Animation describing the research voiced by Professor Karim Nayernia:
"In the lab, we prompted embryonic stem cells like these, to develop into many different cell types. A temporary green marker stained those which had the characteristics of early sperm and they were separated out by laser.
Growing in a medium containing vitamin A derivative, these early sperm are called spermatagonia. We saw some of these later develop to form spermatocytes – where the chromosome set halves...and they then went on to form spermatid.
In our research, some of these spermatid continued to grow, elongating and pushing out a tail which enabled it to move – forming the in vitro derived sperm or IVD sperm.
They can be seen here moving under the microscope in this film from our original research project."