Chinese researchers publish single cell spatio-temporal map of human limb development

Chinese researchers have published in the journal Nature a single cell spatio-temporal map of human limb development, shedding light on the cell evolution path and the determination process of cell spatial position in fetal limbs.

Human limbs emerge during the fourth post-conception week as mesenchymal buds, and would develop into fully formed limbs over the subsequent months. This process is orchestrated by numerous temporally and spatially restricted gene expression programs.

Despite decades of work with model organisms that have defined the fundamental mechanisms underlying vertebrate limb development, an in-depth characterization of this process in humans has yet to be performed.

A research team led by Zhang Hongbo, a professor at the Zhongshan School of Medicine at Sun Yat-sen University, innovatively used single cell transcriptome technology and single cell spatial transcriptome technology, making it possible to explore the cell evolution process.

The researchers sampled embryos successively from the beginning of the fifth post-conception week to the ninth post-conception week, and obtained more than 100,000 cells, each with about 2,000 genes. Through calculation and analysis, the team took the lead in creating a fine single cell map of human limb development including all cell types.

They then obtained the characteristics of each cell, discovered key genes, and located these genes to the path of cell evolution through DEAPLOG, an independently developed tool to perform differential expression analysis for cell clusters and other conditions.

Using this map, they can track the cell types produced at specific times and regions directly, identify entirely new cell types, and characterize the key genes activated by different kinds of cells, according to Zhang.