Transcription of c-onc genes c-rasKi and c-fms during mouse development

We investigated the expression of cellular sequences c-rasKi and c-fms, which are homologous to the oncogenes of Kirsten rat sarcoma virus and the McDonough strain of feline sarcoma virus, during murine development and in a variety of mouse tissues. The c-rasKi gene was found to be transcribed into two mRNA species of approximately 2.0 and 4.4 kilobases, whereas a single c-fms-related transcript of approximately 3.7 kilobases was identified. The c-rasKi gene appeared to be expressed ubiquitously, since similar levels of transcripts were observed in embryos, fetuses, extraembryonal structures, and a variety of postnatal tissues. In contrast, significant expression of c-fms was found to be confined to the placenta and extraembryonal membranes (i.e., combined yolk sac and amnion). The concentration of c-fms transcripts in the placenta increased approximately 15-fold (relative to day-7 to day-9 conceptuses) during development before reaching a plateau at day 14 to 15 of gestation. The time course of cfms expression in the extraembryonal membranes appeared to parallel the stage-specific pattern observed in the placenta. The level of c-fms transcripts in the extraembryonal tissues reached a level which was approximately 20- to 50-fold greater than that in the fetus. These findings suggest that the c-fms gene product may play a role in differentiation of extraembryonal structures or in transport processes occurring in these tissues. Our results indicate that the c-onc genes analyzed in the present study exert essentially different functions during mouse development.

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Cloning and characterization of mouse extracellular-signal-regulated protein kinase 3 as a unique gene product of 100 kDa

Biochemical Journal ◽

10.1042/bj3460169 ◽

2000 ◽

Vol 346 (1) ◽

pp. 169-175 ◽

Cited By ~ 20

Author(s):

Benjamin TURGEON ◽

Marc K. SABA-EL-LEIL ◽

Sylvain MELOCHE

Keyword(s):

Protein Kinase ◽

Gene Product ◽

Mammalian Cells ◽

Chromosome 9 ◽

Mouse Tissue ◽

Mouse Development ◽

Extracellular Signal ◽

Mouse Tissues

MAP (mitogen-activated protein) kinases are a family of serine/threonine kinases that have a pivotal role in signal transduction. Here we report the cloning and characterization of a mouse homologue of extracellular-signal-regulated protein kinase (ERK)3. The mouse Erk3 cDNA encodes a predicted protein of 720 residues, which displays 94% identity with human ERK3. Transcription and translation of this cDNA in vitro generates a 100 kDa protein similar to the human gene product ERK3. Immunoblot analysis with an antibody raised against a unique sequence of ERK3 also recognizes a 100 kDa protein in mouse tissues. A single transcript of Erk3 was detected in every adult mouse tissue examined, with the highest expression being found in the brain. Interestingly, expression of Erk3 mRNA is acutely regulated during mouse development, with a peak of expression observed at embryonic day 11. The mouse Erk3 gene was mapped to a single locus on central mouse chromosome 9, adjacent to the dilute mutation locus and in a region syntenic to human chromosome 15q21. Finally, we provide several lines of evidence to support the existence of a unique Erk3 gene product of 100 kDa in mammalian cells.

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Characterization of a factor that stimulates hydrolysis of GTP bound to ras gene product p21 (GTPase-activating protein) and correlation of its activity to cell density

Molecular and Cellular Biology ◽

10.1128/mcb.8.10.4169-4173.1988 ◽

1988 ◽

Vol 8 (10) ◽

pp. 4169-4173

Author(s):

M Hoshino ◽

M Kawakita ◽

S Hattori

Keyword(s):

Gene Product ◽

Cell Density ◽

Cultured Cells ◽

Specific Activity ◽

Gtpase Activating Protein ◽

Ras Gene ◽

Cell Extracts ◽

Mouse Tissues ◽

Almost All ◽

Hydrolysis Of

The postmicrosomal fraction of the extract from NIH 3T3 and BALB/c 3T3 cells stimulated the hydrolysis of GTP bound to H-ras gene product p21 by severalfold. The stimulation was observed with normal p21 but not with p21 with valine as the 12th residue. This specificity is similar to that of GTPase-activating protein (GAP) for N-ras p21 described by M. Trahey and F. McCormick (Science 238:542-545, 1987). Consistent with this specificity, analysis of p21-bound nucleotides in living cells revealed that almost all normal p21 bound GDP, whereas oncogenic mutant p21s bound both GTP and GDP. Similar activity was also found in various mouse tissues, with brain tissue showing the highest specific activity. When cell extracts were prepared from cultured cells, there was a linear relationship between GAP activity and cell density. These results suggest the factor is involved in the regulation of cell proliferation.

