British scientists claim they have created human sperm from stem cells. But other experts have questioned their data. Researchers at Newcastle University and the NorthEast England Stem Cell Institute say they used a new technique to derive what they described as sperm cells from embryonic stem cells. Newcastle research leader Karim Nayernia says the technique would allow researchers to study how sperm develops and possibly help develop treatments for infertile men. But many other British experts say they are unconvinced by the research. They also say the sperm cells created in the laboratory were clearly abnormal.
