The aim of the Human Developmental Cell Atlas (HuDeCA), a three-year program initiated by Inserm in September 2019, is to build a reference atlas of embryonic and fetal human cell types. The project has been designed from the outset to enable contributions to the Human Cell Atlas (HCA), an ambitious international initiative to map all normal cell states of the body at every human life stages.
HuDeCA’s main research objective is to establish the distinguishing molecular characteristics of single cells within specific embryonic and fetal organs at chosen stages, in order to define and map cell types. It will create a multidimensional atlas of human preimplantation development combining time-lapse imaging and non-invasive biophysical methods. As in the Human Cell Atlas, pilot tissues (adrenal, cardiopharyngeal, pulmonary, pancreatic, hematopoietic, hypothalamic and ocular tissues) and stages were selected in accordance with the expertise of current HuDeCA partners.
Inserm endowed this cross-cutting scientific program outside usual funding calls in order to give more visibility to human embryological research in France, a historical strength reinforced by pioneering bioethics laws and their continued updates. It also aims to develop unique platforms and databases to make significant contributions to multiple international initiatives, including the HCA. The HuDeCA project brings together eight participating teams from distinct national institutes, comprising seventeen senior scientists (among whom the current co-PI of the Human Lung Cell Atlas v1.0, Pascal Barbry of the Institut de pharmacologie moléculaire et cellulaire in Valbonne), as well as nine additional permanent organizational contributors. This organization implies substantial new collaborative and networking efforts, coordinated by Alain Chédotal of the Institut de la Vision in Paris.
The first goal of HuDeCA is to establish a dedicated, scalable human embryonic/fetal bioresource with management tools to track and distribute samples among researchers within the consortium and, ultimately, to other research teams. The bioresource will consist in setting up a cryobank of pre-implantation human embryos as well as organizing and completing what is arguably the largest cohort in continental Europe of human embryonic or fetal samples with multiple storage modalities.
To ensure internal and external data compatibility, HuDeCA favors workflows of scRNA-seq and single-nucleus (sn)RNA-seq using 10X Genomics Chromium technology. An original aspect for validation and further research is the development of a unique imaging platform, combining state-of-the-art fluorescent molecular detection techniques in whole-mount human specimens with subsequent 3D imaging and rendering. This platform will be used to visualize gene expression products distinguishing specific human embryonic and fetal cell types and to map them at unprecedented resolution through space and time.
Finally, HuDeCA will communicate its results, challenges and achievements using European public research web infrastructures. The HuDeCA web portal (online September 2019) will be a gateway to other services allowing users to visualize and explore all uploaded transcriptomic and image data, integrating FAIR principles of data management, interoperability and accessibility. Relevant transcriptomics data will be mirrored on HCA’s Data Coordination Platform.