RESUMO
Brief visual experience causes rapid physiological changes in the visual cortex during early postnatal development. A possible mediator of these effects is the immediate early genes whose protein products are involved in the rapid response of neurons to transsynaptic stimulation. Here we report evidence that the levels of immediate early gene mRNAs in the visual cortex can be altered by manipulating the visual environment. Specifically, we find that brief (1 h) visual experience in dark-reared cats causes dramatic transient inductions of egr1, c-fos, and junB mRNAs in the visual cortex but not in the frontal cortex. Levels of c-jun and c-myc mRNAs are unaffected. These results suggest that select combinatorial interactions of immediate early gene proteins are an important step in the cascade of events through which visually elicited activity controls visual cortical development.
Assuntos
Lobo Frontal/fisiologia , Genes Reguladores , Visão Ocular/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Animais , Northern Blotting , Gatos , Proteínas de Ligação a DNA/genética , Escuridão , Expressão Gênica , Genes jun , Genes myc , Luz , RNA/genética , RNA/isolamento & purificação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Mapeamento por Restrição , Fatores de Transcrição/genética , Dedos de Zinco/genéticaRESUMO
Postnatal brain development involves interactions between extracellular signals and preprogrammed genetic events. Immediate early genes (IEGs) are a group of genes that are induced by extracellular signals and their protein products alter transcription by binding regulatory elements in other genes. Using Northern and slot blot analysis of total RNA isolated from visual cortex, frontal cortex, and cerebellum of cats, we have determined the postnatal development patterns of mRNA expression for 5 of these genes, c-fos, erg-1, c-jun, jun-B, and c-myc. Each gene had a distinct developmental pattern of mRNA expression, and for a given gene, these patterns were often different in different brain structures. These results suggest that temporal changes in the combinatorial interaction of different IEGs during early postnatal life are important for normal brain development.
Assuntos
Cerebelo/crescimento & desenvolvimento , Córtex Cerebral/crescimento & desenvolvimento , Regulação da Expressão Gênica , Genes Reguladores , Proto-Oncogenes , Envelhecimento , Animais , Northern Blotting , Gatos , Proteínas de Ligação a DNA/genética , Lobo Frontal/crescimento & desenvolvimento , Genes fos , Genes jun , Genes myc , Gliceraldeído-3-Fosfato Desidrogenases/genética , RNA/isolamento & purificação , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação , Fatores de Transcrição/genética , Córtex Visual/crescimento & desenvolvimento , Dedos de Zinco/genéticaRESUMO
The autologous and allogeneic immunological humoral response of breast cancer patients to breast tumours was investigated by ELISA assay of both the serum and the supernatants of transformed lymphocytes from the patients and controls. No specificity or increased titre relative to the controls was observed in serum antibody. However, when the response was dissected by the use of clones of transformed lymphocytes from the patients, considerable specificity could be demonstrated in certain clones while other clones showed a generalised specificity which contributed to the masking of the specific response in the serum. Some of these clones may have clinical potential as diagnostic and prognostic tools.
