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K D Lanclos

Publications and source records attributed to K D Lanclos.

43 records · Page 3Linked to original sources
PubMed1978

Effects of estradiol-17beta in the male Xenopus laevis: isolation and translation of cytoplasmic messenger RNA populations.

Total Xenopus liver cytoplasmic RNA isolated following long-term estrogen administration (14 days) was fractioned using Sepharose 4B chromatography. One of the Sepharose 4B peaks was shown to contain RNA with a molecular weight reported for vitellogenin mRNA (approximately 34S). The presence of estrogen-induced vitellogenin mRNA in the peak 5 RNA was determined by translation of the RNA in the oocyte and analysis of the oocyte translational products by immunoprecipitation with anti-vitellogenin. Sepharose 4B peaks 2 and 3 were also observed to contain estrogen induced mRNA populations sedimenting between 9--18S. These findings suggest that Sepharose 4B chromatography might prove useful in separating different mRNA populations following estrogen-induced gene activation.

Animals↗
PubMed1978

Effects of estradiol on early messenger RNA in male Xenopus laevis liver.

Cytoplasmic RNA isolated from male Xenopus liver between 1 and 6 h of hormone treatment was separated into distinct classes by Sepharose 4B chromatography. Assay of the mRNA activity of these RNA species in the wheat germ cell-free system demonstrated 2 populations of mRNA activity (peak 2 and peak 3). The activity of 1 population of mRNA (peak 2) was inducible by estradiol while the other (peak 3) remained unaltered for at least 6 h. mRNAs obtained by Sepharose 4B chromatography were also translated in the Xenopus oocyte. The translation products were analyzed by Sephadex chromatography and SDS-gel electrophoresis.

Animals↗
PubMed1976

The formation of poly A-containing RNA in rat liver after administration of 3-methylcholanthrene.

The incorporation of [32P] orthophosphate into liver poly A-rich cytoplasmic RNA was investigated in rats which were pretreated with 3-methyl cholanthrene (3MC) or with the vehicle, corn oil. This incorporation was markedly increased within 6 h after administration of the polycyclic hydrocarbon and reached a maximum by 24 h, i.e., 33-fold increase. The poly A-rich RNA fraction was examined by gel electrophoresis and the specific activity of individual species was shown to be elevated.

Animals↗
PubMed1975

Translation of hormone-induced messenger RNA in amphibian oocytes: I. Induction by estrogen of messenger RNA encoded for vitellogenic protein in the liver of the male African clawed toad (Xenopus laevis).

Induction of the synthesis of the vitellogenic proteins, lipovitellin and phosvitin, in the liver of the male African clawed toad (Xenopus laevis) was investigated as a function of time after treatment with estradiol-17beta [1,3,5(10)-estratriene-3,17beta-diol]. The appearance of mRNAs encoded for lipovitellin and phosvitin in the cytoplasmic fraction of the liver was assayed by microinjections of hepatic mRNA preparation [either polyribosomes or poly(A)-rich RNA] into oocytes obtained from mature female toads. Oocytes were then incubated in the presence of radioactive amino acid(s) at 19 degrees for periods of time varying from 4 to 18 hr after microinjection. The results show that at 2 hr after hormone treatment more mRNA was present in the cytoplasm, and that from 2 to 72 hr after treatment the level of induced mRNA increased almost linearly to 110% above the control values. Experiments employing specific lipovitellin antiserum indicated no radioactive lipovitellin among the proteins synthesized in oocytes microinjected with hepatic mRNAs isolated from 3 to 9 hr after hormone treatment. However, a marked synthesis of immunoprecipitable, radioactive lipovitellin and an enhanced incorporation of [3H]serine occurred in the oocytes microinjected with hepatic mRNA preparations obtained from toads treated with hormone for 12 or more hr. The identities of the proteins encoded by the mRNAs induced early in estrogen action (2-9 hr) in the male amphibian liver are unknown. It is surmised that some of these proteins may function in the regulation of the subsequent synthesis of the vitellogenic proteins.

Animals↗