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Three P-transposable vectors (approx. 16, 12, and 9 kb) were constructed containing a hsp82-neo fusion gene encoding a truncated heat-shock protein 82 of Drosophila pseudoobscura and the bacterial neomycin phosphotransferase (NPT). In transgenic Drosophila melanogaster, hsp82-neo exhibits high levels of housekeeping gene promoter and NPT activities in all cells in the absence of heat-shock and is further induced (fivefold) by elevated temperatures (35 degrees-36 degrees C). The hsp82-neo selection of transformants is possible from embryo to adulthood. The hsp82-neo insertion in a P-element plasmid carrying an alcohol-dehydrogenase-encoding gene (Adh) produced plasmids pHS22 (approx. 16 kb) and pHS24 (approx. 12 kb), in which both genes were expressed, as observed in 13 transgenic strains. Cloning of DNA fragments up to at least 16 kb in a third vector, pHS85 (approx. 9 kb), lacking the Adh cointegrate is facilitated by a 104-bp multiple cloning site (MCS) positioned downstream (3') from hsp82-neo. To accept inserts of nonselectable foreign genes, MCS provides 20 restriction sites, eight of them unique. The hsp82-neo-expressing vectors also function in cell-culture transfection assays. The hsp82-neo fusion gene (3.73 kb) may be of wide application as a dominant selection marker in other animal systems and plants. 相似文献
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Hepatic arterial infusion chemotherapy (HAIC) for unresectable hepatic neoplasms has been associated with gastric ulcers and epithelial atypia that may be misinterpreted as carcinoma. Gastric brushings were reviewed from six patients who developed gastric ulcers with histologically proven atypia following HAIC. Marked cytologic atypia, reminiscent of a pronounced radiation effect, was present in gastric epithelial cells in five patients. The atypical cells occurred singly or in small sheets. They were markedly enlarged but a low nuclear-cytoplasmic ratio was preserved. The abundant cytoplasm was vacuolated or foamy. Binucleation and multinucleation were common, and massive nucleoli were characteristic. The brushings also contained the reparative, inflammatory and necrotic changes associated with usual benign gastric ulcers. The bizarre atypia associated with HAIC can be a source of misdiagnosis of cancer in cytologic as well as in histologic specimens. 相似文献
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Signals of tens up to hundreds of thousands of (mostly olfactory) receptor cells on an insect antenna are switched to a comparatively low number of neurones in the antennal lobe of the deutocerebrum in circumscribed units of neuropile, the glomeruli. Each glomerulus is connected via its output neurone to two separate neuropiles (calyces of mushroom body, and lateral lobe) of the protocerebrum. Local interneurones interconnect between the glomeruli. Certain modes of convergence between receptors and central neurones provide for a very high sensitivity of the latter to certain odours and their sensitivity for complex odour stimuli, and in many cases for a marked multimodality. Anatomical and physiological data are given especially for pheromone sensitive neurones and their projections. 相似文献
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Hardies SC; Martin SL; Voliva CF; Hutchison CA d; Edgell MH 《Molecular biology and evolution》1986,3(2):109-125
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C Sass M Briand S Benslimane M Renaud Y Briand 《The Journal of biological chemistry》1989,264(7):4076-4081
Two cDNA clones were isolated, one corresponding to the mRNA coding for lactate dehydrogenase-M (LDH-M), the other to the mRNA coding for lactate dehydrogenase-H (LDH-H). The cDNA inserts consist of the entire open reading frame for LDH-M and a partial sequence, from amino acid 117 to 332, for LDH-H. Using these two clones as probes we demonstrate that: (a) the abundance of mRNA is muscle-type dependent; (b) the ratio M/H subunit for protein and mRNA is well related in the muscles studied; and (c) the M + H mRNA level is not relative to the total LDH activity. 相似文献
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A major difference between the divergence patterns within the lines-1 families in mice and voles 总被引:3,自引:0,他引:3
Vanlerberghe F; Bonhomme F; Hutchison CA d; Edgell MH 《Molecular biology and evolution》1993,10(4):719-731
L1 retroposons are represented in mice by subfamilies of interspersed
sequences of varied abundance. Previous analyses have indicated that
subfamilies are generated by duplicative transposition of a small number of
members of the L1 family, the progeny of which then become a major
component of the murine L1 population, and are not due to any active
processes generating homology within preexisting groups of elements in a
particular species. In mice, more than a third of the L1 elements belong to
a clade that became active approximately 5 Mya and whose elements are >
or = 95% identical. We have collected sequence information from 13 L1
elements isolated from two species of voles (Rodentia: Microtinae: Microtus
and Arvicola) and have found that divergence within the vole L1 population
is quite different from that in mice, in that there is no abundant
subfamily of homologous elements. Individual L1 elements from voles are
very divergent from one another and belong to a clade that began a period
of elevated duplicative transposition approximately 13 Mya. Sequence
analyses of portions of these divergent L1 elements (approximately 250 bp
each) gave no evidence for concerted evolution having acted on the vole L1
elements since the split of the two vole lineages approximately 3.5 Mya;
that is, the observed interspecific divergence (6.7%-24.7%) is not larger
than the intraspecific divergence (7.9%-27.2%), and phylogenetic analyses
showed no clustering into Arvicola and Microtus clades.
相似文献
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