We used 10X scRNA-Seq to investigate gene expression dynamics and cell type changes in four turbot immuno-organs (gill, head kidney, posterior intestine and spleen) during infection. In total, 103,055 high quality leukocytes were characterized. Our results not only provide a useful resource for the study of fish immune system, but also uncover the origins of adaptive immunity throughout vertebrate evolution. Overall design: Single-cell transcriptome dynamics of turbots during Edwardsilella piscicida EIB202 infection.