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Mouse cells contain two distinct ras gene mRNA species that can be translated into a p21 onc protein

Molecular and Cellular Biology ◽

10.1128/mcb.2.11.1339-1345.1982 ◽

1982 ◽

Vol 2 (11) ◽

pp. 1339-1345

Author(s):

R W Ellis ◽

D DeFeo ◽

M E Furth ◽

E M Scolnick

Keyword(s):

Normal Mouse ◽

Velocity Sedimentation ◽

Ras Gene ◽

Mrna Species ◽

P21 Ras ◽

Murine Sarcoma Virus ◽

Sarcoma Virus ◽

Mouse Cells ◽

Murine Sarcoma

The Kirsten (Ki) and Harvey (Ha) strains of murine sarcoma virus encode a 21,000-dalton protein (p21 ras) which is the product of the transforming gene of these viruses. Normal cells express low levels of p21 ras encoded by cellular genes (Ki-ras and Ha-ras) homologous to the Ki and Ha murine sarcoma virus transformation genes. A bone marrow-derived mouse cell line, 416B, has been shown to express unusually high levels of p21 ras. In this manuscript, we investigated the molecular biology of p21 ras gene expression in 416B and other normal mouse cells. We identified four distinct polyadenylated and polysome-associated RNAs, two related to Ki-ras and two to Ha-ras. The levels in 416B cells of the two Ki-ras RNAs, sized 5.2 and 2.0 kilobases, were both elevated approximately 25-fold over levels found in normal mouse cells; there was no corresponding change in 416B cells in the levels of the two Ha-ras RNAs. We partially purified the two Ki-ras mRNAs and separated them by velocity sedimentation in sucrose density gradients. Both the 5.2- and 2.0-kilobase mRNAs could be translated in vitro into p21 ras. These results show that a cellular onc protein can be translated from two distinct cellular mRNA species.

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The Effects of External Salinity on the Drinking Rates of the Larvae of Herring, Plaice and Cod

Journal of Experimental Biology ◽

10.1242/jeb.138.1.1 ◽

1988 ◽

Vol 138 (1) ◽

pp. 1-15 ◽

Cited By ~ 1

Author(s):

P. TYTLER ◽

J. H. BLAXTER

Keyword(s):

Time Course ◽

Gadus Morhua ◽

Sea Water ◽

Fluorescein Isothiocyanate ◽

Yolk Sac ◽

Clupea Harengus ◽

Larval Stages ◽

First Feeding ◽

Fluorescein Isothiocyanate Dextran ◽

External Salinity

Drinking responses to salinity change in the larvae of herring (Clupea harengus L.), plaice (Pleuronectes platessa L.) and cod (Gadus morhua L.) were measured from the time course of uptake of dextran labelled with tritium, following immersion in solutions of 32‰ and 16‰ sea water. The yolk sac and first feeding larval stages of all three species drink in both salinities. Furthermore, post-yolk sac stages appear to adjust their drinking rates to compensate for different salinities in a manner similar to that of the adults. Drinking rates in 32‰ sea water are approximately double those in 16‰. Mass-related drinking rates of larvae are higher than those in adults, but the differences do not match the differences in surface area to mass ratios, suggesting that larval skin is less permeable to water than is adult gill epithelium. Water absorption is indicated by the evidence of concentration of dextran in the gut. The estimates of drinking rates from tritiated dextran uptake are supported by epifluorescence microscopical measurements of the uptake of fluorescein isothiocyanate dextran.

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Differentiation of the Mononuclear Phagocyte System During Mouse Embryogenesis: The Role of Transcription Factor PU.1

Blood ◽

10.1182/blood.v94.1.127.413k07_127_138 ◽

1999 ◽

Vol 94 (1) ◽

pp. 127-138 ◽

Cited By ~ 110

Author(s):

Agnieszka M. Lichanska ◽

Catherine M. Browne ◽

Gregory W. Henkel ◽

Kathleen M. Murphy ◽

Michael C. Ostrowski ◽

...

Keyword(s):

Transcription Factor ◽

Embryonic Stem ◽

Yolk Sac ◽

Secretory Product ◽

Normal Numbers ◽

Phagocytic Cells ◽

Mouse Development ◽

Mouse Embryogenesis ◽

Cultivation In Vitro

During mouse embryogenesis, macrophage-like cells arise first in the yolk sac and are produced subsequently in the liver. The onset of liver hematopoiesis is associated with the transition from primitive to definitive erythrocyte production. This report addresses the hypothesis that a similar transition in phenotype occurs in myelopoiesis. We have used whole mount in situ hybridization to detect macrophage-specific genes expressed during mouse development. The mouse c-fms mRNA, encoding the receptor for macrophage colony-stimulating factor (CSF-1), was expressed on phagocytic cells in the yolk sac and throughout the embryo before the onset of liver hematopoiesis. Similar cells were detected using the mannose receptor, the complement receptor (CR3), or the Microphthalmia transcription factor (MITF) as mRNA markers. By contrast, other markers including the F4/80 antigen, the macrophage scavenger receptor, the S-100 proteins, S100A8 and S100A9, and the secretory product lysozyme appeared later in development and appeared restricted to only a subset of c-fms–positive cells. Two-color immunolabeling on disaggregated cells confirmed that CR3 and c-fmsproteins are expressed on the same cells. Among the genes appearing later in development was the macrophage-restricted transcription factor, PU.1, which has been shown to be required for normal adult myelopoiesis. Mice with null mutations in PU.1 had normal numbers of c-fms–positive phagocytes at 11.5dpc. PU.1(−/−) embryonic stem cells were able to give rise to macrophage-like cells after cultivation in vitro. The results support previous evidence that yolk sac–derived fetal phagocytes are functionally distinct from those arising in the liver and develop via a different pathway.

