Human single cells were clonally expanded by culture and whole-genome sequenced. This dataset includes 334 clonal samples and 7 blood bulks from seven individuals (DB2, DB3, DB5, DB6, DB8, DB9, DB10). We extracted genomic DNA materials from clonally expanded cells and matched peripheral blood using DNeasy Blood and Tissue kits (Qiagen) according to the protocol. DNA libraries for WGS were generated by an Accel-NGS 2S Plus DNA Library Kit (Swift Biosciences) from 1 µg of genomic DNA materials. WGS was performed on either the Illumina HiSeq X platform or the NovaSeq 6000 platform to generate mean coverage of 25.2X for 374 clonally expanded cells and 94.8X for 7 matched blood tissues.

To estimate the contribution of early embryogenic cell lineages in adult tissues, we performed deep targeted sequencing on 379 bulk tissues from various organs of the five individuals (DB3, DB6, DB8, DB9, DB10). Of the 441 early embryonic mutations targeted, 411 mutations could have high-quality baits designed for them. DNA libraries were prepared by SureSelectXT Library Prep Kit (Agilent), hybridized to the appropriate capture panel, multiplexed on flow cells, and subjected to paired-end sequencing (150-bp reads) on the NovaSeq 6000 platform (Illumina) with a mean ~2,900x depth of coverage for the early mutations. Sequence reads were trimmed and mapped to the human reference genome (GRCh37) using the BWA-MEM algorithm.