Supplementary Figure 1: Cell clustering and novel cell-type-specific markers.

(a) Violin plots represent the number of genes detected by scRNA-seq in samples obtained from larvae dissociated at different time points (12hpf, 27 cells; 14hpf, 275 cells; 16hpf, 114 cells; 18hpf, 144 cells; 20hpf, 288 cells). The white bars in the centre represent the interquartile range. The black lines in the middle of the white bar represent the median value. The thin black lines extended from the white bar indicate the upper (max) and lower (min) adjacent values in the data. (b) Violin plots represent the distribution of the expression of known outer Atrial Siphon Muscle Precursors (oASMP) markers in 20hpf scRNA-seq dataset (288 cells) as per Razy-Krajka et al.¹. (c) t-SNE plots represent clusters of individual transcriptomes from 14, 16, and 18hpf samples (left), and violin plots showing expression of indicated marker genes in defined clusters. (t-SNE is not shown for the 12 hpf data because it consists of a homogeneous population of TVCs). colour codes for cell identities as in Fig. 1a. (a–c) Sample size of the violin plots and t-SNE plots (number of cells in each cell identity) is provided in Supplementary Table 6 (Data sheet: cell identity and number). (d) Figure exemplifying the gating strategy. Cell population only have tagRFP signal in the gate “RFP” were analysed again with defined gates set for tagRFP and tagBFP, cell population with both tagRFP and tagBFP in the gate “RFPBFP” are sorted for downstream genome-wide analysis. Gating strategy is described in detail in method.