RESUMEN
Specific rabbit antisera were prepared against purified aggregation factor and its membrane-associated receptor, baseplate, derived from the marine sponge. Microciona prolifera. They were utilized in conjunction with fluorescent-labeled goat anti-rabbit IgG in an assay to demonstrate the surface localizations of both components. The specificity of antibody preparations for AF and BP was demonstrated through inhibition of the rotation-mediated assay by homotypic antibody. This study confirms the presence of aggregation factor on the surface of disaggregated sponge cells maintained in the presence of the divalent cations, Ca++ and Mg++, and its absence when cells are maintained in Ca++ and Mg++-free seawater. The location of BP could also be demonstrated on the cell surface. Aggregation factors and baseplate appear to be heavily distributed on archeocytes and choanocytes, but are localized less intensely on gray cells. Gray cells are typified by yellowish autofluorescence of their intracellular granules in stained and control preparations. The reaction of anti-Microciona aggregation factor with its homotypic factor appeared to be species specificity judged by immunofluorescence assays and by inhibition of rotation-mediated assay by anti-homotypic AF since antibodies prepared against heterotypic AF preparations were unreactive.
Asunto(s)
Agregación Celular , Poríferos/análisis , Proteoglicanos/análisis , Animales , Calcio/farmacología , Membrana Celular/análisis , Separación Celular , Técnica del Anticuerpo Fluorescente , Magnesio/farmacología , Poríferos/fisiologíaRESUMEN
HeLa cells were separated into two populations by agglutination with anti-H ulex reagent which was defined according to its reactivity against L-fucose, the immunodeterminant sugar for blood group H. Chromosome studies of individual cells from each population indicated that they were karyotypically similar and that they possessed a single modal chromosome number of 69. Studies of tissue culture supernates and of cellular fractions and their supernates showed that HeLa cell group H was membrane associated and not soluble in nature. Cloning studies of single H(-) cells separated from H(-) cells agglutinated by anti-H demonstrated progeny comprised of mixed H(-)/H(-) cells, a finding which was supported by results of population studies on typed cells grown in monolayer culture. It is believed that the H- population represents germinal cells that are capable of dividing to form mixed H(-)/H(-) cellular progeny, the former representing a more fully differentiated cell form, which eventually exfoliates and becomes nonfunctional.