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11.
Josefa Alamillo Concepción Almoguera Dorothea Bartels Juan Jordano 《Plant molecular biology》1995,29(5):1093-1099
Using antibodies raised against two sunflower small heat shock proteins (sHSPs), we have detected immunologically related proteins in unstressed vegetative tissues from the resurrection plant Craterostigma plantagineum. In whole plants, further accumulation of these polypeptides was induced by heat-shock or water-stress. In desiccation-intolerant Craterostigma callus tissue, we failed to detect sHSP-related polypeptides, but their expression, and the concurrent acquisition of desiccation tolerance was induced by exogenous abscisic acid (ABA) treatment. In untressed plants, the cross-reacting polypeptides were abundant in the roots and lower part of the shoots, where they showed homogeneous tissue-distributions. This constitutive expression is novel for vegetative tissues of higher plants, and resembles the expression patterns of sHSPs in desiccation-tolerant zygotic embryos and germinating seeds.J.A. and C.A. contributed equally to this work and are both considered to be first author 相似文献
12.
Lorraine Flaherty Linda Cantor Debra Zimmerman Dorothea Bennett 《Developmental biology》1977,59(2):237-240
Cell surface antigens of normal and anemic () mouse erythroid cells have been examined in cytotoxicity assays with two rat antisera. When tested on fetal liver cells, a rat anti-erythroblast serum recognized antigen(s) present on erythroid cells early in development, while rat anti-adult red blood cell serum recognized antigen(s) present on mature erythroid cells. Each of these sera had different activity on normal (+/+ or ) as compared to anemic () erythroid cells. 相似文献
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14.
Ferdinand Bohlmann Karl-Heinz Knoll Christa Zdero Pradip Kumar Mahanta Michael Grenz Albert Suwita Dorothea Ehlers Ngo Le Van Wolf-Rainer Abraham Arvind Anant Natu 《Phytochemistry》1977,16(7):965-985
Investigation of about 50 Senecio species has afforded many new substances, in addition to known compounds. Present in these plants are 23 fura 相似文献
15.
Serological studies relating F9 antigen of embryonal carcinoma cells to
at the murineT/t complex have been extended and confirm that only the lethal haplotype t12- and none of the other five lethal haplotypes-affects the quantitative expression of F9 antigen on sperm. Cytotoxicity tests on preimplantation embryos show that t12 homozygotes are less susceptible to antiF9 serum than tw5 homozygotes, and that using specific antimutant haplotype antisera prepared against sperm, t12 antigen is detectable on morulae, whereas tw5 antigen is not. 相似文献
16.
Based on SEM examinations of some 1600 species of monocotyledons out of 61 families the characteristics of their epicuticular waxes are described in this preliminary paper and illustrated by 20 SEM micrographs. Four basic types of waxes are recognized. Two of them occur throughout the monocotyledonous and dicotyledonous orders of angiosperms; two others are of high systematic significance and restricted to particular orders of the monocotyledons: The “Convallaria-Type” is characterized by fine wax platelets with parallel orientation, forming a pattern around the stomata reminiscent of electromagnetic field lines. This type is restricted to the three liliiflorous ordersAsparagales, Liliales, andBurmanniales. The “Strelitzia-Type” is characterized by massive compound wax rodlets; it is restricted to the superordersAreciflorae, Commeliniflorae, Zingiberiflorae, plus the two liliiflorous ordersBromeliales andVelloziales. The data are compared with the classifications ofDahlgren & Clifford (1982); they tentatively indicate the exclusion ofBromeliales, Velloziales, andTyphales from theLiliiflorae. 相似文献
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A series of recessive mutations which arrest embryonic development are located within the T/t region of chromosome 17 in the mouse. To assess whether these mutations cause death in specific differentiating cells or in all cells of the embryo, we removed the embryonic cells from normal developmental constraints and attempted to grow them ectopically in vivo and in vitro. We have succeeded in producing teratomas and teratocarcinomas by transplantation of inner cell masses from blastocysts of and genotypes. The ability of embryonic cells to grow as tumors was not affected by their genotype; 7 of the 17 tumors were homozygous for tw12, 7 were heterozygous, and 3 could not be analyzed. Virtually all the tumors of both genotypes contained derivatives of all three germ layers. Neuroepithelial and mature nervous tissue was present in all homozygous tumors and all except one heterozygous tumor. However, no cartilage or bone was found in 5 of 5 tw12 homozygous tumors, while both tissues were present in 3 of 4 tw12 heterozygous tumors. This observation is compatible with the abnormalities characteristic of embryos, which show very localized effects in nervous tissue and more general effects on bone and cartilage formation. Cells derived from homozygous tumors were capable of at least limited growth in culture and a cell line has been derived from one of them. The p63/6.9a marker protein was used to determine the presence of the tw12 haplotype in the tumor and cultured cells. We conclude that the lethality associated with the tw12 haplotype is due to lethality of specific cells, and not all cell types. 相似文献
20.
The role of estrogens in the regulation of lactate dehydrogenase activity and its submolecular organization in rat anterior pituitary 总被引:1,自引:0,他引:1
Estrogens increase LDH activity and decrease H/M subunit ratio in rat anterior pituitary in both the experimental circumstances and the physiological conditions. The cellular messengers mediating estrogenic effect are structure- and stereospecific. The activity increasing and subunit ratio decreasing potency of the three tested estrogens was of following decreasing order: 17 beta-estradiol, estrone, and estriol. 17 alpha-estradiol did not affect activity parameters and submolecular organisation of the enzyme. The estrogen induced activity increase is consequence of the enhanced de novo enzyme protein synthesis which could be inhibited by Actinomycin-D. The lack of adrenocorticoids did not involve the alteration of LDH activity and H/M ratio in female rat anterior pituitary. Accordingly, these steroids do not mediate estrogenic action. 17 beta-estradiol had a substantial increasing effect on LDH activity in the subrenal implanted pituitary homografts and decreased H/M subunit ratio. Pituitary LDH activity in androgenized female rats decreased only after the removal of the polycystic ovaries. The two latter observations suggest that hypothalamic hormones are not involved in the regulation of pituitary LDH activity and its submolecular organization. De novo synthesis of LDH enzyme protein and the regulation its submolecular organization is induced by the direct action on anterior pituitary cells of the estrogens. 相似文献