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61.
Summary New cell lines, designated as ML-DmDl≈10, were established from dissociated imaginal discs ofDrosophila melanogaster. The culture medium was prepared by mixing in a 1:1 ratio Cross and Sang’s M3(BF) medium, supplemented with 10% heat inactivated
fetal bovine serum (FBS), with the supernatant of a primary embryonic cell culture made in the M3(BF) medium and supplementing
this mixture with insulin. One cell line was established in the medium containing larval hemolymph instead of the primary
culture supernatan, and another was established in fresh M3(BF) medium supplemented with insulin and FBS. In these mediums,
imaginal disc cells first formed aggregates and cellular vesicles within a few weeks followed by the proliferation of thin-layered
cells around them after about 1 mo. Ten cell lines have so far been established from two kinds of imaginal discs and disc
mixtures. The ploidy of these cell lines was predominantly diploid. Population doubling time was about 50 to 70 h at 3 to
10 mo. after initiation of the culture. When the cell aggregates formed in vitro were implanted in metamorphosing larvae,
they differentiated at high frequency into adult cuticular strutures in the early phase of the primary culture. This differentiation
of aggregates was also observed, though at low frequency, in a culture maintained by dilution-transfer for 6 to 15 mo. in
vitro. 相似文献
62.
The subcellular distribution of Ca2+/calmodulin-stimulated adenylate cyclase activity was studied in comparison with that of guanine nucleotide-stimulated cyclase activity. The distributions of these activities were similar among the crude fractions but differed among the purified subsynaptosomal fractions. The specific activity of Ca2+/calmodulin-stimulated cyclase was highest in a light synaptic membrane fraction, which has few, if any, postsynaptic densities, whereas that of guanine nucleotide-stimulated cyclase was highest in a heavier synaptic membrane fraction rich in postsynaptic densities. These results suggest that the Ca2+/calmodulin-stimulated cyclase has, at least in part, a different cellular or subcellular location than the guanine nucleotide-stimulated cyclase.Abbreviations used CaM
calmodulin
- GppNHp
guanosine 5-(,-imino) triphosphate 相似文献
63.
Journal of Plant Research - The vascular anatomy of seven genera of Magnoliaceae:Elmerrillia, Liriodendron, Magnolia, Manglietia, Michelia, Paramichelia andTalauma, was examined. Based on the... 相似文献
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Kaoru Saigo Ryu Ueda Tadashi Miyake 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1983,740(4):390-401
In a previous communication (Saigo, K., Millstein, L. and Thomas, C.A., Jr. (1981) Cold Spring Harbor Symp. Quant. Biol. 45, 815–827), the overall structure of histone genes of Schneider line 2 cells was shown to extensively differ from that of Oregon-R embryo from which the cell line was established, and it was speculated that the histone genes might be reshuffled extensively during either the periods of the establishment, or maintenance of cell lines, or both. To establish the validity of this notion the structure of histone genes was examined in Drosophila melanogaster cultured cells. The overall organization of histone gene clusters was found to be stably maintained in both the periods for the establishment and maintenance of cultured cells, indicating that the previous assumption is inadequate. Instead of an extensive rearrangement, minor structural changes were found to occasionally occur probably by simple base substitutions and/or, deletion or insertion of very short DNA pieces. It was also shown that the extensive variation in structures of histone genes in cultured cells such as Schneider line 2 are attributable to polymorphism on the level of individual flies. 相似文献
67.
Chemical modification of cytosine residues of U6 snRNA with hydrogen sulfide (nucleosides and nucleotides. Part 49 [1]). 总被引:3,自引:1,他引:2 下载免费PDF全文
Sulfhydrolysis of cytosine residues to 4-thiouracil residues in mouse U6 snRNA was carried out to examine the secondary structure of U6 snRNA. The cytosine residues at positions 6, 42 and 68 were modified significantly, and at positions 11, 19 (or/and 25), 61 and 66 in moderate extent. Based on the result, the plausible secondary structure of U6 snRNA is discussed. 相似文献
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