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D Solter

Publications and source records attributed to D Solter.

At least 73 records · Page 4Linked to original sources

A murine stage-specific embryonic antigen (SSEA-2) is expressed on some murine SV40-transformed cells.

A stage-specific embryonic antigen-2 (SSEA-2) found on murine preimplantation embryos is maximally expressed on 4- to 8-cell stage embryos and is present in decreasing amounts of morulae and blastocysts. This antigenic determinant is also expressed on murine teratocarcinoma cells, sperm, and some, but not all, SV40-transformed mouse cell lines. Analysis of solubilized immunoprecipitates by SDS-gel electrophoresis indicates that this cell surface molecule is not the 54,000 m.w. protein shared by teratocarcinoma and SV40-transformed cell lines.

Absorption

Expression of H-2, laminin and SV40 T and TASA on differentiation of transformed murine teratocarcinoma cells.

Murine embryonal carcinoma cells (ECCs) do not express antigens of the major histocompatibility complex (H-2), but do express cell-surface molecules shared with early embryos. ECCs are also characterized by their insusceptibility to infection by various oncogenic viruses, and their ability to differentiate into a variety of adult cell types. Differentiation of ECCs in vitro can occur spontaneously or can be induced. On exposure to retinoic acid the ECC line F9 (ref. 13) differentiates into cells which have the characteristics of parietal endoderm. When ECCs are exposed to simian virus 40 (SV40), the SV40 tumour (T) antigen is not expressed, although the virus genome reaches the nucleus, and a primary transcript of the SV40 A gene is made. However, following exposure to retinoic acid, the differentiated cells, like most mouse somatic cells, are susceptible to SV40 abortive infection and synthesize large T and small t antigens. To monitor the molecular events associated with the expression of the SV40 A gene on differentiation, we have constructed an ECC line (F9 12-1) containing a single integrated copy of the SV40 genome. This was accomplished by introducing a recombinant plasmid consisting of pBR322 linked to the herpes simplex type 1 thymidine kinase gene and SV40 genome into a thymidine kinase-deficient F9 cell line. We report here that in F9 12-1 cells exposed to retinoic acid, synthesis of the SV40 A gene product(s), T and tumour-associated specific antigens (TASA), parallels the appearance of the normal hallmarks of differentiation in this cell line, H-2 antigens and the basement membrane protein laminin.

Animals

Embryo-derived teratocarcinoma: I. The role of strain and gender in the control of teratocarcinogenesis.

The role of gender and genetic (strain-specific) factors in the regulation of teratocarcinogenesis was studied by monitoring the outgrowth of benign and malignant embryo-derived teratoid tumors, i.e., teratomas and teratocarconomas in several mouse strains. Teratocarcinomas were produced in all mouse strains tested, but the ratio of teratoma to teratocarcinoma varied from one strain to another. A high yield of teratocarcinomas was obtained in A/J, BALB/cJ, DBA/2J, CBA/J and C3H/J mice, irrespective of the sex of the recipient. A low yield of teratocarcinomas was obtained in both male and female C57BL/6J and AKR/J recipients, and in 129/J female recipients. For all strains but 129/J and eventually AKR/J the sex of the recipients did not significantly affect the outgrowth of embryo-derived tumors. These data suggest the existence of mouse strains with high and low permissiveness for embryo-derived teratocarcinogenesis. The sex of the recipients may influence the yield of embryo-derived teratocarcinomas in some mouse strains but is of no consequence in others.

Animals

Teratomas.

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Animals

Cytoplasmic and nuclear protein synthesis in preimplantation mouse embryos.

Cytoplasmic and nuclear proteins synthesized by mouse embryos at different stages of preimplantation development were analyzed by two-dimensional polyacrylamide gel electrophoresis. Several nuclear-specific proteins (i.e. proteins more abundant in the nucleus than in the cytoplasm) and numerous cytoplasmic-specific proteins were observed. The trends of changes in the nuclear and cytoplasmic protein synthesis are similar. Moderate changes occur between the unfertilized egg and the zygote. Striking changes characterized by the disappearance of numerous major oocyte-specific proteins and the appearance of a large number of new, stage-specific proteins occur between the zygote and the 4- to 8-cell stages. In contrast, between the 4- and 8-cell and early blastocyst periods, only a few new proteins appear, and a small number of oocyte-specific or other stage-specific proteins disappear. Minor differences in protein synthesis were observed between the trophoblast and inner cell mass.

Animals

Monoclonal antibody defining a stage-specific mouse embryonic antigen (SSEA-1).

A monoclonal antibody derived by fusion of mouse myeloma cells with spleen cells from a mouse immunized with F9 teratocarcinoma cells is described. This antibody, which reacts with embryonal carcinoma cells of mouse and human origin and with some preimplantation stage mouse embryos, defines an embryonic stage-specific antigen. This stage-specific antigen (SSEA-1) is first detected on blastomeres of 8-cell stage embryos. Trophectodermal cells are transitorily positive; however, each cell in the inner cell mass eventually expresses this antigen.

Animals

Infection of mouse preimplantation embryos with simian virus 40 and polyoma virus.

Mouse two-cell embryos, morulae, and blastocysts were killed when infected in vitro with simian virus 40 (SV40) at high multiplicities of infection. Polyoma virus was not deleterious for preimplantation embryos, even at a very high multiplicity of infection; however, the outgrowths of polyoma-infected blastocysts disintegrated after several days of culture. Indirect immunofluorescence tests revealed the presence of SV40 T and V antigens and polyoma virus V antigen in the nuclei of trophoblastic cells. Virus-specific antigens were not found in the nuclei of cells forming inner cell masses of blastocysts or in inner cell mass-derived cells in blastocyst out-growths. The appearance of SV40 T and V antigens in the nuclei was inhibited by alphaamanitin, a RNA polymerase II inhibitor. The amount of infectious virus recovered from cultures of morulae or blastocysts on subsequent days after infection with SV40 initially declined but later increased. These points of evidence indicate that some cells of early mouse embryos are permissive for the expression of early and late functions of SV40 genome and that susceptibility to infection with polyoma virus and/or permissiveness for the expression of polyoma virus late functions develop gradually between the two-cell and blastocyst stages. Electron microscope observations showed the presence of specific complexes of membranes and virions in the cytoplasm of trophoblastic cells. Single viral particles could be found in the nuclei and also in mitochondria.

Amanitins