Cebp1 and Cebpβ transcriptional axis controls eosinophilopoiesis in zebrafish [ChIP-seq]

Eosinophils are well known to regulate host protection from parasites and have been reported to paticipate many other physiologic and pathologic processes. Understanding the role of eosinophils in these processes requires a better understanding of eosinophilopoiesis. Using a zebrafish model, we have identified an eosinophil lineage-specific marker, eslec. Using this marker we have established a Tg(eslec:eGFP) reporter line, which specifically labels zebrafish eosinophil lineage cells from early life through adulthood. Spatial-temporal analysis of eslec+ cells demonstrated organ distribution at the larval stage. By single-cell RNA-Seq of eslec+ cells, tissue-distributed eosinophils were found to have similar differentiation paths but different tissue-specific expression profiles. Genetic analysis demonstrated a Cebp1 and Cebpβ transcriptional axis that regulated eosinophilopoiesis, in which Cebp1 directly targeted cebpb to inhibit eosinophil differentiationthe commitment, differentiation, and maturation of the eosinophil lineage. In summary, this study characterized eosinophil development in multiple dimensions including spatial-temporal patterns, expression profiles, and genetic regulators. The results provide for a better understanding of eosinophilopoiesis. For the ChIP-Seq analysis of Cebp1 or Cebpβ binding regions, Tg(hsp70:cebp1-eGFP) or Tg(hsp70:cebpb-eGFP) larvae were heatshocked for the overexpression of Cebp1-eGFP or Cebpβ-eGFP. Then, the binding regions were enriched by ChIP with the anti-GFP antibody.