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Analysis of postcapillary pH changes in blood in vivo after gas exchange

Journal of Applied Physiology ◽

10.1152/jappl.1978.44.5.770 ◽

1978 ◽

Vol 44 (5) ◽

pp. 770-781 ◽

Cited By ~ 41

Author(s):

A. Bidani ◽

E. D. Crandall ◽

R. E. Forster

Keyword(s):

Gas Exchange ◽

Time Course ◽

Quantitative Description ◽

Carbonic Anhydrase Activity ◽

Transport Processes ◽

Red Cell Membrane ◽

Ph Changes ◽

Pulmonary Capillaries ◽

Dehydration Reactions

A quantitative description of the reaction and transport processes that take place in blood during and after gas exchange in capillaries is developed and used to interpret recently reported experimental results. Included in the computation are 1) CO2-H2CO3 hydration-dehydration reactions in plasma and erythrocytes, 2) CO2 reactions with hemoglobin, 3) O2 binding to hemoglobin, 4) buffering of H+ intra- and extracellularly, 5) HCO3- Cl- exchange across the red cell membrane, 6) diffusion of gases between alveolar gas and blood, and 7) transcellular movement of water. Ion and water fluxes are described assuming passive diffusion down their electrochemical potential gradients. Recent data on the magnitude of the Bohr and Haldane shifts and on carbamate formation in the presence of 2,3-diphosphoglycerate are used. The analysis is used to examine the direction, magnitude, and time course of plasma pH changes in blood leaving the pulmonary capillaries and is shown to preduct results that agree very closely with recently reported experimental measurements in vivo. The time computed for plasma pH equilibration after gas exchange when carbonic anhydrase activity is absent from plasma is so great that blood may never be in complete electrochemical equilibrium as it travels around the circulation in normal man.

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Localization and Characterization of the src-gene Product of Rous Sarcoma Virus

Cold Spring Harbor Symposia on Quantitative Biology ◽

10.1101/sqb.1980.044.01.107 ◽

1980 ◽

Vol 44 (0) ◽

pp. 991-1005 ◽

Cited By ~ 3

Author(s):

A. R. Goldberg ◽

J. G. Krueger ◽

E. Wang

Keyword(s):

Gene Product ◽

Rous Sarcoma Virus ◽

Rous Sarcoma ◽

Src Gene ◽

Sarcoma Virus

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Developmental regulation of yolk sac hematopoiesis by Krüppel-like factor 6

Blood ◽

10.1182/blood-2005-05-1916 ◽

2006 ◽

Vol 107 (4) ◽

pp. 1357-1365 ◽

Cited By ~ 89

Author(s):

Nobuyuki Matsumoto ◽

Atsushi Kubo ◽

Huixian Liu ◽

Kuniharu Akita ◽

Friedrich Laub ◽

...

Keyword(s):

Developmental Regulation ◽

Es Cells ◽

Embryonic Stem ◽

Early Embryo ◽

Yolk Sac ◽

Homozygous Mutation ◽

Mesoderm Induction ◽

Mrna Levels ◽

Mouse Development

Krüppel-like factor 6 (KLF6) is a member of a growing family of transcription factors that share a common 3 C2H2 zinc finger DNA binding domain and have broad activity in regulating proliferation and development. We have previously established that Klf6 is expressed in neuronal tissue, hindgut, heart, lung, kidney, and limb buds during midgestation. To explore the potential role of Klf6 in mouse development, we analyzed Klf6-/- mice and found that the homozygous mutation is embryonic lethal by embryonic day (E) 12.5 and associated with markedly reduced hematopoiesis and poorly organized yolk sac vascularization. Additionally, mRNA levels of Scl and Gata1 were reduced by approximately 80% in Klf6-/- yolk sacs. To further analyze this phenotype, we generated Klf6-/- embryonic stem (ES) cells by homologous recombination, and compared their capacity to differentiate into the hematopoietic lineage with that of either Klf6+/- or Klf6+/+ ES cells. Consistent with the phenotype in the early embryo, Klf6-/- ES cells displayed significant hematopoietic defects following differentiation into EBs. Prolongation of epiblast-like cells and delays in mesoderm induction were also observed in the Klf6-/- EBs, associated with delayed expression of Brachyury, Klf1, and Gata1. Forced expression of KLF6 using a tet-inducible system enhanced the hematopoietic potential of wild-type EBs. Collectively, these findings implicate Klf6 in ES-cell differentiation and hematopoiesis.

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