Clonal dynamics in early human embryogenesis inferred from somatic mutation.
Seongyeol ParkNanda Maya MaliRyul KimJeong-Woo ChoiJunehawk LeeJoonoh LimJung Min ParkJung Woo ParkDonghyun KimTaewoo KimKijong YiJune Hyug ChoiSeong Gyu KwonJoo Hee HongJeonghwan YoukYohan AnSu Yeon KimSoo A OhYoungoh KwonDong Wan HongMoonkyu KimDong Sun KimJi Young ParkJi Won OhYoung Seok JuPublished in: Nature (2021)
Cellular dynamics and fate decision in early human embryogenesis remain largely unknown owing to the challenges of performing studies in human embryos1. Here, we explored whole-genomes of 334 single-cell colonies and targeted deep sequences of 379 bulk tissues obtained from various anatomical locations of seven recently deceased adult human donors. Using somatic mutations as an intrinsic barcode, we reconstructed early cellular phylogenies that demonstrate (1) an endogenous mutational rate that is higher in the first cell division but decreases to approximately one per cell per cell division later in life; (2) universal unequal contribution of early cells to embryo proper, resulting from early cellular bottlenecks that stochastically set aside epiblast cells within the embryo; (3) examples of varying degrees of early clonal imbalances between tissues on the left and right sides of the body, different germ layers and specific anatomical parts and organs; (4) emergence of a few ancestral cells that will substantially contribute to adult cell pools in blood and liver; and (5) presence of mitochondrial DNA heteroplasmy in the fertilized egg. Our approach also provides insights into the age-related mutational processes and loss of sex chromosomes in normal somatic cells. In sum, this study provides a foundation for future studies to complete cellular phylogenies in human embryogenesis.
Keyphrases
- single cell
- endothelial cells
- induced apoptosis
- mitochondrial dna
- cell cycle arrest
- induced pluripotent stem cells
- copy number
- pluripotent stem cells
- rna seq
- cell therapy
- stem cells
- cell death
- endoplasmic reticulum stress
- young adults
- oxidative stress
- signaling pathway
- mesenchymal stem cells
- drug delivery
- cell proliferation
- current status
- transcription factor
- pi k akt
- bone marrow