutant strains of the N2-fixing cyanobacterium bacterium Anabaena variabilis resistant to 6-fluorotryptophan or to ethionine were isolated. Many of these strains liberated amino acids into their media in the absence of 6-fluorotryptophan and ethionine. Nitrogenase activity was higher in mutant strains than in the parent strain. Mutant strains were immobilised in calcium alginate and sustained photoproduction of amino acids has been demonstrated.Abbreviations ETH
ethionine
- FT
6-fluorotryptophan
- Hepes
4-(2-hydroxyethyl)-1, piperazine ethanesulphonic acid
- PEP
phosphoenolpyruvate
- DAHP
3-deoxy-d-arabinoheptulosonate 7-phosphate
- chl a
chlorophyll a 相似文献
18.
Chromosome Specificity of Polysomy Promotion by Disruptions of the Saccharomyces cerevisiae RNA1 Gene 总被引:2,自引:1,他引:1
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Previously, we showed that a disruption of the yeast RNA1 gene with LEU2 sequences promotes polysomy for chromosome XIII. Here we demonstrate that this phenotype is due to sequences specific to the RNA1 gene and that the disruption allele does not affect nondisjunction of three other chromosomes or polysomy of a minichromosome. Hence polysomy appears to be restricted to chromosome XIII. 相似文献
19.
Marion H. Brown Patricia A. Gorman William A. Sewell Nigel K. Spurr Denise Sheer Michael J. Crumpton 《Human genetics》1987,76(2):191-195
Summary A cDNA clone encoding the human T lymphocyte sheep erythrocyte receptor [the CD2 (T11) antigen] was used as a probe to define the chromosomal location of the gene. The signal, revealed by hybridisation to Southern blots of genomic DNA from somatic cell hybrids, showed a high degree of concordance for human chromosome 1. In particular, the hybrid F4Sc13C19 which contained the short arm only of human chromosome 1 was positive. The location of the CD2 gene to 1p13 was confirmed by in situ hybridisation. 相似文献
20.
Effect of maltose on the response of potato anthers in culture 总被引:1,自引:0,他引:1
Anthers of the Solanum tuberosum genotype H3703 were cultured on medium containing equimolar concentrations of sucrose or maltose. It was found that significantly more pollen embryos became plants after culture on maltose and hence the yield of plants per 100 anthers cultured increased significantly. Mechanisms by which carbohydrate source may influence response to anther culture are discussed. 相似文献