Fig. 3: Transcriptional characterization and distribution of lymphoid cell subpopulations.

a UMAP visualization shows the distribution of T-like cells and B-like cells after reintegration. b UMAP visualization shows the lymphoid cell subpopulation distribution after annotation. c Feature plot of selected marker genes across various lymphoid cell subpopulations. d Radar chart shows the genes selected in the enrichment pathway of different lymphoid cell subpopulations. The farther each dot is from the center position, the higher the expression value is. e Feature plot of the MPL-L and VLRA gene co-expression. f Schematic diagram depicting the involvement of the TPO/MPL signaling pathway in the biological processes of jawed vertebrates and the expression of the MPL-L gene in lamprey T-like cells. g UMAP shows the lymphoid cell subpopulation distribution in the three tissue types. The bar plot shows the number of cells in each lymphoid cell subpopulation in three tissue types. h The proportion of each lymphoid cell subpopulation in the three tissue types. The dot indicates multiple tissue samples. The box plot displays the minima, maxima, central tendency, quartile ranges, and whiskers of the data. The data presented are based on a minimum of three biological replicates per organ type: intestines (n = 5), gills (n = 6), and blood (n = 3). Statistical significance was determined using one-way ANOVA with a one-sided test approach and Tukey’s adjustment was made for multiple comparisons.