Professor Paul Knoepfler, UC Davis Genome Center, studies the epigenetic and transcriptional control mechanisms that direct stem cell fate and tissue growth. He's also a writer, recently co-authoring the book How to Build a Dragon or Die Trying: A Satirical Look at Cutting-Edge Science with his daughter Julie Knoepfler. Helen Pilcher recently reviewed the book in Nature.

For more than 35 years, scientists have tried to isolate embryonic stem cells in cows without much success. Under the right conditions, embryonic stem cells can grow indefinitely and make any other cell type or tissue, which has huge implications for creating genetically superior cows.

It has been 20 years since Dolly the sheep was successfully cloned in Scotland, but cloning mammals remains a challenge. A new study by researchers from the U.S. and France of gene expression in developing clones now shows why most cloned embryos likely fail.