2.6.6.ScRNA-seq data pre-processing
The single cell transcriptomic data of the 9 samples of human embryonic
tooth germ including incisors and molars from PCW12 to PCW18 were
acquired from the GEO database (GSE184749). The quality control
screening was used for low-quality cells filtration (≤200 genes or
≥20,000 genes, >10% mitochondrial genes). In total, 23530
cells were adopted for further analyses. PCA was performed for
normalization based on the top 2000 highly variable genes, then R
package harmony was applied to correct the batch effect. UMAP method was
applied for dimensional reduction.