/ Dolly the sheep Content for ºÙºÙÊÓƵ en /news/cow-gene-study-shows-why-most-clones-fail <p>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.</p> December 09, 2016 - 11:52am Andy Fell /news/cow-gene-study-shows-why-most-clones-fail