Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Department of Pediatrics, and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA.
Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02115, USA.
Science. 2021 Mar 19;371(6535):1249-1253. doi: 10.1126/science.abe1544.
Although cell lineage information is fundamental to understanding organismal development, very little direct information is available for humans. We performed high-depth (250×) whole-genome sequencing of multiple tissues from three individuals to identify hundreds of somatic single-nucleotide variants (sSNVs). Using these variants as "endogenous barcodes" in single cells, we reconstructed early embryonic cell divisions. Targeted sequencing of clonal sSNVs in different organs (about 25,000×) and in more than 1000 cortical single cells, as well as single-nucleus RNA sequencing and single-nucleus assay for transposase-accessible chromatin sequencing of ~100,000 cortical single cells, demonstrated asymmetric contributions of early progenitors to extraembryonic tissues, distinct germ layers, and organs. Our data suggest onset of gastrulation at an effective progenitor pool of about 170 cells and about 50 to 100 founders for the forebrain. Thus, mosaic mutations provide a permanent record of human embryonic development at very high resolution.
虽然细胞谱系信息对于理解机体发育至关重要，但人类的相关直接信息却非常有限。我们对三个人的多种组织进行了深度达 250 倍的全基因组测序，以鉴定数百个体细胞单核苷酸变异（sSNV）。我们使用这些变体作为单细胞中的“内源性条形码”，重建了早期胚胎细胞分裂。对不同器官中的克隆 sSNV（约 25,000 倍）和 1000 多个皮质单细胞中的靶向测序，以及对约 100,000 个皮质单细胞的单个核 RNA 测序和单个核转座酶可及染色质测序分析，表明早期祖细胞对胚胎外组织、不同胚层和器官有不对称的贡献。我们的数据表明，原肠胚形成始于约 170 个细胞的有效祖细胞库和约 50 到 100 个前脑祖细胞。因此，镶嵌突变以非常高的分辨率提供了人类胚胎发育的永久记录。
