Scientists from the Institute of Physical and Chemical Research in Japan cultivated embryonic stem cells in a test tube and added proteins to coax them into developing. They had wanted it to form a recognizable organ, but were stunned to find that over 10 days, the stem cells had formed an embryonic eye:
Professor Yoshiki Sasai, lead author said: "What we've been able to do in this study is resolve a nearly century-old problem in embryology, by showing that retinal precursors have the inherent ability to give rise to the complex structure of the optic cup."
His team, who filmed the technique as it unfolded, grew floating clusters of the mouse cells in a special tissue culture in the laboratory that had previously been successfully used to make a variety of brain cells.
By adding particular proteins they were able to get the cells to build a three dimensional layered structure reminiscent of the optic cup within 10 days.