Transcription profiling of mouse brains of E14.5, E16.5 and E18.5 Top2b+/+ and top2b-/- embryos to study the role of DNA Topoisomerase IIbeta in gene expression

ABSTRACT: Mice lacking topoisomerase IIbeta (Top IIbeta) are known to exhibit a perinatal death phenotype. In the current study, transcription profiles of the brains of wild type and top2beta knockout mouse embryos were generated. Surprisingly, only a small number (1-4%) of genes were affected in top2beta knockout embryos. However, the expression of nearly 30% of developmentally regulated genes was either up- or down-regulated. By contrast, the expression of genes encoding general cell growth functions and early differentiation markers was not affected, suggesting that TopIIbeta is not required for early differentiation programming, but is specifically required for the expression of developmentally regulated genes at later stages of differentiation. Consistent with this notion, immunohistochemical analysis of brain sections showed that TopIIbeta and HDAC2, a known TopIIbeta-interacting protein, were preferentially expressed in neurons which are in their later stages of differentiation. Chromatin immunoprecipitation analysis of the developing brains revealed TopIIbeta binding to the 5' region of a number of TopIIbeta-sensitive genes. Further; studies of a TopIIbeta-sensitive gene, Kcnd2, revealed the presence of TopIIbeta in the transcription unit with major binding near the promoter region. Together, these results support a role of TopIIbeta in activation/repression of developmentally regulated genes at late stages of neuronal differentiation. Experiment Overall Design: Total RNAs were isolated from the brains of E14.5, E16.5 and E18.5 Top2b+/+ and top2b-/- embryos. Corresponding biotin-labeled cRNAs were then hybridized to Affymetrix GeneChip MG_U74Av2 microarrays. Data were then uploaded and analyzed by the Rosetta Resolver® system for gene expression data analysis (Rosetta Inpharmatics®, Inc.)

ORGANISM(S): Mus musculus

SUBMITTER: Yi Lisa Lyu 

PROVIDER: E-GEOD-5458 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress