Molecular transitions in early progenitors during human cord blood hematopoiesis. Homo sapiens

Hematopoietic stem cells give rise to diverse cell types in the blood system, yet our molecular understanding of the earliest fate decisions that generate this enormous diversity in humans remains incomplete. Here we leverage Drop-seq to individually profile more than 20,000 progenitors cells from human cord blood, without prior enrichment or depletion for individual lineages based on surface markers. Our data reveal a transcriptional 'atlas' of progenitor states in human cord blood, which we leverage to reconstruct differentiation trajectories from HSC to four downstream lineages. And we also demonstrate that Drop-seq data can be utilized to identify new heterogeneous markers of cell state. Overall design: CD34+ cells were enriched from human cord blood mononuclear cells, and mRNA profiles were generated by paired-end sequencing in Illumina HiSeq, with cDNA being amplified using the Drop-seq protocol, or a modified SMART-Seq2 protocol. Generally, 2-3 replicates were performed per biological sample.

造血干细胞（Hematopoietic stem cells, HSC）可分化为血液系统中的各类细胞类型，但目前我们对人类体内驱动这一丰富细胞多样性产生的早期命运决定的分子机制，仍缺乏完整认知。本研究借助Drop-seq技术，无需基于表面标志物对各细胞谱系进行预先富集或耗竭，即可对人脐带血中的逾20000个祖细胞开展单独转录组分析。本研究的数据揭示了人脐带血祖细胞状态的转录组图谱，并借此重构了从造血干细胞到四种下游细胞谱系的分化轨迹。同时本研究证实，Drop-seq数据可用于鉴定全新的细胞状态异质性标志物。
整体实验设计：从人脐带血单个核细胞中富集CD34阳性细胞，采用Illumina HiSeq平台进行双端测序以生成mRNA表达谱；cDNA扩增环节使用Drop-seq实验流程或改良版SMART-Seq2实验流程。每个生物学样本通常设置2-3次重复实验。