Chinese scientists reconstructed a 3D model of a human embryo within two to three weeks after fertilization, which opens a new door into very early human embryonic development.

Out of ethical concerns, in-vitro culture of human embryos is limited to 14 days, and therefore, the human embryo growth between 14 and 21 days after fertilization is usually considered a "black box."

The researchers from the Institute of Zoology at the Chinese Academy of Sciences and China Agricultural University conducted high-resolution profiling on 38,562 gene spots of a human embryo and then constructed its 3D model by integrating gene expression patterns and spatial information.

Also, they have investigated the dynamic activity of signaling pathways along the embryonic body axis, according to the study published this week in the journal Cell.

The study has far-reaching clinical implications for understanding miscarriages and fetal disorders in early embryonic development, said the researchers.