Gene expression analyses and distribution of H3K4me3 modification during eosinophil development (GMP to EoP to Eosinophil)

To identify regulators of homeostatic eosinophilopoiesis in mice, we took a global approach to identify genome-wide transcriptome and epigenome changes that occur during homeostasis at critical developmental stages, including eosinophil-lineage commitment (eosinophil progenitor [EoP] compared to granulocyte-monocyte progenitor [GMP]) and lineage maturation (eosinophil compared to EoP). Our analyses revealed markedly greater transcriptome alterations associated with eosinophil maturation (1199 genes) compared to eosinophil-lineage commitment (490 genes), highlighting the greater transcriptional investment necessary for differentiation. Our analyses also delineated a 976 gene eosinophil-lineage transcriptome that included a repertoire of 56 transcription factors, many of which have never previously been associated with eosinophils. Epigenomic studies revealed that genes that were specifically induced with eosinophil-lineage commitment in EoPs were “poised” with active chromatin marks in GMPs, despite not being expressed in GMPs. In contrast, a majority of the genes that were highly and specifically induced with maturation in eosinophils was not associated with poised chromatin, suggesting distinct epigenetic regulation between genes induced with lineage commitment compared to genes induced with cell maturation during eosinophil development. Overall design: RNA Seq and H3K4me3 distribution of GMPs, EoPs and eosinophils sorted from Balb/c bone marrow. RNA Seq libraries were prepared from 2 independent sorts of each cell type (GMP, EoPs, Eosinophils [Eos]). ChIP Seq was performed with chromatin from one sort of each cell type.

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Bouffi C, Kartashov AV, Schollaert KL, Chen X, Bacon WC, Weirauch MT, Barski A, Fulkerson PC